January 2012

  By Cyril Courtois  (RCM CAD Design Drafting ltd.)

  www.loghomedesign.ca

Topic: About smaller homes…

Introduction:
Within the last half century, North American homes have more than doubled in size becoming castles to impress by volume alone. 
Real estate agents define a home by it square footage, number of bedrooms and bathrooms and pictures of luxuriously furnished formal living and dining rooms that are left unused by its occupants.
Due to high building and energy costs, dwindling investments, savings and pensions and an emerging consciousness not to waste and embrace “green concepts”, designing a home is now much less about impressing our neighbors and friends with size and wow factor.
Instead today’s house design trend is all about quality and function within a manageable budget.
Creating a house that nurture a personal connection to each rooms and is customized to fit our family life style and needs, becomes a home to be enjoyed every day by all.

1-   Why downsizing your dream home…

First, the word “downsizing” is associated with economic recession and unstable business situation, hardly a positive concept.
In the 1950s homes averaged under 1000sqft and regular family size was huge.
Today family size is a fraction of yesterday’s, with retiring baby boomers being the bulk of new home owners.

We downsize because the huge houses we lived in during the 80s, 90s… do not make much sense anymore.
Planning a smaller home is smart because…

1- It is much more affordable as it requires less building materials, labor and land.

2- It cost much less to heat in winter, keep cool in summer and upkeep during its lifetime.

3-However the most powerful reason to go smaller is because the space defined by the rooms tend to be more to human scale, therefore cozier, with everything important within reach.

Massive great rooms with high vaulted ceilings do have that wow factor that is difficult to resist. It can be filled when you entertain large group of friends and it then feels great.
However if you are alone, you will (perhaps unconsciously) choose a smaller area within the perimeter of that room to relax like a bay window sit, an alcove with lower ceiling or even a corner by the fireplace.
If that large room has nothing designed for a simple single or double occupancy, then it will probably remain empty as you may migrate to that small den around the corner…

2- How to downsize the dream?

First understand how you live now by listing all your activities in each room and time spent using all those rooms.
This exercise will quickly help you identify the rooms you use the least and the most important rooms for your life style.
Rooms do not need to be conceived around a singular activity.
A room can be designed to serve many different functions especially if small alcoves are created for single use (reading, house bookkeeping, homework, internet surfing…)

A- The kitchen.

In  the old days the kitchen was a private room by itself, out of the way from the main living area.
Today the kitchen has become the centre of activity of the household where family and even guests will congregate.
It is the heart of the home and needs to be open to the dining and sitting area. The kitchen is highly visible so it has become a show case room called the theatre gourmet kitchen.
It is so big, it is exhausting to work in, as appliances and work areas are so far away from each other.
Remember that kitchen square footage is the most expensive in the house.
Any professional chef will tell you that they would rather work in a compact kitchen where all is at hand with minimum walking around.
Managing storage space is a key to a great easy to use kitchen within a smaller space.
Lower cabinets should have drawers instead of shelves.
All content in open drawers are readily accessible and little space is lost above when closed.
Deeper counter from common 24″ deep to 30″ deep provides more working area and more drawer storage below.
Use ceiling height upper cabinets to maximize storage for rarely used items.

If you want to impress your friends, you can invest in multi function appliances to save space and have the latest from Europe.
The Multiplo from Scholtes is a great compact multi purpose counter top appliance that can roast, boil, steam, fry and slow cook within its own stainless steel containers, thus eliminating the need for pots and pans.
A large capacity oven with internal partition allows cooking different dishes at same time.
A Quooker’s instant boiling water tap saves much time when making tea, coffee, bleaching vegetables or sterilizing kitchen utensils… while probably using less energy than a kettle.

Add an island or peninsula for more preparation counter space, storage space below and a sitting bar to talk to the cook or have breakfast…

B-The dining room.

Some houses design have a large dining room with chandeliers, a nook off the kitchen and a eating bar at the island.
That is overkill for the smaller home concept.
I think a large dining table is a must if you ever will entertain.
However that table can be located right by the kitchen because everyone loves to be around the kitchen.
Dirty dishes can be stacked away in dishwasher, hidden in deep kitchen sink or behind a raised countertop.
At our house the dining table which is right along the kitchen is daily used by our kids for homework…
The dining table is a great place to hang out as a family when cooking meals.

C- The bathroom(s).

It is the second most expensive space in the house after the kitchen.
A bath for each occupants of a home is a cost that can be avoided.
In Europe the toilet with sink has its own private room and the bathroom means sink and shower (or bath tub).
If several people are likely to use a bathroom at same time of the day, split the toilet area from the shower/sink area.
Showers are much more in use by active professionals and elderly than bath tubs. 
Stacked bathrooms at each level of living space is a good design option to consider.
The most common model is one bathroom for parents and one for children.

D- Rooms with shared functions…

A home office can be readily transformed into a TV room, a guest bedroom (with a murphy bed for example) or an away room for quiet times.

A back entry, mudroom and laundry are commonly combined into one.

The entry or foyer should have a cloak closet , a bench and shoe storage and possibly a powder room for guests.

E- Storages.

The smaller home can not stand clutter. 
To feel spacious it must have extensive built in storage to put away what is not in use or be seen.

Detail design is key for the smaller home just like on a boat or RV.
Do not hesitate to create storage under stairs, in no headroom area below the roof, under bay window seat, floor to ceiling closets on each side of corridor…
Add wall recess for custom cabinets and alcoves for small computer desk, sleeping booth and reading recess.

F- Tips to make the smaller home feel bigger.

Add decks, covered patio, sunroom, screened porch around the house to extend the house for outdoor living with matching floor patterns from inside outward.

Use natural light from two sides of a room.

Use light, color and scale contrast to expand a room space.
Work with the third dimension (ceiling and floor heights) to define different spaces in a room.

Use thick window/door jambs and large baseboards.
Avoid narrow hallways.

Design diagonal views within the house to make the inside space feel bigger.

3- Our dreams versus the hard reality of cost.

The cheapest house to build is a two full level rectangular to square framed box with vinyl windows and exterior siding, an asphalt roof on manufactured frame trusses, commonly called the colonial house. You get the most amount of living space for the least amount of exterior walls and roof cover.
Headroom is 8 foot high in all rooms with no vaulted ceilings.
Interior trim work is minimum, ceilings and interior walls are sheet rock.
It works as a starter home in a city subdivision but this is not the dream home for our retirement years after the kids move out…

The dream home has spirit and is a personal expression of your tastes and lifestyle.
It is specifically designed for your building site to take advantage of slopes, views and sun…
Quality of construction and quality of interior and exterior finishes is high, so more expensive than the regular city house.
It may be a house with much wood millwork and stain glass or the so popular timber frame home or even a handcrafted log home with those massive logs you see in magazines or web pages dedicated to that timeless construction style.

To fit your budget, a quality home may need to be scaled down so the dream becomes reality.
It too often comes down to a choice between how big and how beautiful and comfortable.
It does not mean settling for less but rather being smart with each square footage of space.
Detail design makes all the difference.
A 3000 square foot poorly designed unpersonalized stock plan can feel smaller and sterile compared to a cozy 1200 square foot professionally designed  smaller home with private spaces and detailed storages like on a boat.

4- Professional design.

Hire a good house design professional that can help you make the necessary transition between wishes and reality by identifying what matters less for you to allow your house dream to come true.

Topic: Settling for log home construction styles

Definition:
When a stacked log wall reduces in overall height, it is called settling, a well known occurrence in log home construction.

Introduction:
Settling in log homes can occur in three ways: compaction, slumping and most significantly, radial shrinkage of the logs.

  A-   Compaction occurs mainly in log construction using cope style lateral groves where the interior and exterior sharp corners of the cope are the only contact with log below. The cumulative weight of logs, roof and snow above crush these contacting lines of wood fiber into the log below, creating a tight seal between stacked logs.
Compaction can account for up to 1% height reduction of a log wall.
Compaction is minimal for logs with large contact areas like tongue and grooved flat to flat log profiles.

B-   Slumping is an old problem applicable to cope style grooves, that is practically eliminated with a kerf cut at top length of log to control cracks or checks in the wood as it loses moisture content.
If no kerf is cut, check will appear at cope as it is closest opening to core of log and the log will slightly open up at cope creating a slumping of the log over the one below.

C-   Most settling in log homes happens because of radial shrinkage of the logs as the wood dries out.

Moisture content (MC) of wood is defined as a percentage of its wet weight (water and fiber) against its oven dry weight (fiber).
Depending on the wood species and world location, living trees moisture content varies from 50%, up to 200%.
It is quite common for living trees to have 100% moisture content, which means it is half water and half fiber in weight.
Wood cells are like interconnected pipes with sugary water inside the cell and in the cell wall.
When a tree is cut down, the water in the cells readily flows out and evaporate.  This process can take months or even years.
When the cell water is gone the wood has reached its fiber saturation point (FSP) usually somewhere around 27% MC.
Above that point, wood is dimensionally stable.Wood does not shrink until moisture content gets below its fiber saturation point.
Only then is the water locked in the wood cell wall able to drain which causes the cell to start collapsing on itself, just like an apple left to dry will shrivel onto itself.

Logs mostly shrink radially.  Soft woods like Pine, Spruce, Fir, Cedar… which are commonly used in log construction, lose about 4% of their diameter to shrinkage.  That is, from FSP to the Equilibrium moisture content (EMC), which is determined by where the log home is built.
Logs also shrink in length, but it is almost negligible, at up to 0.2% maximum.  A 10′ tall log post will shrink in height by less than 1/4”.

EMC varies greatly by location ranging from 4% to 20% in North America.  It also can noticeably swing between seasons. 
In Beijing, China, EMC is 7% in January and 14% in July.
That is an unusually wide seasonal EMC differential!
That would translate to roughly a 1% change in log diameter between winter and summer, which is more than 1 inch difference for a 9 foot high log wall between a swollen to a shrunken state depending on the season.

Radial shrinkage (%) = S x (MC-EMC) / FSP 

To evaluate the % of radial shrinkage to expect for a log at a certain location, multiply S (total radial shrinkage for wood specie used) by the difference between MC (wood moisture content taken with a moisture meter) and EMC (equilibrium moisture content at specific location), and divide by FSP (fiber saturation point for that wood specie). 
S is a known value specific to each wood specie, ranging from about 2 to 5% for soft wood and between 3.5 to 7% for hard wood.

D-   Why should we care about this radial shrinkage of wood in log and timber construction?
Homes that are built with horizontal logs will lose wall height.
If well known design and construction practices are not applied to counteract settling, windows and doors will be damaged and crushed, plumbing stacks and water lines will shatter, beams will fail under too much load, second floors will warp and roofs will leak…
Construction practices such as adding settling space above doors and windows, adding screw jacks under posts to lower them as log walls settle, adding slip joints to plumbing stacks and flexible water lines en route to second floor baths, are a few of the many proven building solutions to log home construction.

E-   Settling and log construction styles

   1-Handcrafted log construction
Two basic types…

Scribed Fit	Chinked style

The scandinavian scribe fit has cross corners and laterals that stay tight during the settling process.
Usually built with green logs that are seasoned from 20% to 35% MC. Estimated settling is 6% with (4% shrinkage, 1% compression and 1% safety allowance)
The lowest logs in the wall (sill log) must start at same height and top logs (cap log) must complete the log wall at about same height to avoid settling differential in the house.

The chinked style has tight cross corners but laterals are not closed.  An elastomeric compound called chinking is applied to close gaps inside and outside.  Chinking material and labor costs are high as well as upkeep costs to reapply chinking.

Using dead standing logs does not eliminate any settling issues as logs MC is still much higher than EMC to be reached.

The MC of logs that are kiln dried gets down to, at best, 18% at the center, because massive logs and timbers can not be fully dried at the core.  Again all settling issues are in effect.

The log standard defines that a log wall with no more than 0.5% settling can be designed and built as a non-settling wall.  However, when more than 0.5% settling occurs, screw jacks and settling spaces above all static building parts of the home must be added to the design.

A log post and beam structure is considered to be non-settling construction, even when a double cap log is used.

A fusion style log home is a mix between a full stack log home and a post and beam style.  It is a settling log structure, as three stacked logs from floor up, then a short post to a large horizontal log beam at top adds up to four logs stacked, and this equals 1 to 2% settling to the total wall height, too much to be allowed to pass as a none settling log wall.

A piece en piece log construction home is a post and beam structure with horizontal log fillers between posts from sill to cap log.  Those filler logs will settle by about 5%, so design steps must be taken to counteract the settling.Static horizontal stacked log assembly can be achieved by simply pounding lags or rebar from one log to the log below. In this case, the log wall will not settle as the lags or rebar will lock each log in a static position to the log below to form the wall. However, tight corner wood joinery (cross corner, dovetail…) will be lost as the drying logs will separate at corners and laterals when they shrink away from each other.  The loss of the tight corner weakens the log structure and chinking is a must to fill all those gaps! Another problem with adding all that steel inside the log walls is condensation. In winter, moisture loaded air from heated living spaces meet the cold dry air from outside at the center of the logs. That moisture will condense on the steel and slowly rot the wood around it, thus weakening the tight fit between steel and wood. This problem is mostly overlooked as it can take years to be noticeable, but it is real and documented.

Some log manufacturers advertise non-settling patented log wall systems using some rather complex steel pipe assembly inside the log wall to lock the logs in position.  The same problems mentioned above with lags and rebar is present in this system.

I quote Alex Charvat engineer, owner of Alexander Structures a structural engineer firm specializing in log construction that also conducts research and testing for the log home industry…
“Even though those systems are patented and unique, it may merely be a complicated solution to a simple problem… in other words, a marketing gimmick.”

A note about thru bolts…
I highly recommend thru bolts, usually 5/8” threaded rods to tighten log walls from sill log to cap log as a proven engineered system for seismic and wind lateral loads.
Although it means adding steel inside the log wall, there are self draining by simply placing a split washer at bottom to allow moisture to drip away.

Laminated logs, or sometimes called engineered logs, are truly the only non-settling stacked log construction available on the market.
The laminated log is composed of glued layers of kiln dry boards (usually 1 1/2” thick), milled into a common round or square profile.  Each board, being so thin, can easily be kiln dried down to 8 - 10% MC, making them very stable and almost check free in the process.  They do not settle as they are already so dry and the flat contact area between stacked logs means no compaction or slumping.  However, laminated log walls exposed to the outside air will regularly contract and expand with seasonal EMC.  Windows and doors still need to be independent of the log wall.  This is achieved by using spline boards and a small settling space above, as they are fragile, non-structural, and expensive house building components. (See detail below)
Laminated logs do have glue lines visible at log ends which can be considered unsightly to some.  The glue lines can be somewhat hidden with fine sanding and a darker stain at those locations.
Because of all the extra manufacturing work needed to produce them, laminated log home total prices can be up to 15% more expensive compared to standard milled log homes.

1- Laminated log wall
2- header log above window
3- Box liner header (same width as log wall thickness)
4- Spline board loose fit in slotted log wall
5- Back rod foam gasket
6- Slot in log ends
7- Foam gasket at interior and exterior in compression between box liner and log wall to stop air leaks.
8- Box liner vertical jamb.
9- Header trim board nailed directly to log header and overlapping trim board below nailed to box liner header only.
10- Spacer trim board nailed to header log to offset Header trim at 9.
11- Vertical trim board nailed to vertical box liner jamb only.
12- spacer vertical board if window jamb width is smaller than window log wall opening width. Using a box liner allows using a smaller jamb width window than wall thickness.
13- Window jamb nailed to box liner at vertical and top. Window sill is nailed directly to log wall.
14- Window glazing
15- Sill trim is nailed to window sill.

  Last word…
Settling of a log home is unavoidable unless logs, as dry as the local environment, are used (laminated).
Hiring an log home experienced and knowledgable designer / architect to prepare your log home plans is a safe step to ensure success for your log building project.
Working with trades that have already been involved with that type of construction is a big plus.

Sources:

1987 Wood handbook: Wood as an engineering material. USDA,
Agricultural handbook #72

Log building standard (International log builders association)

Equilibrium Moisture content of wood in Outdoor locations in the USA and worldwide.  USDA Forest service.

Topic: Geothermal home heating and cooling.

Introduction:
On our planet Earth, air, ground and water store close to half the energy striking it’s surface from the sun.
This huge store of renewable solar energy can be tapped using a heat pump to heat our homes in winter. 
Also, in the summer, that same heat pump can be reversed to provide air conditioning for our comfort.
The US Environmental Protection Agency (EPA) states that ground source systems can save 30% to 70% of home heating costs compared to natural gas, propane, electricity, oil or coal. 
In the summer, cooling costs can be lowered from 20% to 50%.

Type of heat pumps available:

A-  Air source heat pump (ASHP) works great in mild to moderate climates and are the most popular heat pump system used in the USA because of its low purchase and installation cost.
They are dependable and durable, as they have been on the market for many decades.
The air source heat pump has an outdoor heat exchanger and compressor, as well as an interior heat exchanger with a forced air distribution system to deliver cooling and heating to the building.
They are noisy when running, so they may need to be located away from living space.
Their operating efficiency drops dramatically as outside air  temperature drops below freezing.

B-  Ground source heat pump (GSHP) or GeoExchange works fine in all climates, and are the best choice for cold winter areas.
GSHP uses a refrigerant to water base heat exchanger instead of refrigerant to air exchanger for ASHP.
They have a ground water loop located ten feet below the Earth’s surface where the temperature remains fairly constant at around 10 C or 50 F, with negligible seasonal fluctuation.
In winter, the GSHP draws the heat from the ground water loop heat exchanger, and compresses that heat using a vapor compression refrigeration cycle (like our kitchen refrigerator) and releases that heat to the house by forced air, in-floor hydronic heating or baseboard radiators.
In summer the process is reversed for cooling with forced air delivery inside the home. The GSHP can also dehumidify and filter the air circulating in each room.

1- Loop systems:
Source of heat for a GSHP can be the ground, surface water (like a lake or pond) or a drilled well.

Open Loop System:
Where ground water is abundant, this ground water heat pump system is likely the most efficient and least expensive to install due to its simplicity.
Water is drawn from bottom of a well directly to the heat pump heat exchanger, where its heat is extracted (or added). The water is pumped back into the aquifer using a discharge well that is away from source well.
A Surface water heat pump system draws water from a pond, lake or river.
Water must be tested for hardness, acidity and organic matter which can clog or corrode a heat exchanger and pump.  Open loop systems have been outlawed in many municipalities because of environmental concerns.

The standing column well is much more friendly to the environment. It is a specialized open loop system using a deep well  about 6” in diameter.  Water from the bottom of the deep rock well is drawn and circulated through the heat pump heat exchanger and then returned to the top of the well from where it exchanges heat with the surrounding rock as it travels downward back to the bottom of the well which can also be used as a source of potable water for small demand.  This system is a great choice for where bedrock is close to the surface, but not any deeper than 200′ because of drilling and pumping costs.
Depending on the size of the heat pump, make sure 5 to 12 gallons of water per minute is steadily available in the heating and cooling season if applicable.  

Closed loop system:
Most locations do not have sufficient ground water to operate an open loop system, or this system is banned because of environmental regulations or local codes.  
Because of this, closed loop systems are most common for residential application.

The oldest and simplest type of closed loop system is the Direct Exchange geothermal heat pump (DX).
The ground heat transfer is done by circulating refrigerant in a single copper tube loop buried underground and directly connected to the heat pump.
Despite the higher cost of copper, DX will cost less to install compared to other closed loop water systems, as it requires only about 25% of tube length, thus reducing excavation costs.
This is do to the high thermal conductivity in copper compared to the high density polyethylene pipes used by water loop heat pumps.
Also DX is noticeably more efficient as it does not need a water pump nor a water heat exchanger to refrigerant which creates heat losses.
However refrigerant loops are more prone to gas leaks.  Expensive brazed copper tubes protected from corrosion in acidic soils is also required.

The most common is the closed loop water system
A pump circulates an antifreeze water solution in a plastic pipe buried underground below the local frost line. The heat transfer is achieved by a water heat exchanger to the refrigerant loop at the heat pump (usually located inside the house basement or crawl space).
If adequate land area is available to install the water loop and the ground is easy to dig, then a horizontal ground closed loop is the cheapest solution.
400 to 600 feet of horizontal loop per ton of heating (12 000 btu/h) is required (A 2000 square foot home that is well insulated will need about three tons of heating).
The size of the loop needs to be calculated by an experienced professional, who takes into consideration the average ground temperature, type of soil and its moisture content.  Dryer ground loops are less efficient than wet ground loops.
A body of water (lake or pond) is the most efficient way to transfer heat using a sunken closed loop.
Where land for a horizontal loop is not available, or the ground is difficult to dig, then a vertical ground closed loop may be installed by boring holes 100 to 500 feet deep, and then dropping a pair of tubes connected at the bottom of the hole.
To assure best heat transfer, bentonite grout is poured in the bored hole to maximize thermal connection between plastic tubes and surrounding ground.
The cost of installing a vertical loop are generally twice the cost of installing a horizontal loop because of the additional drilling costs.

2- How does a GSHP affect the environment?
About 70% of energy used in the GSHP system comes from free, renewable solar energy stored in the ground or surface water.
The other 30% is the electricity used to run the pumps and compressor.
A heat pump system moves 3 to 4 times more heat energy than it consumes in electricity.  It does not burn fossil fuels, so it does not create any pollution locally.
Because the heat pump uses electricity to run, its impact on the environment depends on how that electricity was generated.
In Canada, where electricity production emits lower levels of green house gases, operation of a heat pump has less impact on the environment than any fossil fuel heating system, including high efficiency natural gas furnaces.
In the USA, where electricity production is highly reliant on coal, natural gas furnaces have less impact on the environment.

3- Is a heat pump a sound investment?
GSHP capital costs are much higher than traditional heating and cooling systems, however operational costs are much lower, with realistic savings between 20% to 60% per year.
The average cost of a GSHP system in the US is $10,000.  In Canada, it is $20,000, with high end systems reaching above $30,000. 
GSHP reliability and efficiency are constantly improving, however the purchase price is also escalating at about 2 to 5 times more compared to a conventional system.  Payback averages 12 years compared to natural gas, and about 5 years compared to electricity.
From personal design experience, so far, only a few upscale homes that we designed, have opted to buy a GSHP.
However, with fuel energy costs on the rise, and capital costs for heat pumps likely going down because of increased popularity, attractive government and utility companies subsidies, and many more builders aware of the advantages of GSHP, I believe GSHP will soon be a sound investment for new homeowners in all income brackets .

Topic: Water heating options for your new home.

Introduction:
Heating water typically uses 10% to 25% of the overall energy spent to run your home, and is the second largest energy expenditure after heating and cooling.

Water heater options:

A/  Storage tank water heaters are by far the main choice in North America.
They are cheaply mass produced, and have an average life expectancy of 10 years, depending on your water quality.
Tank heating efficiency will go down due to sediment accumulation, and scaling on elements.
Five year warranty is the norm.
They run on electricity or gas, and most common tank capacity ranges from 40 to 60 gallons, but, can be up to 100 gallons depending on your family needs.
Although electric water heaters are cheaper to buy and install, gas heaters are much cheaper to run because electricity is much more expensive per BTU than gas.
If you have natural gas to your property, or propane gas delivery available, then it is well worth going with gas and spend more for installation (gas vent).

To improve water heating efficiency in your home…
1- Use less hot water by selecting low flow faucets and shower heads.
              Bathroom faucet at 1 gallon per minute (GPM)
              Kitchen faucet at 2 GPM
              Shower heads at maximum 2 GPM
2- Turn down your water heater thermostat to 60 C (140 F), but no lower than 55 C (130 F) to avoid risk of bacteria.
This also slows mineral build up and corrosion thus increasing tank life expectancy at top efficiency.
3- Insulate all hot water lines and install insulating blanket on your tank.
4- Purchase an increased efficiency water heater or a condensing water heater for best performance.
Select electronic ignition instead of pilot light option to save energy for gas powered water tanks.

B/  Solar water heaters can save 50% or more of a home’s hot water expenses, even in the cloudy Pacific Northwest.
They are the most cost effective way to harness solar energy, since they absorb solar radiation, rather than just sunlight. Even in the cold winter months they can work as water preheaters in conjunction with a hot water system.
Most likely tax credits and grants are available for new homes and renovations in your area.
Solar collectors will require up to 6 m2 (65 ft2) of south facing roof space with minimal shading.
Evacuated tubes are best compared to flat plate solar collectors as (when mounted on a south facing roof slope), they are designed to track the sun from east to west.
Refer to diagram below.

Lifetime of this system ranges from 25 to 40 years and the installed cost start from $7000.00 for a family of four.
It will typically take 10 to 15 years to payback the investment.

C/  Tankless water heaters or, on demand water heaters, heat water when needed, thus eliminating stand by heat loss common to conventional water tanks which constantly store 40 or more gallons of hot water all year round.
Compared to hot water tanks, they are at least double the initial investment. Energy tax credits and grants are available in most regions.
However, they also last at least twenty years, double the lifespan of a conventional water tank. They also save energy, with the payback taking seven to fifteen years.
An added benefit is their small size, not much bigger than an electric panel, which means saving precious living space.
They are available as point of use (for each bathroom or kitchen sink and dishwasher), or they also come as larger units, or multiple units able to supply hot water to the whole house…
Beside the energy savings, their main attraction is that they can provide hot water endlessly. No more running out of hot water in the middle of a shower!

As with conventional water tanks, there are two main energy sources:

Electric powered tankless heaters demand large amount of electricity to run at peak demand time of the day.
  Some local power companies do not allow them as they draw so much power at peak consumption time (eg. showering in the morning).

Gas powered tankless heaters make much more sense, as both natural and propane gas are much cheaper to run them.

However, remember that choosing gas means you need to
vent the unit, so it will need to be placed on a perimeter wall for direct venting, or otherwise a chimney will be required for central locations.

Sizing your tankless unit to your needs is an important step before buying. There are two main things that you will need to know: The flow rate and the temperature rise.

Flow Rate:
You will need to calculate the amount of water the unit must heat by measuring the flow rate in GPM of every faucet, appliance, shower and bath it is connected to.

Temperature Rise:
You need to know the temperature of the cold water before it enters the tankless heater, and how hot you wish the water to be when it comes out. The difference between the cold and hot water is the temperature rise. The cold water coming to your house from the city, or well is dependent on location of your property.
When you know the flow rate and temperature rise required, a properly size heater can be selected to maximize energy savings and ensure desired hot water temperature at the tap.

D/  An interesting and inexpensive way to reduce the temperature rise, is to install a drain water heat recovery heat exchanger to raise the temperature of incoming cold water.

Typically, 80% or more of the energy used to heat your home’s hot water goes down the drain when you take a shower, bath, use the dishwasher or wash your clothes. A grey water heat recovery system will preheat the cold water entering your water heater by using a simple heat exchanger as shown in diagram.

It requires no power to run and has no moving parts.
The cost of this system ranges from $400 to $700 depending on length of heat exchanger and diameter of the vertical copper drain pipe which the cold water pipes are coiled around.
Of course the fresh incoming water does not mix with the drain water at any time.
You can expect about 20% savings or more on hot water heating cost and payback is three to four years.

Last words…
Energy costs are high and will continue to rise relentlessly.
As you are planning to build a new home, I recommend you research all available options to save energy.
We all need hot water for our home use, but at what cost?

Solar water heating technology is beginning to make more sense than ever, and solar energy is free. Payback time on that investment will continue to get shorter, as energy costs keeps on rising.
Tankless gas water heaters are a great fit with solar systems as they bring the water to desired heat level in the cold winter months.
Drain water heat recovery is a simple technology that works well with both solar and tankless systems to maximize your energy savings for your hot water needs.

Topic: Custom design and drafting of construction set of plans for your future log, timber or conventional frame construction home.

Introduction:

Unless you have significant architectural and building experience, designing a home is likely a daunting endeavor to most future homeowners.
Your first step is to define what you like; and to a certain extent, also what you dislike. Almost endless architectural styles are available from simple log cabin, traditional timber frame, cap cod, colonial, Feng shui, historic, passive solar, victorian, modern or contemporary to name a few…

Building a dream…

Gather ideas by reading architectural magazines and researching the internet, downloading exterior and interior photos and floor plans.
Visit open houses and show homes and take pictures if possible.

From dream to reality…

Calculating your building budget is a crucial step to avoid cruel disappointments. The cost of building varies greatly by location, construction style and design. Inquiring with local general contractors about custom home cost per square foot in your area is a wise thing to do.
If you are planning to build a log home, a timber frame or log/timber accent frame home for example, then ask log or timber frame builders about the extra cost that is likely included with this type of construction. This gathering of information will help you define how much living space you can afford, or are willing to spend.

Do you own a building lot?

It is our strong belief that a custom home is site specific to take advantage of orientation to views, passive solar gain, topography of the land and environmental impact. By buying a stock plan, and dropping it on a site you have not purchased will deny you the opportunity to fine tune your favorite floor plan to fit just right on your property.

Beware of copyright infringements.

All designs you will find are copyrighted, and you should protect yourself from possible legal pursuit by buying the design of your choice if you do wish to build it.
Many of our customers come to us with a plan they believe is just what they want. After we sit down and review their needs, budget and how well the design will fit the building site, the final product often ends up quite different from the original ideas, to their great satisfaction.

Buying a stock plan or hiring a home designer or an architect?
A stock plan typically will cost you a few hundred dollars to upward of $1000.00 depending on the size and construction style. Stock plans are not site specific, and not structurally engineered to your local weather and soil conditions.
The set of plans will have minimum information for building permits, and local building inspector review will likely require the plans to be customized to fit local codes and bylaws, local site snow load, wind load, and soil bearing pressure. In the end, you will be building someone else dream and miss the chance to build what you want and need.

Home designers professional qualifications range from no post secondary education, to college and university architectural graduates and fees vary greatly from less than $1.00 per square foot to upward of 1% of the finished house building cost.
When selecting a home designer, look for years of experience in the industry, check portfolio for creativity and architectural style, education and references from previous customers and builders.
In North America it is not required to be a licensed architect to design residential projects.

Licensed architect firms mainly design public and commercial buildings with some residential work. An architect will typically charge between 7% to 12% of total cost of a project. Their fees reflect a deeper involvement in the building process, well beyond the design and drafting of construction plans.
An architect will prepare bid documentation, including construction specifications for contractors and trades, site analysis, and may assist with planning and zoning, environmental studies manage construction contracts and coordinate project with engineers, interior decorators, landscape architects…
Architects may go as far as designing specific furniture, dish and cutlery sets to match your home design architectural style.

The design process from RCM CAD DESIGN DRAFTING LTD:
Preliminary design stage:
The first step is to gather all necessary information about the site.
Zoning, soil and weather data, snow and wind load, seismic zone, allowable building envelope, applicable building codes, local bylaws, building and environmental restrictions…
We work with you to establish your targeted budget, as well as architectural and construction style with pictures and written/oral description of space relationship and size of rooms with possible desired orientation to view and sun, access and egress to house, including services location.
Photos of building site and views from all sides with orientation to North, South, West, East is helpful. A plat map of the property with grade elevations at the building site should also be available.
RCM CAD provides a detailed questionnaire to help you focus on the most critical aspect of the design.
The preliminary design package we provide includes fully dimensioned floor plans with structural design of log/timber work (size and support), rendered pictures of the house on your virtual building site and a virtual walkthru animation to allow our customer to visit their future home inside and outside, view furnished rooms with appliances and cabinetry as shown on our web page rendering samples.
The virtual walkthru is an essential and powerful visual tool that allows the customer to fully understand room sizes and relationships with traffic space and outdoor living. If you would like to view a walkthru sample, simply email us at rcmcad@loghomedesign.ca and we will send a sample walkthru to you so that you may experience the usefulness of this tool before you even begin building.

Design development:
After receiving your feedback on all aspects of the preliminary design proposal, we start the revision process to fine tune your home to your complete satisfaction. Typically it only takes 1 to 2 revisions, but we include up to 3 revisions in our process. Good communication by email and phone or face to face is essential.

After this, we work on the final construction set of plans. Construction plans consist of drafting a set of plans ready for a structural engineering stamp, if required, and building permit approval. The quality of the final set, including custom construction details from concrete foundation to roof, is essential to ensure that you will get precise construction quotes from all builders involved in the quotation process.
Our set of plans includes:

# A cover page with a perspective view of your home and general construction notes.
# Four elevations: front, back, left and right as required for building permit.
# Foundation plan and/or basement plan
# Main floor plan and floor framing plan
# Upper floor plan and floor framing plan.
# Roof framing plan
# Electrical plan for each floor with electrical schedule and wiring details
# Two full sections across the house showing stair calculations, headroom and distance between floors…
# Workshop drawings of log and timber work (if applicable) showing all walls and roof beams fully dimensioned (length, size and elevations from top of main floor.
# Custom construction details for concrete, framing, log and timber connections, steel anchors and finishing details
# Window and door schedule for each floor with nominal and rough opening dimensions.
# Finishing schedules for all floors, walls and ceilings.
# Two isometric views to get a birds eye-view of the log/timber work (if applicable).
# Final virtual walkthru is also available for you and all builders.

Timing:
Preliminary designs take about two weeks to produce from the time we receive down payment. Revisions typically take one week each. Drafting of plans takes two weeks in most cases. Larger projects do tend to take longer.
A set of plans by RCM CAD consists of about 15-20 pages (D size 2′x3′ at 1/4” per foot scale) for regular job sizes.
Please view our plan samples on our web page design section for more information.

Why is a good detailed set of plan essential to the success of your home building project?
All that we build or manufacture starts with a plan precisely detailing all facets of construction to ensure a successful end product whether it is a bicycle, a car, a piece of furniture or a house.
A house is a large investment that requires much attention to all details.

Some people believe that eliminating or minimizing the design process and buying the cheapest plans possible will save them money.
The opposite is actually true.
A quality set of plans, professionally designed and drafted, will save you many times the cost of the plans.

1. A good design is worked within a set budget, eliminating the dreadful possibility of running out of money before the house is ready to move in.
2. Eliminating wasted space and optimizing traffic flow will save on overall size of the home.
3. Judicious material selection and simpler construction practices can save large amounts of money. Designers with many years of experience can make a big difference in helping make all the right decisions.
4. A set of house plans that leaves many guesses will be difficult to impossible to estimate material and labor costs.
   If the builder has to guess, it will invariably cost you more money.
   You do not want to have the builder interpret the plans.
   All builders will charge more when finding grey area in the design to protect themselves from surprises.
5. You, the future home owner must understand the design. Regular floor plans and elevations only show a tiny part of the design. A virtual walkthru of your home will ensure that you will not be surprised when the home is built, as you will have viewed the design in 3 dimensions.
6. If you ask the builder to change the design as it is being built because you suddenly realize it is not what you expected, you will have to pay cost overruns. All cost overruns can simply be avoided with a good design from the start.
7.  If, in the unfortunate event you have a conflict with your builder, your plans and building contract are the legal documents you will depend on. All quotations are based on plans, so the more detailed the plans, the better your legal protection. Ask a lawyer…

Conclusion:

We at RCM CAD DESIGN strongly recommend all future home owners hire an independent professional team, free from conflict of interests, and working just for you, to design and draft quality set of plans and therefore ensuring a successful and happy home building experience.

Topic: The masonry stove or thermal mass heater

Introduction:
Over ten years ago, I met Chris Hedderson from Rocky Mountain environment Technologies outside the Denver log home show. Chris had an outside booth with a masonry stove (modular refractory kit) fired up within a large tent. While it was a very cold weekend, I recall how toasty warm it was inside that tent. I kept his business card and after much research, knew that one day I would install my own stove.
I did just that last summer. This newsletter is a follow up from newsletter 08.
Within the last chapter of this newsletter, I am writing about my personal experience about heating and cooking with our masonry stove at our cabin by the lake.

Definition:
The masonry stove is a free standing heat storage fireplace.
It is a very efficient heating device that burns wood rapidly because of massive airflow intake.
A one hour fire heats the masonry mass which gently radiates the heat to the living space for 12 to 24 hours depending on how well the house is insulated, outdoor temperatures and house design. Radiant heat is absorbed by all the mass of the house. In turn, the walls, floors and furniture heat the air so there is no need to install fans, motors or duct work. No reliance on electricity is another step towards “self sufficiency”. Log homes are particularly suited to the use of masonry stoves as the log walls are huge passive mass heat storage.
Masonry stoves use only a small fraction of fuel compared to other stoves as their combustion efficiency has been rated at over 90%!

History:
Over two thousand years ago, the Romans invented the hypocaust (heat from below) to heat their masonry public baths and private house floors, channeling the smoke exhaust from a single wood fire from one side of the room to a chimney on the other side.
The birth of today’s masonry stove dates from the 17th and 18th century as a direct response to an acute energy crisis precipitated by an overuse of timber for building and heating.
European governments ordered their craftsmen to develop fuel efficient stoves. The Swedish, Finnish, Russian, German and Austrian masonry
stoves all use the same idea of sending a hot, fast fire on a long path through a masonry mass that absorbs the heat. The trapped heat is then
released slowly.
Today the Finnish government encourages the construction of masonry stoves for all new homes. Courtesy of generous tax incentives about 90% of new homes in Finland are heated with wood burning masonry heaters thus reducing the demand for electricity, oil and gas. This lowers the country’s dependency on foreign energy sources.

Design
As log/timber home designers, we almost always incorporate a fireplace or wood stove in the design.
Unfortunately a common reason to add a wood burning fireplace in new homes is for resale value and as an afterthought for using on special occasions only.
Few future homeowners plan to use a wood burning heater regularly for both heating and visual enjoyment.
A masonry stove is both a heater and thanks to today’s large glass door it can become the family entertainment center. It has the potential to reintroduce the hearth as the vital center of home and family life.
For our ancestors there was no home, no family, no life without a fire.
Instead of making the fireplace an optional design item carelessly slapped on an exterior wall in our living room, we can bring back the“magic warmth and hypnotic fire dance” to the center of our main living space, thus drawing the whole family together around this eternal source of comfort and serenity.
The masonry stove can be much more than a heater. It can have a baking oven for bread, pizza or casseroles… a warm bench designed within its mass or even a bed on top, a design feature so common in Eastern Europe.
The masonry heater complex becomes the heart of the home, and the room layout of our home can flow outward from that center…

Construction:
The design and operation of the masonry stove is remarkably simple.
As the firebox is masonry, the fire burns to 1500 degrees Fahrenheit or more, insuring full combustion of the gases contained in the wood.
Heating energy produced by wood complete combustion comes from 1/3 solids and two third gases.
Combustion efficiency measures the heat energy produced to completely burn wood fuel (for example) with little or no air pollution.
Heating efficiency measures how quickly the heat generated by a fire is released into the living space.
Steel wood stoves so common in North America have a low combustion efficiency as they do not get hot enough (about 500
degrees) to burn all the gases contained in wood thus the production of creosote and the necessity to clean chimneys regularly. However they do achieve high heat transfer efficiency as metal transmits heat within minutes of the fire being lit.
My masonry stove does start to heat our cabin within 15 minutes of being lit, mainly from the front glass door. The cold thermal mass of the stove for the first season fire will start to feel warm to the touch after two hours of burn.
The masonry fireplace kit (constructed of castable recycled refractory firebrick) I bought from Chris weighs over 2000 lbs. The outer masonry layer of bricks and chimney is another 2000 lbs for a total load over 4000 lbs which requires a substantial concrete footing with rebar in the crawl space for structural support.
The air comes from outside, channeled through the crawl space by an 8” diameter steel pipe to the air damper just before it enters the base of the fireplace. I open the air damper to full during the burning and close it when the fire is out to stop cold outside air from entering and cooling the stove. The fresh air enters the firebox from the bottom through a 2” wide long slot that doubles as the ash drop. I plan to clean the small amount of ash produced by the stove yearly by accessing the ash clean out door situated in the crawl space.
It took six hours to assemble the masonry kit including the baking oven and install the butterfly smoke damper at the base of the firebox. Then I
covered the inner core with cardboard before starting to lay the outer brick layer so that the outer layer is never touching or cemented to the inner core.
This is a crucial step as the inner core gets very hot and expands under heat stress. The outer brick or stone layer is never too hot to touch even
during intense fires, making the masonry heater so much safer thansteel stoves.
I recycled old bricks to build the envelope around the inner core. As I had no previous masonry experience, it took me weeks to complete this job and build the chimney to 17′ high, the minimum required for a strong exhaust draft.
As part of the design a chimney clean out door is installed at the base of the chimney in line with the smoke damper so I can see past the butterfly damper all the way across the bottom of the heater for future inspection. To ensure a chimney draft is established on a first firing of a cold stove, we use this door access to the chimney to insert a crumpled ball of paper and light it to heat up the column of cold air trapped in the chimney. That creates a strong draft upward and then we light up the top of the wood pile in the stove, close the door and enjoy a fire that comes alive almost in an instant without any smoke seeping in to the living space.

Lighting the stove, The top burn fire:
I only use well seasoned wood. I collect green wood, cut it to proper length and season it for a year under cover. Then I split the wood in smaller pieces ranging from about 4” diameter to kindling size and let it season another year to make sure it is dry and ready to provide me with an intense fire. Green or wet wood is not efficient for the masonry heater! Energy is actually consumed to heat and vaporize the water contained in green wood.
To create a one hour burn fire, use the top burn method of stacking about 40 lbs of wood in the stove.
Burning one pound of wood generates close to 7000 BTU.
40 lbs will release about 280 000 BTU. As the masonry stove has a combustion efficiency over 90%, the stove can produce about 250 000 BTU from one fully loaded fire burn!
Larger 3” to 4” piece are first stacked in a crisscross pattern at the bottom of the firebox. Use smaller size wood piece as the stack gets higher. Small kindling and bark or paper complete the pile. Lighting the load from the top allows the firebox to heat up and greatly reduces smoke emissions. I only see smoke coming out of the chimney in the first seven minutes of lighting the fire. After that no visible smoke comes out during the rest of the firing.
When the fire nears the end, we start to partially close the exhaust damper while only small yellow flames are still visible.
I close the smoke damper 90 % when there are no visible flames and only red ambers left. Then I close the fresh air damper to trap all the stored heat in the masonry thermal mass. When the red coals are gone I close the exhaust damper completely.
These steps maximize the efficiency of the stove by minimizing the amount of heat escaping through the chimney.

The Masonry stove and your safety:
A- Masonry heaters do not burn to the touch except the metal and glass door at the front of the firebox. They are much safer than steel stoves around children as the brick or stone finish is always safe to touch.

B- Masonry stove fires reach such high internal temperatures that they burn off the creosote right in the firebox. There is no creosote buildup on the interior channels or chimney walls. Chimney fires are not an issue so masonry heaters are known to be a low fire hazard by insurance companies.

The Masonry stove and your health:
Each time I have started a fire in a regular steel wood stove or opened the door to reload, smoke invaded our living space, creating much indoor pollution.
This simply does not happens with the masonry stove. After many dozen firings of our stove, I have yet to see or smell any smoke when we start the fire or during operation.
Masonry stoves earn LEED points for indoor air quality in the US green building council’s LEED for home’s rating system.
Particulate emissions (outdoor pollution) are 1 to 2 grams/hour which belongs to a super low emissions category. The US environmental protection agency (EPA) does not require certification for masonry heaters.
Masonry stoves heat the home by radiation and not by convection. The indoor air is not heated so it does not lose it’s moisture content, benefiting the occupants, indoor plants and even furniture. A forced air furnaces heats and blows air, not only drying the air but actually causing a “wind chill” effect. The warmer air goes up and the cooler air rushes past your feet.

Maintenance:
As already mentioned, chimney cleaning is not needed as there is no creosote build up.
After so many firing of our stove, I am astounded to notice the walls of the firebox are as clean as the first time I lit the stove.. I understand that the high heat achieved in the firebox burns away any black marks that appear in the beginning of the firing.
Proper combustion ensures that little ash remains. This can be cleaned out every few weeks through a clean out door in a raised hearth.

The air wash door design from the RME Technologies stove keeps the door glass perfectly clean. That was not the case with any steel wood stoves that I used in the past. I had to periodically clean the glass with a specific cleaner made for that purpose if I wanted to fully view the fire.

Last words… from personal experience.
Because I built my stove using recycled bricks and ceramic flues froman old masonry fireplace, I spent $5000.00 to complete this project.
My costs include the masonry kit delivered from Rocky Mountain Environmental Technologies in Edmonton Alberta, the air damper, ash door in the crawl space and many bags of “S” type masonry cement.
If I had hired a professional mason to build it and bought bricks and ceramic flues, I estimate the cost would have probably been up to $14000.00
As the attached photos of the firing cycle shows, my stove looks rustic and amateurish. A professional mason would have done a much better job laying the bricks…
I have experimented with baking using both the firebox for high temperature cooking after the fire is out and the baking oven for slow cooking casseroles with delicious success.

By Cyril Courtois  (RCM CAD Design Drafting ltd.)
www.loghomedesign.ca

Topic: Solar energy log home design

Three main solar energy systems are available for household energy needs.

1-Photovoltaic power generation systems are designed to produce electricity when sunlight hits photovoltaic panels usually installed on roof slopes with southern exposure.
Those systems may cost up to $100 000.00 for an average size home to meet its energy needs. Performance drops sharply to negligible level for cloudy days.
For properties off the grid, it may be cheaper to install panels and batteries instead of connecting to power line miles away. Check for availability of government grants and loans in your area.
To determine feasibility of a solar electric system for your home, consult sunlight performance logs taken over many years closest to your building location.

2-Solar water heating produces hot water for showering, washing dishes and even heating your home!
Passive water heating systems rely on convection or thermo-siphoning to circulate water from absorber tube panels to a hot water tank above. This system is used for summer cabins and although inexpensive, is less efficient than an active system because of the slow water flow rate.
An active system uses pumps to move hot water to storage tank which can be installed below and away from collectors.
An open loop active system pumps water through the collector panels down to the holding tank and/or directly to be used in the house. This system is for summer use or works in areas where it does not freeze.
A closed loop active system pumps glycol water antifreeze through the solar panels to a heat exchanger. The heat is then transferred to the potable water. It can be used in freezing weather.
In many locations, solar water heating may not warm your hot water enough to run a dishwasher properly or for a scalding hot shower. Using solar water heating in conjunction with a gas fueled tankless water on demand will considerably lower operating costs.

3-Passive solar heating is about designing your log home to capture sunlight using south facing windows thus converting the sun’s energy to heat the inside of your home.

A/ Maximizing solar exposure at your building site.
The best orientation for your passive solar log home is true south (northern Hemisphere). Within 10 degree to east or west, solar gain is close to 100%. A common solar home footprint shape is usually a long rectangle with a long south facing wall, including lots of windows to collect the sunlight. Kitchen is usually located on the north side and at the north east corner to enjoy the morning sun at breakfast time. Two story homes are more energy efficient and comes at a lower construction cost.
Although winter solar gain only decreases to 92% at 22 1/2 degrees off true south and respectively down to 70% at 45 degrees, summer solar gain is greater the further the house solar collectors (window and door glazing) orientation deviates from true south, thus creating serious overheating in the summer months.

B/ Glazing: For optimal solar performance, locate most of the house glazing on the south wall. However beware off over glazing, a common mistake of the past. Have only minimal windows on the north side. Windows on the east and west side should also be minimal to control summer solar heat gain unless you need light or have a view to consider.
Use low-e glass (low heat emissivity) whenever you expect unwanted solar heat transfer in or out of a particular window in the house design.
Interior thermo-shutters are a great way to dramatically reduce window heat loss at night. A common design consist of bifold foam panels sandwiched by 1/4” plywood sheathing. Curtains can be attached to the interior facing side for a pleasing decorative finish.
You may plant deciduous trees to block the summer sun, install exterior shutters, roll blinds, sunscreens at those windows. Better, build covered decks/patios on east and west sides or add arbor to grow vines to protect the log walls from weathering.
Evergreen trees on the north side is a great winter wind break.

C/ Roof overhang is the fixed projection of the roof beyond the exterior wall and its length must be carefully calculated to block the high summer sun from entering the house thru the south glazing. However the roof overhang is short enough to allow the low winter sun to flood the inside of the house.
The amount of roof overhangs is proportionate to the height of the window opening and location on the wall and a factor of the latitude of the building site.
Some design flexibility is required to account for different daily solar gain by season for a same latitude.
A log home situated in the pacific north west will likely receive little sun in the middle of the winter because the sky is mainly overcast. In this case roof overhangs are reduced to allow sun heat in the fall and early spring.
Montana receives much more sunlight in the winter and roof overhangs will likely be a bit longer to block the sun in the fall and early spring, to prevent overheating.
Roof overhang calculations are site specific and should be handled by a knowledgeable designer/architect.
Architectural computer programs using 3D modeling of your log home can precisely calculate the right amount of overhangs needed at your site for each window openings, taking in account your local heating requirements and seasonal sunlight availability.

D/ The thermal mass of your log home are the exterior and interior log walls, masonry fireplace, concrete floors…
The solar heat that enters the house during the day must be stored to be slowly released the following cold winter night, like a thermal battery.
The Trombe wall is a solar collector including a south facing glass wall with an air space between it and a dark concrete wall inside. When the sun heat passes thru the glass, the concrete wall stores the heat and radiates it back to the inside of the house.With vents installed at top and bottom of the wall, warm air rises between the glass and the wall, then flow in the living space from the top vents.
Unfortunately the reverse airflow occurs when the sun is gone, sucking the heat out of the living space. To stop this loss, exterior insulated panels would need to be deployed every time the sunlight is not hitting the glazing. This is obviously not a viable option. As well, building a concrete wall on the south facing side of your home instead of enjoying view and day light is hard to imagine for most of us.
The solar slab is a more sensible idea engineered by James Kachadorian in the late 1970’s. The sunlight would hit the south facing side of an insulated concrete slab with vents and fans circulating air under the slab from north to south of the building. However moisture can easily build up in those buried vents creating a mildew and mold problem, thus contaminating the indoor air supply of the house.
A simple well insulated concrete slab for a walk out basement floor can act as a thermal storage collecting sun heat from south facing glazing. As well a light weight concrete in-floor heating slab over a framed main floor system can also collect that sun heat and add more thermal mass storage to the house.
Much has been debated about the thermal mass of log walls.
About two years ago I visited a large log home in Arizona that RCM CAD designed many years ago.
The owner had installed an expensive air conditioning system for his log home and never used it as he was able to keep the house cool all summer long by simply running an exhaust fan upstairs at night. The day heat never had a chance to heat the logs to the point where the heat would penetrate the house as he was able to take advantage of the cool night air to cool off the log walls from within. The thermal mass of the exterior log walls worked well to avoid using the expensive air conditioning system.
Thermal mass slows down heat transfer and is proportional to the thickness of the log walls.
Providing it is a clear day, the winter sun can warm the logwork in the day, releasing that stored heat back inside the home when the sun is gone.
The R value of wood hovers between R 1.2 and R 1.5 per inch of thickness, depending of wood specie. D-fir being a denser wood has a lower R value and Western Red Cedar being a lighter wood has a higher R value.
Handcrafted log walls about 13” (33cm) diameter midspan are comparable to 2×6 frame walls with (R 19) fiberglass insulation .
Wood acts as a solid insulation and does not require any plastic vapor barrier on the inside or moisture barrier on the outside as frame walls do.
Log walls also store heat from sun light and from interior radiant heat source like wood stoves or masonry stoves, creating an even temperature interior environment, day and night.
A masonry stove is a great back up heat in solar home design and when placed where the winter sunlight can hit it, they act as another massive solar storage for your home.

Last word…
Passive solar heating and cooling your log home follows simple principles that have been discovered centuries ago by our ancestors.
However designing your solar log home requires precise calculations for sizing roof overhangs and adequate thermal mass for your specific building site.
Exposure of the main glazing side of your log home should be to the South to maximize winter solar gain and keep the sun heat away from entering the house in summer thanks to adequately designed roof overhangs and use of shutters, sunscreens, covered decks and landscaping for example…

By Cyril Courtois  (RCM CAD Design Drafting ltd.)
www.loghomedesign.ca

Topic: Lateral resistance of log walls to earthquake and wind loads.

Earthquake and wind forces act on a building in the lateral direction or parallel to the ground. Engineers call this lateral loading.
Earthquake and wind are natural phenomena laterally acting on a building.
However, they are fundamentally very different forces that call for unique and specific design solutions.
Earthquakes:
Earthquakes produce the most natural destruction to our homes on a terrifying grand scale.
The Haiti Earthquake of last month is the latest deadly reminder that we must design our homes to withstand natural destruction.  The knowledge and building technology is available. Log construction is one of many solutions…
Earthquakes alone do not kill. The buildings we design kill its occupants as they collapse over our heads because they are not adequately designed and engineered to withstand local seismic forces.

In January 1995 a devastating earth quake struck Kobe in Japan.

Since 1993, I had been designing log homes mainly for the Japanese market. Log homes are popular in that country because Japanese consumers believe log homes are able to withstand seismic tremors better than other type of construction. Watching the news, I was shocked to view the almost total devastation of the city… except a few homes were still standing untouched among all the rubble. Those were log homes…
Log homes are uncommonly strong to lateral movement created by earthquake or wind forces because the interlocking log cross-corners, the friction between logs in the long laterals and the weight of the logs can provide great flexibility and resistance against lateral forces. Earthquakes displace the ground laterally thus shaking our buildings from the foundation all the way to the roof.

The key to designing earthquake proof buildings is to find ways to absorb as much seismic energy within the flexibility of the building material and structural deformation but keep enough structural stiffness to hold the building together so it will not collapse.
Engineering adequate anchorage of the bottom logs to the foundation is essential to prevent uplift of the log shell from seismic forces. Using 5/8” diameter anchor bolts anchored a minimum 8” deep in concrete foundation and spaced at 32” on center to tie in the sill log to the foundation is a common construction specification to keep friction between the sill or bottom log and the concrete foundation. However, anchor bolts will lose tightness as the sill logs lose moisture content and shrink.

Using thru bolts tied to the anchor bolt with couplers all the way to the top log is a good solution favored by engineers.
Thru bolts are only necessary in seismic areas and are not used in low seismic zones like Texas or Minnesota for example. This works as long as the thru bolts are regularly tightened during the settling of the log walls which can take up to five years when using green logs.
Unfortunately, experience tells us that home owners almost always forget to maintain thru bolt tightness during the settling of the log walls.
Some log builders go as far as visiting the log homes they built to tighten thru bolts and adjust screwjacks at bottom or top of vertical log posts to ensure the log shell will settle evenly and keep friction to a maximum. Using automatic pressure springs at top of log walls in this instance is a solution to keep adequate friction between log to log and log to foundation.
For detailed information on log homes versus seismic and wind lateral loads, please refer to the most excellent study written by Structural Engineer Tom Hahney @2000 “How log buildings resist lateral loads” published in Log Building News, October 2000.
Tom Hahney concludes: “Log buildings survive quite well in an earthquake as long as they stay on their foundation. In fact log joinery helps dissipate the seismic energy”.

Wind:
Lateral forces created by wind depends on the wind velocity at the building site, the building shape and roof slopes and as well how much the site is protected by topography and trees.In hurricane areas, roof slopes are usually low to lessen lateral wind load. Hip roofs are also best as they do not offer much grip to the wind compared to roofs with many valleys.
During a wind storm the roof is likely the weakest part of the house and it will be the first part of the building to be blown off, so special attention must be taken to ensure the roof is securely attached to the log walls.
As log home roof overhangs should be designed to protrude at least 4’ to 5’ beyond exterior log walls to protect the log work from weathering, roof systems must be engineered to be fastened with lag screws to top plate logs, and plate logs in turn may need to be lagged or thru bolted to logs below to prevent wind uplift forces.
If the logs are large diameter, the weight of the top logs is often sufficient to anchor the roof.
If the local wind load is expected to be high, then the top logs need to be lagged or thru bolted to lower logs and possibly foundation to maximize friction between logs and the overall dead load the roof is attached to (Figure 3).

Large glass towards the local wind direction needs special attention during the design and engineering of the building.
Avoid large garage doors and opt for multiple single car garage doors instead of the double type.
A quick internet search will guide you to many historic examples of log homes surviving hurricane force winds in Florida, North & South Carolina…

Screwjacks (adjustable threaded rods) at vertical posts supporting deck roofs, (used to be adjusted to handle log wall settling) should be installed at the bottom of the post instead of the top where it creates a weak hinge point vulnerable to wind loads. Too many deck roofs have collapsed due to that simple design mistake.
As a general rule screwjacks should be installed under posts to avoid structural failure to lateral forces, inside and outside the log shell. 90 degree upright screwjack installation is crucial to maximize its load bearing capacity. A five degree off plumb position can easily half the bearing strength.
Screwjacks must be engineered for all point loads in the log structure.

Last word…
Log home design has evolved from the simple almost windowless log cabin with four cross corners built by the American pioneers two hundred years ago, to large complex log homes with huge glass walls and high vaulted ceilings maximizing view and grandiose interior space, thus weakening the log home structure ability to withstand lateral loads.
Log walls with cross corners at both ends have unique lateral load resistance capabilities superior to conventional wood frame building systems and have great seismic dissipation characteristics allowing them to survive powerful earthquakes.
However, it is crucial that the design takes in account local seismic and wind loads. Further structural engineering analysis is a must to ensure your log home will stand against nature’s extremes.

By Cyril Courtois  (RCM CAD Design Drafting ltd.)
www.loghomedesign.ca

Topic: Solid log/timber homes and fire safety

According to US National Fire Association, leading causes of occupancy related home fires start:
1-In the kitchen when cooking is left unattended
2-From heating systems that are not professionally checked and maintained.
3-From bad smoking habits resulting in bedding or couch/armchair smoldering.

- Fire resistance of solid log/timber homes
As a designer of log homes, I often encountered difficulties convincing local building departments all over North America of the great fire resistance of log walls. Designing solid log walls between attached garage and house living space was a problem as building inspector insisted on covering the log walls with a layer of gypsum wallboard!
In 2001 Dr. Dalibor Houdek conducted laboratory tests to measure the fire resistance of a scribe fit solid log wall.
The log wall withstood 3 hours of 1100 degree Celsius or 2000 degree Fahrenheit fire on one side before losing its load bearing capacity and integrity.
Please refer to Dalibor Houdek “ Fire resistance of log walls” published by Log Building News @ International log builders association Number 35, September 2001 for more details.
Solid log walls that are a minimum of 6” thick at the narrowest point are now accepted as the equivalent to one hour fire-resistive rated construction by building codes in North America.

As far as the walls are concerned, log walls do not have the cavities common to regular frame home construction where fire can easily spread as soon as the fire has caught one part of the wood frame.

Wood char insulates against fire:
Although logs are made of wood which is combustible, log walls act as a fire wall because the charring effect of wood (wood turning to charcoal) creates a protective barrier over the surface of massive log/timber members, acting as a strong retardant against the assault of fire.
The burning rate of massive wood varies from 1.6 inch per hour (D-fir) to 2.2 inch per hour (Pine) allowing the massive wood structure to remain sound for one, two or three hours depending on structural design.
For comparison, steel structures at 1000 degree Fahrenheit lose 50 % of its strength and quickly bend and buckle.
Please note that log/timber burns twice as fast in the vertical position compared to the horizontal (as log homes are built).

Comparing stack log/timber construction to post and beam:
Massive log/timber wall construction spreads the loads above (second floor and roof for example) into the entire log wall structure, enabling a log home to stay structurally sound for hours while on fire.
Post and beam construction will collapse much quicker because above structural loads are concentrated on a few posts that are usually exposed to fire from three or four sides at once.

Fire containment:
Log/timber homes are most likely built in rural areas instead of cities were building density is a fire issue to consider.
Log home building site locations in rural areas make them vulnerable to forest and bush fires.
Your home can be designed to minimize that risk.

-Clear all fuel sources from around your home from 30 feet to 100 feet depending on level of fire hazard in the area.

-Vinyl windows are not recommended. Metal clad windows with multiple glazing with a minimum one tempered pane are a better choice. All exterior doors should be solid core, exterior metal clad.

-Use class “A” fire resistance roof covering like concrete, clay, slate, metal tiles. Avoid asphalt or wood shingles.

-Roof fascia must be 2” nominal thickness minimum solid wood or stucco. Eaves should be enclosed with 7/8” thick stucco or 5/8” Type”X” drywall and no vents should be allowed to suck red ambers into the roof system.

-Gutters and downspout to be noncombustible material.

-Firewood storage to be at least 30 feet from house or in enclosed building.

-Concrete patio on grade around the house is a great choice. Decking surfaces, exterior stairs and balconies should be constructed of ignition resistant material or heavy timber or fire retardant treated wood.

-Install an outdoor sprinkling system to cover roof and immediate surrounding area. A man made water supply such as a pond can be a good investment with minimum 1000 gallons per minute flow for 30 minutes being recommended.

-A minimum of two ¾” water faucets with hose connection served by ¾” waterline prior to any water flow reducers at outside perimeter of the house is a must.

-Install proper spark arresters in all chimneys for fireplaces and heating appliances.

Fire detection and fire suppression systems:

Smoke alarms:
A working smoke alarm detects smoke and sound the alarm giving house occupants time to escape. They save lives at a very low cost and are mandatory in all occupancy buildings by all building codes in North America.
They should be placed at each floor, in all sleeping rooms as well just outside bedrooms. As smoke rises, best location is on ceiling or high on wall. Avoid installing them close to bathrooms, windows, ceiling fans and of course heating and cooking appliances.
As smoke alarms are battery powered or have a battery back up, test them monthly and replace the battery at least once a year. They should be interconnected and hardwired directly to house electrical wiring for new buildings.
Heat alarm in the kitchen is code in many countries as a smoke alarm is not advisable close to cooking appliances.

Residential sprinkler systems:
Smoke alarm only alert occupants to a fire in a building.
Sprinklers can contain or extinguish a fire.
8 out of 10 fire deaths happen in residential homes.
They are no instances of death by fire in residential homes equipped with a working inspected fire sprinkler system.
Municipalities across North America are adopting bylaws requiring all new homes to have sprinkler systems installed.
It is only a matter of a few more years before fire codes across the continent regulate mandatory fire sprinkler installation in all new homes.
Schools, factories, commercial and office buildings, as well as multiple occupancy housing are all required by law to have operating sprinkler systems.
There is much resistance by the home builders industry to force new homeowners to install sprinklers because installed cost adds an average of 1% to 1.5% to the overall building budget.
There is much information available online for or against home sprinkler installation. It can get quite confusing reading all the conflicting pros and cons claims.

An independent home fire sprinkler cost assessment study dated September 2008 prepared by Newport Partners Davidsonville, MD has impressed me greatly.
The research encompassed 10 very different communities in North America (9 in the USA and 1 in Canada).
The results shows that cost of sprinkler system vary significantly from $0.38 to $3.66 per sprinklered square foot depending on water supply source (municipal or on site), use of cheap CPVC piping compared to copper piping, need to use anti-freeze for freeze protection in winter…
A sprinkler system can cost from $2500 to $16 000 for an average size new home.
Most insurance companies consider home sprinkler system to be a fire protective device. However insurance discount savings only average 3.42% of annual premium or about $22 average discount savings per year.
The good news is that insurance companies do not charge any penalty or fee to cover risk of accidental water leakage from the system.
In the movies when one sprinkler goes off, all the sprinklers goes off simultaneously. That is not the case in the real world.
Only the sprinkler above a fire will go off minimizing the water damage in the house to an average cost of under $2000.00

Final word…
Sprinkler systems do save lives. It is estimated that about one life will be saved per 100 000 houses fitted with sprinklers. How much is a life worth?
Sprinklers are the fastest effective method of controlling and possibly extinguishing a home fire immediately upon detection, thus minimizing toxic smoke and fatal gases from killing the occupants.
It is hoped that the cost of home sprinkler systems will decrease as the installation of home fire protection grows.

By Cyril Courtois (RCM CAD Design Drafting ltd.)
www.loghomedesign.ca

Topic: Why should you seriously consider building a log home.
Those of us who have had a chance to live in a log home describe the experience as one of security and serenity.
The massive log walls surrounding us muffle the exterior noises and make us feel calm. More than any other type of construction, a log home is a healthy sanctuary, exuding strength and stability, protecting us from nature’s extremes.
Unlike steel, concrete, glass, vinyl and drywall so common in today’s homes, wood feels good to touch. Wood is the noble material of our ancestors. Its colors and textures are soothing to our soul. Its unique character and endless beauty is one of nature’s most fascinating masterpieces…

Basic terminology:
1-The carbon footprint of a building material is defined by the amount of carbon dioxide (CO2) that is released in the earth atmosphere to manufacture, transport and use a product to build your home for example.
2-Global warming (Wikipedia definition) is the increase in the average temperature of Earth’s near surface air and oceans since the mid 20th century and its projected continuation.
3- The main Greenhouse gases (GHG) are carbon dioxide, methane, nitrous oxide, ozone…

1- Log and timber homes carbon footprint:
   Why building a log/timber home may be the most environmentally sound decision you could make to fight global warming…if you believe CO2 emissions play a large role in global warming of the Earth.

In the United States, the construction and manufacturing of building products account for close to 40% of the total CO2 emissions, largely because of USA’s heavy reliance on concrete and steel.
  For comparison, in Finland that number is 5% as wood is a major building material in that country.
A newly released Finnish study (2009) on the environmental impact of construction in that country concludes that using wood whenever possible would further reduce existing CO2 emissions from the building industry by another 25% which would be more than the currently proposed improvements to the energy efficiency of buildings in Finland.

A milestone report prepared in 2006 by the Edinburg centre for carbon management states, that the production of cement and steel accounts for over 10% of global annual greenhouse gas emission (GHG). That percentage includes GHG associated with extraction, refining, manufacture, processing and delivery of cement and steel. The following study shows that if the usual building materials used in Scotland were replaced by wood whenever possible, the carbon footprint of new buildings would be reduced by an average of 81%!!! Because wood has a negative carbon footprint as long as wood is taken from sustainably managed forests.

Wikipedia definition: Sustainable forest management (SFM) in simple terms is defined as achieving a balance between society’s increasing demand for forest products and the preservation of forest health and diversity.

Wood comes from trees. Trees absorb the CO2 from the air to extract the carbon it needs for its structure to about half its dry weight by using the sun energy, water from rain and some nutrients from the soil. In this natural process called photosynthesis it releases oxygen back in the atmosphere.
  Trees are a carbon sink. Carbon is stored rather than being emitted during the production of wood “the Alpha building material”.
It is estimated that approximately 3.5 billion metric tons of carbon is stored in wood construction today in the USA.
That is a lot of carbon stored away from the atmosphere!
So much more could be done to store more carbon in our buildings by using as much wood as possible.
To compare building materials carbon footprint, here are figures released by University of Victoria New Zealand
2003 Center for building performance research
CO2 emissions for a selection of common building materials…in KG of CO2 per cubic meter of material.
Timber= - 690 (negative value)
Concrete=+ 376 
Steel = + 9749 
Aluminum= + 21600

On average trees absorbs 1 metric ton of CO2 for every cubic meter of wood growth! 
When the trees mature the absorption of CO2 slows down.
Harvesting mature trees and replanting maximizes a forest carbon sink potential.
Using more wood in construction increases the demand for sustainable forests, increases the need for new forest plantation and provides a renewable source of carbon neutral energy.

According to Robert Chambers excellent book “log construction manual”, the carbon emission value of wood used for handcrafted log home manufacturing is even better for the environment as it takes only about 200 liters (53 gallons) of fuel to produce a 2000sqft log home shell from raw trees, Robert also states that it takes about the same amount of wood to build a 15″ mid span diameter handcrafted log shell as it takes to building the same house with conventional frame dimensional lumber.
To produce a volume of frame lumber, Sawmills produce more volume of waste (when sawing and surfacing the trees to lumber shape and size). However about 60 % of that waste on average is used as energy to run the mill.

To conclude this chapter, log home construction is arguably the most energy efficient building practice available to us, with the lowest carbon footprint compared to using any other building material available.

2- Longevity of log homes
Log homes are a great investment for many future generations to come. They have proven time and again to last centuries. 
In the USA, the oldest still standing log home was built in 1800 with dovetail corner joinery in Perry county Kentucky.
In Europe, many examples of Scandinavian style log homes dating from 1200s to the 1500s are still lived in.
In Sweden about 150 log homes have recently been carbon dated to the middle ages when Vikings were the rulers of the land. 
Many of those remaining log homes were built on above ground stone basement and have very large single gable roof overhangs that protected the logs from rain and snow…

3- Log homes and your health
In North America we spend close to 90% of our time indoor.
It should make sense that we scrutinize the materials we use to build our homes where we and our children spend so much time. Indoor pollutants are a great concern to health experts in Europe and North America.
The US Environmental Protection Agency (EPA) has identified indoor pollution as one of the top health risk we face every day of our life.
Exposure to indoor pollutants is one of the main reasons for respiratory health problems and cancer for millions of our children.
We assume that building products must be safe, and if we can buy them, then they must have been tested by some government agency. That assumption is completely wrong. 
To make our homes more energy efficient, we live in airtight plastic bubbles breathing air loaded with chemicals coming from our carpets, vinyl, insulations, paints…
Volatile organic compounds (VOCs) are emitted by a wide range of man made chemical building materials we use today in our homes.
A ground breaking book written by architect Paula Baker-Laporte “Prescriptions for a healthy house” goes in great details on this subject.
I highly recommend that all future new home owners read it.

Log homes are made from wood that is 100% natural and does not emit VOCs. Solid wood is the only building material that is recyclable, biodegradable, energy efficient and healthy for your family and the environment.

4- Conclusion to this newsletter:
We are going in the right direction…
In the USA alone, forests have expanded by 25% since 1975.
Green building construction is increasing rapidly all over North America. 
Designers and architects are enthusiastically responding to the green challenge. It is sociably trendy to be green and talk sustainability and loudly promote “green products” of all kinds. To the point where so many supposed green products in the construction industry make very dubious and false claims. 
Consumers are starting to feel apathetic and suspicious towards green claims and I am one of them. 
Greenwashing is a term used to describe marketing products with a green claim that upon some scrutiny shows no proof, is irrelevant, comes with hidden trade off or lesser than two evils arguments.

Among all this confusion, wood, as a building material, is emerging as the answer to fighting global warming in the construction industry all over the world.
Sustainable forestry practices must be quickly expanded worldwide and new forests planted to answer the projected increasing demand for wood in construction and at the same time naturally extract the excess CO2 from our atmosphere.

Log and timber construction is one of the great answers to save our planet.