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.
