Formula to find out how green you're building
Q. We are in the planning stage of building a new house. I always thought of a standard lumber-framed house as the greenest (best for the environment). Is there a way to make it even greener?
Beth L.
A. One would naturally think a house built with lumber is green because wood is a renewable resource. We see trees everywhere and civilizations have used wood as the basic building material for thousands of years. For the typical American lumber-framed home, up to 1½ acres of forest are consumed for just the structural framing.
In order to determine if the typical lumber-framed building method is indeed green, you must consider the entire life-cycle of the materials used. This includes four factors: the original collecting of the resources, any manufacturing operations on them, the construction process, and finally the disposal of the house after is it demolished sometime in the distant future.
Based upon the above factors, a wood-framed house can be one of he greenest building method if it is done properly. One key is using as little lumber as possible to build the house. Proper initial design and framing methods can dramatically reduce the amount of lumber used. Using less results in less of each of the four factors listed above.
If you have ever driven past a building site where the house framing is finished or nearly finished, you often see a huge dumpster filled with scrap lumber. When building a typical American home, almost two tons of waste lumber is created. Not only did this waste material use energy to produce the lumber initially, but more energy and equipment are consumed to haul this waste away.
Discuss OVE (optimum-value engineering) design principles with your architect and builder. One of the primary recommendations of OVE is to size the home and specific areas within it in increments of two feet. Since lumber is typically available in lengths of eight, 10 and 12 feet, two foot increments divide into this evenly. Even proper sizing of closets and shelving can minimize waste.
Another recommendation for reducing the consumption of lumber is to build the wall framing using 2-by-6 studs on 24-inch centers instead of traditional 2-by-4 studs and 16-inch centers. Applying this design concept can save up to 2,000 board feet of lumber for a 2,000 square-foot house. Another advantage of 2-by-6 construction is it allows for more wall insulation and a savings on utility bills.
Another key for a greener house is using lumber which has been harvested from a sustainable forest. When purchasing lumber for your new house, select lumber with the FSC (Forest Stewardship Council) certification. This organization certifies millions of acres of forests. Many lumber retailers, such as Lowe's and Home Depot, are sources for FSC certified lumber.
Always use the lowest grade of lumber which is suitable for the specific application. Higher-grade lumber will function well in most applications, but it often requires more initial manufacturing operations to produce it and, therefore, more waste.
Steel framing is also an option for some of the areas of the house. Today, the majority of steel used for construction framing is recycled from scrap. It also is strong and can be designed to replace some lumber framing stick-for-stick. When the house is demolished someday, the steel can be recycled and used again in another new house.
Starcott Media Services