Changes in design and construction practices described below can lead to great savings in wood consumption. If the building industry implements the changes in design and construction-site practice outlined here, we estimate an immediate, industry-wide wood-use reduction of at least 30 percent is possible.
Attempts to reduce wood consumption in construction should not be based solely on the wholesale substitution of other standard building products for wood framing. Steel framing and concrete, both energy-intensive to produce, are not necessarily an environmental improvement over wood framing.
One solution lies in using wood wisely. Engineered lumber, for instance, is stronger and more consistent in quality, with less fibre and weight than solid-sawn wood products. As much as 25 percent of timber delivered to a job site may be wasted or culled. Use of engineered timber-components prevents wood waste from cutoffs at job sites. Consistent quality also means that virtually no wood is culled at the job site.
Structural insulated panels faced with OSB (Oriented Strand Board, ie, medium density fibreboard - ed.) elimate the traditional use of dimensional lumber in wall framing.
Houses are getting bigger, even though family sizes are decreasing. Today, there is four times as much surface area per person in housing than there was 40 years ago. In fact, nearly half the homes larger than 3,000 sq feet (280m2) are occupied by couples living alone, according to the US Census. The most obvious means of cutting the consumption of wood and other resources is to build smaller, space-efficient houses. Multi-family housing uses less wood in shared walls 2.
Retrofitting an existing building for energy-efficiency, using resource-efficient materials, consumes far fewer natural resources than creating a new building.
Using engineered trusses instead of stick framing allows a substantial reduction in the amount of timber. Engineered lumber beams also use less wood for roof and floor framing. Wood floor framing can be eliminated altogether when a concrete slab-on-grade floor is used.
House designs that make use of 60cm dimensional increments greatly reduce the amount of waste generated on-site from offcuts. Simple designs allow for less complex framing that requires less wood. Open floorplans that have few interior walls also reduce wood use.
1. See under Architects, Designers, in the Building Section of the Alternative Directory.
2. The 'Australian Light Timber Framing Code' uses 'Advanced Framing Techniques' based on ideas as in the text, above. The Code includes detailed structural tables. Also note that US framing specifications may be up to twice the size of Australian specs.