Green Building and Panelization Responsible Value Delivered
As green building is becoming more mainstream and is recognized as an amenity by home buyers, it is becoming easier for builders to go green. Panel producers are in a position to provide a green product at little or no increased cost to the builder. Panel producers are going green in the factory through two main areas - green products integrated into the final panels and their own green-oriented factory processes. In selecting the raw materials to be used in panel construction, panel producers can easily select green suppliers for most of their requirements.
- Framing lumber - Lumber can be sourced from mills that are certified by either Forest Stewardship Council (FSC) or the Sustainable Forestry Initiative (SFI). This ensures that the mill and its suppliers "integrate the perpetual growing and harvesting of trees with the protection of wildlife, plants, soil, water and air quality."
- Engineered lumber - Through increased use of engineered lumber, not only can panelized firms deliver increased quality (see my last column on kiln-dried and engineered lumber in the October issue), engineered lumber uses smaller diameter and recycled material that in past times may have gone into a landfill. Engineered lumber also reduces the need for large diameter trees to yield 4x or 6x headers and beams (replaced by glulams or TimberStrand/LSLs), as well as for 2x12 floor joists (replaced by I joists).
- Oriented strand board (OSB) sheathing - Through the use of OSB in wall and roof sheathing, an increase in the use of small diameter trees and recycled material is realized without a decrease in performance. PS2 rated OSB is an accepted substitute for APA rated plywood for walls and roofs and delivers the green solution.
- Caulk, sealants and sub-floor adhesives - Low- and no-VOC products are available from many suppliers such as Henkel/OSI and others, in these areas. Though sold at a small premium, there is no degradation in performance and a significant improvement in "in factory" VOCs.
- Zinc-borate LSL sill plate - Through the use of engineered LSL - zinc borate-treated sill plate in wood to concrete applications - the need for use of hot dipped galvanized anchor bolts, all thread rods, nails and seismic hardware is reduced or eliminated. This removes the need for hot dip galvanizing, a component of the building system that requires a significant environmental impact in the manufacturing process.
Panel producers can deliver green in many ways in their internal processes, including:
- Zero waste - Through optimization software used with framing lumber, to innovative use of sheathing material excess, floor and wall panel producers can reduce the waste generated in producing a structure to less than 3 percent, which is then sold for uses such as horse paddock flooring and other manufacturing processes that use chipped or similar material. This is a significant reduction over the 15 percent to 22 percent waste we see on the job site, which creates a job site hazard and ultimately goes into landfills.
- Kiln-dried (KD) lumber and engineering - Through the use of plumb, square and level products, gaps are reduced or eliminated, providing a much superior building envelope with significantly lower air flow through the structure perimeter.
- Sill and panel joint sealer - With the use of sealing strips between the walls and the raised floor or foundation, as well as between panels as they are placed, the building envelope seal is greatly increased. In combination with the use of KD lumber and engineering, the panel producers in Europe have been able to achieve a standard of zero air penetration at a 50 mph wind.
- Sawdust capture and recycle - Sawdust generated in the production process can be captured and recycled as well, eliminating landfill space as well as airborne particulates.
- Packaging - The wood used to protect the panel packages in transit can be used for backing and the in-fill frame portion of the construction process, eliminating the need and cost of sending packaging waste to landfills. Working with a responsible panel producer allows the builder to represent to the city or county that they are committed to the community and the environment, without increasing costs! The smart builder will also integrate the green approach into their marketing material presented to the home buyer.
December 2006 Builder Architect Edition Issue