The New Old Barn project shows how modern energy-efficient building methods can be combined with the sustainable practice of reusing historic timber frames instead of cutting new wood. We managed all phases of this project, from clearing the lot and building the foundation to installing the necessary drainage and septic systems. The house combines historic, rural charm with state-of-the-art green building methods, including energy-efficient structural insulated panels, or SIPs.
Our client has a wooded lot with a small guest house that he wished to expand into a studio space using sustainable and green construction practices. He reclaimed the timber frames from an 1850s barn which had been disassembled. Before we were able to create a new building with the reclaimed timbers, we had to do some clearing and excavation on the lot, and then we built a foundation for the new structure.
The reclaimed timber frames were solid, but modern building codes are tougher than they were a century or more ago. We gave the building the necessary structural support by installing a tongue and groove roof deck and SIPs (structural integrated panels) for the walls. In addition to the structural considerations for the building met standards, we also ensured that the site’s drainage and septic systems were up to snuff.
SIPs are prefabricated wall panels that sandwich insulating foam between two layers of wafer board, what we call in the industry oriented strand board (boards created from waste wood material reclaimed at lumber mills), or just OSB. The panels make a building that is incredibly energy efficient, because SIPs fit together very tightly; this means that solid carpentry experience and some special training is needed to build with them. Special methods must be used when installing wiring, heating and air condition systems in the panels. The crane operator and crew work in tandem to precisely place each SIP.
There is little room for error when cutting SIPs to the right size, because they fit together very tightly; this improves heating efficiency while reducing the flow of air and moisture and in out of the building. The tight fit is why we could use them to make the New Old Barn more sound than the reclaimed timber frames would be on their own, but it also means that air and moisture don’t move freely through them. We installed a special heat-recovery exchange unit so that the New Old Barn’s owner won’t ever have problems with excessive moisture in his studio.
The cost savings from using SIPs in construction are surprisingly good. In the article “SIPS: Are They Right for Your Next Project?” (Fine Homebuilding, June/July 2007), editor John Ross looks at a 2005 homebuilding project as an example. The West Virginia homebuilding project cost just 6% more up front, but the energy savings and tax rebates had the owners breaking even in two and a half years. The efficiency of these homes demands a smaller, less expensive system for heating and cooling, which contributes to the lower building costs.