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RCAC Self-Help Builder News December 2011 Volume 4, Issue 4 >
Green building: Housing Kitsap
By Art Seavey, RCAC rural development specialist
For the past three years, Kitsap County Consolidated Housing Authority (dba Housing Kitsap) has been dedicated to the implementation of green and sustainable building features in its mutual self-help homes. Housing Kitsap’s single family housing director, Casey Pleskun, and construction manager, Dean Nail, became accredited sustainable building advisors. As a result, they are able to perform blower door tests and continually strive to evaluate and upgrade Housing Kitsap’s home plans while keeping costs as close to their original budgets as feasible. They seek technical assistance and work closely with RCAC and other sources to achieve the greatest energy efficiency within their modest budgets.
To achieve their green goals, they made their house plans smaller, eliminating non-essential areas to achieve cost reduction. Additionally, they use advanced framing techniques with studs 24” O.C. This eliminates thermal bridges and a reduced number of studs, using only a single top plate with trusses stacked on top of studs.
Housing Kitsap receives pre-cut lumber packages from a supplier, who uses a computer-run optimizer process to select and cuts all material to greatly minimize waste. In addition, the plates are laser etched with stud and partition layouts—doing away with the need for a supervisor to perform the layout, freeing them to perform other tasks. This saves construction time, as well as dumpster costs and dump fees, while maintaining good quality. Housing Kitsap also uses 30 percent fly ash in all the concrete pours.
When natural gas is available, Housing Kitsap has elected to install an on-demand (tankless) condensing boiler, which supplies hot water. An added unit sends the hot water through a radiant floor heating system.
When gas is not available, they install a Mitsubishi mini-split ductless heat pump to provide both space heating and cooling as needed. These are highly efficient systems with a SEER of 23 and a HSPF of 10.5.
Housing Kitsap uses high performance double paned windows with a .30 U-value and low E with argon filled cavity. Housing Kitsap uses closed-cell spray foam to line the stud cavity, ensuring a good seal between the studs and sheathing, that is then filled with a dry cellulose fill to achieve an R23-R25 wall rating. The trusses used incorporate a raised heel, which allows for an even insulation thickness over the top plate and throughout the attic achieving an R-49 rating.
Housing Kitsap’s homes are sealed tight and ventilated right with a whisper quiet whole house fan. The fan operates continually only drawing 4 watts, and is fitted with a motion sensor that improves indoor air quality. They use Energy Star appliances and lighting fixtures.
Low-flow water fixtures are used with dual flush toilets (.8 gpm/1.3 gpm), showerheads (2.0 gpm), bathroom faucets (1.5 gpm) and kitchen faucets with a 2.0 gpm flow.
All homes are inspected and confirmed by a third party home energy rater, and are sent to Washington State University (a state certifying organization) for Northwest Energy Star certification at the tax credit level. The homes must achieve no greater than four air changes per hour to qualify. Housing Kitsap has managed to average 2.7 air changes per hour.
Housing Kitsap has performed a study of three previously built homes with three currently built homes, and has seen a utility cost savings of 40-50 percent!
Housing Kitsap will continue to evaluate new energy efficiency technology to determine its fit with their program and budget. And, this grantee will continue to work with RCAC to evaluate cost-saving and energy efficiency developments.