Case Study

Vital Stats Location: Seattle Star Level: 5-Star Checklist: Single Family/Townhome Verifier: Tadashi Shiga, Evergreen Certified Section Points Site and Water 132 Energy Efficiency 174 Indoor Air Quality 131 Material Efficiency 97 House Size Multiplier 1.0 Total Score 585

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Dwell Development– Seattle, WA
Project: Rainier Vista micro-community

This four-home micro-community in Seattle’s Rainier Vista neighborhood is a great example of 5-Star green building and design at an accessible price point. The units range from 1,350 to 1,850 square feet and are part of a site that will ultimately be built out to 15 units, including aging in place units, affordable housing and potentially some net-zero energy units. These first four include rain barrels, rooftop gardens, heat recovery ventilators, triple pane windows, whole home radiant systems, pine flooring recycled from telephone poles, recycled glass countertops and factory framed wall panels to reduce waste. The units are close to the light rail, as well as the numerous amenities of the Columbia City neighborhood, and represent an outstanding combination of green design and building science that result in beautiful homes.

Some of the many green features of the project include:

Site and Water Protection

• Built on an infill lot, close to light rail and Columbia City business district
• No turf grass installed
• Exclusively landscaped with drought tolerant and donated plants
• Provided infiltration for rooftop runoff, including rain barrels and planter boxes
• Installed mall roof-top gardens
• Installed dual-flush toilets in all units
• Installed low-flow showerheads, kitchen and bathroom faucets to reduce water and energy use

Energy Efficiency

• Modeled homes to achieve 40 percent improvement over 2009 Washington State Energy Code
• Scored a HERS rating of 53
• Incorporated factory-panelized double-wall construction with high density fiberglass insulation resulting in R-43 walls
• Installed triple pane windows to achieve average U-value of 0.22
• Achived blower-door test leakage of only 1.5 ACH50
• Installed R-20 expanded polystyrene insulation beneath full slab
• Installed whole home radiant system with 98-percent efficient self-condensing boiler
• Wrapped all electrical outlets with putty packs to reduce thermal bridging
• Installed Energy Star refrigerator, dishwasher and washing machine in all homes
• Installed electrical conduits for future photovoltaic use

Indoor Air Quality

• Installed heat recovery ventilator (HRV) as whole house fan with MERV 12 filter
• Installed dimpled drainage mats for moisture management along with R-10 rigid foam
• Used low-VOC paint for all interior surface areas
• Used low-VOC, low-toxic water-based sealants and adhesives for tiling, framing, insulating and drywalling
• Installed sloped sill pans with end dams and back dams for all windows
• Installed sill protection at windows and doors

Material Use

• Achieved overall recycling rate of 90 percent
• Installed reclaimed pine flooring which was re-milled from old telephone poles
• Install recycled glass Novustone countertops
• Used panelized wall construction for framing to conserve materials
• Installed metal roofs on homes
• No use of vinyl on siding, flooring or trim

Still Images

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Photos courtesy of Tucker English Photography.

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