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|Vital Stats |
|Location: Seattle |
|Star Level: 4-Star |
|Checklist: Single Family |
|Verifier: Tadashi Shiga, |
|Section ||Points |
|Site and Water ||54 |
|Energy Efficiency ||72 |
|Indoor Air Quality ||58 |
|Material Efficiency ||82 |
|House Size Multiplier ||1.05 |
|Total Score ||279.3 |
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Case study written by Camron Momyer, Project Coordinator, Evergreen Certified
This 3-bedroom, 2.5-bath home by R. Thoreson is nestled into the cozy South Seattle neighborhood of Mt. Baker. Just 500 feet from the local coffee shop and within easy walking distance of schools, parks and the beach, this green home should get extra credit points for location. While it blends well with the older, more traditional homes in Mt. Baker, its high performance systems are anything but traditional.
Most notable among the new features, a heat recovery ventilator (HRV) adds to this well-sealed and insulated homes green merits. HRV's become increasingly important for indoor air quality the more airtight a structure becomes. As the HRV flushes indoor air out through the system, it exchanges the temperature of the indoor air with the fresh, filtered air coming from the outside. An HRV means that an airtight home no longer has to sacrifice indoor air quality and that a well- ventilated home no longer has to sacrifice on heating and cooling bills.
Site and water
Dual-flush toilets and EPA WaterSense fixtures grace every bathroom. A storm-water retention tank in the side yard helps to mitigate runoff from the roof and the water savvy landscape makes use of plants that do well in the Northwest without a lot of extra water. In addition, compost and a deep layer of mulch help the soil retain moisture.
Blown-in recycled content and formaldehyde-free insulation were used to bring the walls to a true R-23. An on-demand Noritz hot water heater provides both the domestic hot water and space heating. The two main floors make use of hydronic radiant heat while the basement uses a hydronic wall fan. Due to the high efficiency heating system combined with great insulation and an HRV, energy models show this home is 25-percent more efficient than Washington state code requires.
Indoor air quality
Indoor air quality was addressed through material selection and a focus on limiting toxins in the interior. Ceramic tile, pre-finished wood flooring, hydronic heating and limited use of carpet all help to limit the amount of dust in the home. Low-VOC paints, formaldehyde-free insulation and ventilation after application of new finishes helped limit chemicals in the home. Finally, the HRV ensures good airflow and low humidity, which will help prevent the development of mold.
Care was taken to choose materials with longer life cycles, such as Hardie Board siding, cedar planks and shingles with a 30-year lifespan. Trim and millwork were all sourced locally and are free of added urea formaldehyde.
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|Photos courtesy of Ted Evans |