Wallingford Passive House Residence
Building Use: Detached single-family residence
Project Type: New passive house building
This new single-family house replaced a small, old building on a small neighborhood lot with a relatively limited buildable area relative to the space and functions that were needed. The house is set back from the street as far as possible, allowing for a basement garage with the steepest permissible driveway, a partially heated basement, and three stories above. Some notable features are a residential elevator, fully within the thermal envelope, roof decks, and 'moats' at the front and rear patios that allow finish grade to be flush with the interior floor, with the floor framing still bearing fully on the foundation wall.
| Location: | Seattle, Washington 98103 | |
| Dwelling Units: | 1 | |
| PH Calculation Protocol(s): | PHI | |
| PH Modeling Software(s): | PHPP | |
| PH Certification(s): | PHIUS | |
| Year Of Construction: | 2016 | |
Project Size | ||
| Floor Area: | 3,458.4 ft2TFA | 321.3 m2TFA |
Performance | ||
| Annual heat demand: | 4.24 kBtu/yr•ft2TFA | 13.4 kWh/yr•m2TFA |
| Heat load: | 3.30 Btu/hr•ft2TFA | 10.4 W/m2TFA |
| Primary energy demand: | 28.10 kBtu/yr•ft2TFA | 88.6 kWh/yr•m2TFA |
| Primary energy demand after on-site generation: | 21.30 kBtu/yr•ft2TFA | 67.2 kWh/yr•m2TFA |
| Airtightness: | 0.34 ACH50 | |
Envelope | ||
| Construction Type: | wood | |
| Floor Assembly: | Basement floor (R: 34.6 h•ft2•°F/Btu): • concrete slab • air & vapor barrier membrane, • 8" EPS insulation Floor over unheated garage (R: 52.0 h•ft2•°F/Btu): • finish flooring (tile / wood) • plywood subfloor • 14" TJI joists with high-density blown-in fiberglass insulation • 5/8" drywall | |
| Wall Assembly: | Below grade (R: 39.6 hr•ft2•F/Btu): • drywall • 2x4 wood studs with high-density blown-in fiberglass insulation • 6" EPS insulation • concrete foundation wall (air barrier) Above grade (R-38.1 h•ft2•°F/Btu): • 5/8" drywall • 2x8 wood studs with high-density blown-in fiberglass insulation • ZIP sheathing OSB (air & weather barrier) • 3" Roxul rockwool panels • vertical furring with fiber-cement panel cladding | |
| Roof Assembly: | Lower roofs (R: 76.2 hr•ft2•°F/Btu): • 5/8" drywall • 14" TJI rafters with high-density blown-in fiberglass insulation • plywood sheathing (air-barrier) • 2x8 overframing at overhangs, 7 1/4" EPS / Roxul insulation • 2x furring for venting cavity • plywood • TPO roofing membrane Upper roof (R: 49.0 hr•ft2•°F/Btu): • 5/8 drywall • furring for installation cavity • OSB air barrier • 16" wood trusses with 14 .5" high-density blown-in fiberglass insulation • 1.5" venting cavity • plywood sheathing • standing seam metal roofing | |
| Windows: | Unilux DesignLine 0.7 | |
| Entry Doors: | Unilux wood entry door | |
Systems | ||
| Ventilation system: | Zehnder ComfoAir 550 | |
| Heating/Cooling system: | Mitsubishi mini-split heat pump with two ducted indoor units | |
| Domestic hot water system: | Navien 240, natural gas fired, tankless water heater | |
| Renewables: | 3.3 kW roof-mounted photovoltaic system with projected generation of 3,459 kWh/yr | |
Team | ||
| Passive House Consultant: | Markus Barrera-Kolb | |
| Passive House Consultant Certification: | PHIUS | |
| Architect: | Whitney Architecture | |
| Structural Engineer: | Bykonen Carter Quinn | |
| Contractor: | Hammer and Hand | |
Comments | ||
| Additional Information: | PHPP model used internal heat gain per the PHIUS protocol. | |