Urban Green Duplex
Urban Green Duplex

Project Specs

Location: Victoria, British Columbia
Building Type: Multi-Unit Residential
Project Phase: Certified
Certification Type: Passive House Classic
Year of Construction: 2016
Gross Floor Area (m2): 280
PHPP Verification: Download

Project Description

This new Passive House modeled duplex was designed by Cascadia Architects. True to the Passive House design, it has a highly efficient and controlled interior environment that dramatically reduces the homes energy consumption, and increases comfort and health for the inhabitants.

The entire building was modeled inside the Passive House energy software down to the last detail. The passive solar heat gains, through precisely placed windows provide the majority of the buildings heat. Carefully calculated overhangs, and window location and size limit overheating in the summer months. The building is air-tight to stop unconditioned air from infiltrating the building envelope, with the interior fresh air exchanges controlled by an HRV unit. Additional insulation and special high-efficiency windows were installed to slow heat loss. Thermal bridging of every structural component was calculated and detailed to reduce energy transfer.

We were able to reclaim some of the old fir flooring from the previous building. After resurfacing it, we created some custom millwork around the kitchen island. The main level floors are polished concrete, and the upstairs flooring is maple. Smart choices on the finishes resulted in good economy with an incredible modern look and feel.


Thermal Envelope

Exterior Wall: 13 mm gypsum board
R14 Batt insulation
38 mm x 89 mm @ 400 mm wood studs
13 mm plywood sheathing
Siga Majvest weather barrier
150 mm Roxul CavityRock insulation w/ z-grit clips
38 mm x 89 mm horizontal strapping
19 mm cedar siding
U-value = 0.156 W/(m2K)
Basement Floor/Floor Slab: 38 mm concrete top coat
25 mm XPS insulation
19 mm plywood sheathing
300 mm TJI @ 400 mm floor joists
R40 batt insulation

U-value = 0.128 W/(m2K)
Roof: 13 mm gypsum board
38 mm x 89 mm @ 400 mm drop ceiling joists
R14 batt insulation
13 mm OSB sheathing
406 mm @ 400 mm trusses
2 layer R28 batt insulation
13 mm plywood sheathing
Torch-on roofing membrane
U-value = 0.11 W/(m2K)
Window: SGG PLANITHERM ULTRA N (4:/16/4/16/:4 Ar 90%)
U g-value = 0.63 W/(m2K)
g -value = 55 %

Mechanical System

Ventilation: Zehnder, ComfoAir 350
Whole system efficiency (PHPP): 77%
Electrical efficiency: 0.29 Wh/m3
Decentralized ventilation system. Each dwelling is served by it's own unit.
Bedrooms and living rooms are supply zones. Kitchens, bathrooms, and laundry rooms are exhaust rooms. All other floor spaces are transfer zones.
Heating/Cooling: Electric resistance heating utilized. Each upper floor bathroom has electronically heated floors. Each living room has a wall-mounted electric convection heater.
Domestic Hot Water: Rheem Marathon water heaters installed, one per dwelling.