Single Family Passive House, Calgary, Alberta

Montgomery_SE-view-from-back

Project Overview

This Passive House with secondary suite is nearing completion after 2 years of design and construction.  It is one of the first Passive House projects in Calgary.  The owners, both engineers, took the Passive House Designer Course and have done much of the design and build themselves.  The lot was chosen with Passive House in mind, and has excellent south exposure (this can be hard to find on residential lots in Calgary).

The basement slab and walls are wrapped in 8” of EPS foam.  The concrete floor and walls were left exposed on the inside to maximize access to the thermal mass.  For the main level and loft, a 2×6 wall with additional exterior rock wool insulation was chosen to more closely resemble conventional wall construction.  This was done to make it easier to get permits, pass city inspections, and find a framer.  Two separate Zehnder ComfoAir ERVs provide ventilation to the suite and upper levels.  A natural gas instantaneous hot water tank provides domestic hot water and feeds hydronic coils in the supply air streams for additional space heating.  Klearwall Passive House Certified windows are used throughout.

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The simple geometry and bold colours were inspired by homes in Iceland.  A metal roof was chosen for durability and to reduce contamination of water collected for irrigation.  The small building footprint relative to the lot size maximizes the space left for a food forest and annual garden.

Construction completion is expected by early summer 2016.

Annual Heating Cost

$61 / yr*

* 3070 kWh per year at 2.0 cents/kWh ($6/GJ) Alberta residential rate, with no night setback

See Building Performance Data

Item Quantity
Gross Floor area 2756 ft2
Treated Floor Area (PHPP) 256 m2
Total Annual Heating demand 3070 kWh
Specific Annual Heating Demand 12 kWh/m2
Design Heating Load 3072 Watts
Specific Heating Load 12 W/m2
Heating fuel Gas
Heating Fuel Cost $0.02/kWh ($6/GJ)
Annual Heating cost calculation 3070 * 0.02 = $61 / year
Annual cooling demand 30 kWh/y
Annual cooling cost N/A
Airtightness (calculation assumption) 0.48 ach @ 50 Pa

See Construction Details

Construction Specs Construction Type U-value (R-value) Manufacturer, Location
Floor slab Super-insulated 40PSI EPS Raft Slab 0.157 W/m2K (R-37) Polyfab
Wall structure below grade Exterior EPS Insulated Concrete 0.156 W/m2K (R-36) Quicktherm
Wall structure above grade 2x6 Stud with Service Cavity and Exterior Roxul 0.130 W/m2K (R-45) Siga, Roxul
Roof structure I-beam with Service Cavity, 16in deep @ 24"o.c. 0.097 W/m2K (R-60) Siga
Wall Insulation Roxul Comfobatt and Dual Density Cavity Rock 290mm Roxul
Roof Insulation Fiberglass Insulation 400mm Owens Corning
Windows Klearwall Future Proof Klearwall, Ireland
Exterior Door Klearwall Future Proof Klearwall, Ireland
Window Frame (Uf) Klearwall Future Proof 0.66 W/m2K Klearwall, Ireland
Window Glazing south (Ug) triple high SHG 0.6 W/m2K Saint-Gobain
Glazing SHGC (g-value) south triple high SHG 0.61 Saint-Gobain
Window Glazing North (Ug) triple high SHG 0.5 W/m2K Saint-Gobain
Glazing SHGC (g-value) north triple high SHG 0.49 Saint-Gobain
Airtightness 0.48 ach @ 50 Pa (first test)
Ventilation system Zehnder/ Comfoair 200 and 550 (ERVs) 92% & 84% efficiency Zehnder
Hot Water Gas-Fired, Instantaneous, Condensing Hot Water Tank
Heating System Glycol-Air Post ERV Heating w/ Electric Baseboard Backup

See Design & Construction Team

Role Person Location email
Architect LV Design/ Elizabeth Valentine, AAA Calgary, AB liza@lvdesign.ca
Passive House Designer Frank Crawford and Melissa Valgardson Calgary, AB frank.crawford@outlook.com, mvalgardson@gmail.com
Builder Frank Crawford Calgary, AB frank.crawford@outlook.com
Building Envelope Supplier Ardco Construction Irricana, AB ardentconstruct@gmail.com
PHI-Accredited Certifier NA NA