INNOVATION November-December 2016

that of typical homes in Fort St. John.The house consumes about 90 percent less heating and cooling energy than a typical code-built house due to the energy-efficient building envelope. Heating/cooling costs totalled about $600 this year, a savings of up to $2,000 compared to houses built to provincial building code standards in this climate. With air-source heat pumps and backup electric baseboard heat, the house emits about 0.05 tonnes of greenhouse gases per year—a 99 percent reduction relative to a typical single- (AHC) @ 50 Pa (total air leak is equal to a 10-cm hole), compared to an average Canadian home built in the 2000s, at 3–4 ACH @ 50 Pa (equal to a 60-cm-diameter hole). • An EnerGuide rating of 91. • Net-zero energy ready. • An R-value of 56, compared to the average house’s R-value of 22. • Certification as a Passive House Plus (PH+) through the Passive House Institute US. • Certifiability as LEED Platinum. (The LEED application is pending.) family detached dwelling in the region. The house achieves other key results: • Airtightness of 0.33 air changes per hour

Passive House Standard Gains Ground in BC The passive house standard is a rigorous, voluntary energy-efficiency standard for buildings. Despite its name, it can be applied to any type of building. Of the 35 passive-house buildings currently listed on the global Passive House database as certified, with applications for certification, in construction, or planned, 20 are located in BC. One is a recreation centre. Several are apartment or condominium buildings ( S hown : the N orth P ark P assive H ouse M ulti - family R esidence , V ictoria , BC. P hoto : P rovince of BC cc by - nc - nd 2.0). The others are detached or semi- detached single-family homes. The Fort St. John Passive House was certified by the Passive House Institute US. For a building to be certified as a passive house, it must meet specific criteria. Its annual space-heating or -cooling demand must be 15 kWh/m²a or lower, or its peak heating load must be 10 W/m² or lower. Its pressurisation test results must be no more than 0.6 times the building volume per hour (both over- pressure and under-pressure) at 50 Pa. In addition, the total annual primary energy consumption must less than 120 kWh/m²a. A passive house includes a number of components that, together, act to maintain indoor air quality and circulation and consistent indoor temperature while minimising heat loss. These include efficient building shape, solar exposure, advanced windows, airtightness, ventilation with heat recovery, thermal bridge-free building envelopes and, in Canada, superinsulation that covers the entire building shell. Although it is more efficient and cost effective to build the standard into new construction, the Canadian Passive House Institute says retrofits are possible, depending on a building’s state, shape, size and age. In this issue, Innovation explores two tall- building retrofits that yield significant energy savings ( S ee pages 24 and 34 ). — Monique Keiran

31

N OV E M B E R /D E C E M B E R 2 016

i n n o v a t i o n