Page 22


BC Passive House Factory, Pemberton, British Columbia, Canada BC Passive House is a manufacturing company that prefabricates passive timber-frame building systems. Completed in the summer of 2014, the company’s new factory is an ‘all wood’ demonstration project designed to exemplify the firm’s commitment to wood design and sustainable construction. The building, designed by Hemsworth Architecture, consists of a large open workspace divided into two distinct bays used for manufacturing, plus a conference room and office mezzanine to the southwest, where 360-degree clerestory windows provide natural daylight and spectacular mountain views.

The mezzanine offices, support spaces and showroom were designed and built to meet the passive house standard, with space heating demand of 14Wh/m2/yr. The building’s envelope was constructed using BC Passive’s wood-based, double wall, super insulated system that is airtight while remaining vapour diffusion open to the exterior. Blown cellulose recycled paper was used for insulation, and while a final airtightness test has yet to be completed, BC Passive House expect a result of around 0.3 air changes per hour. The open workspace has different heating requirements to offices, only needing temperatures of 10-15C. Here, a biomass boiler uses wood waste from manufacturing to deliver heat through an underfloor radiant system. The use of these prefabricated structural components allowed for the building’s superstructure to be set-up onsite in just eight days.

In addition, prefabrication allowed for the construction of the building components in a controlled environment — increasing efficiency, quality control and precision while reducing exposure to weather. The building’s exterior was finished in fir and larch that was left untreated, with the intention that it grey with each passing season. This provides a natural, VOC free, no maintenance solution. Products and materials were chosen for low environmental impact. The conference room was finished with cedar milled from trees salvaged from a 1930s burn site. Plant storage, desks, shelves and staircases were constructed from waste CLT panels, while pumice and recycled foam glass insulation were used for under-slab insulation. Adopting a wood first approach for the structure of the building also avoided approximately 365 metric tons of CO2 emissions, according to the carbon calculator. u

Photos: Ema Peter Photography

This issue’s international selection features a developer-built passive house in Philadelphia, a big new research centre in Frankfurt, a sleek family home in Vienna, and a new low-energy factory in Canada where passive timber buildings will be prefabricated.

Profile for Passive House Plus (Sustainable Building)

Passive house plus issue 11 (UK edition)  

Passive house plus issue 11 (UK edition)