“This was the easiest project I’ve ever certified” - Tad Everhart, PHI-accredited Certifier, CertiPHIers, Portland, OR

Valemount Passivhus (Passive House in Swedish), Valemount, BC. Status:  Unconditional Occupancy. Siu Architecture Inc. delivered the architectural schematic design and structural concept for this Passivhaus Institut certified Passive House Classic under the lead of Erik Olofsson Construction and in colloboration with Collective Carpentry and Kim Walton CPHC, Bow Crow Design. Tad Everhart CPHC, CertiPHIers Cooperative acted as the third party certifier. Photo and video credits: Andru McCracken, Erik Oloffson and Rane Wardwell (Collective Carpentry). The clients’ intent to pursue Passive House certification is to showcase Valemount as a growing community responsible to the beautiful surroundings of the Rocky Mountains including Mt. Robson and Mt. Trudeau, the latter of which is framed by the family room window of the upper floor. Faced with an extremely low budget, the strategy of the design maximizes the efficiency of the structure with only exterior walls bearing load on perimeter grade beams and supporting a clear span pitched roof allowing flexibility of interior partitions. Exterior walls and roof were pre-fabricated and shipped to the site and framed within two days. While more expensive than on-site framing, pre-fab and modular construction is a solution to declining productivity of the construction industry in BC where R&D intensity is less than 1%. The pure rectangular plan and minimalist gable form is conducive to Passive House PHPP energy modeling of the design and testing of constructed building for performance criteria including air tightness while also making reference to early Scandinavian vernacular barn houses. Local cedar siding was torched on site to achieve a charred surface resistant to weather, UV and pests. Prefabricated wall and roof assemblies consisted of a 14-16” I-joist framed insulation mass of blown in cellulose outriggered off 2×4 load bearing studs down to a grade beam foundation and slab on grade wrapped in salvaged EPS achieving the following R-values: wall @ R-59, roof @ R-73 and slab on grade @ R-88. The project is certified as a Passive House Classic by the Passivhaus Institut in Darmstadt with the following third party evaluated performance criteria: Heating demand: 15kWh/(m2a), Heating load: 13 W/m2 , Frequency of overheating: 1%, Frequency of excessively high humidity: 0%, PE demand: 111kWh/(m2a)