Bella Bella multi-unit

Modular Passive House construction a pioneering effort

Bella Bella is a small community located on Campbell Island between the northern tip of Vancouver Island and Haida Gwaii. Approximately 90% of its 1,500 residents belong to the Heiltsuk First Nation.

By Peter Treuheit

In 2004, a fire destroyed the staff housing complex at the RW Large Memorial Hospital, and Vancouver Coastal Health [VCH] needed to construct a replacement facility. At the time, VCH was actively considering changing the performance requirements for new facilities from LEED to Passive House. Buildings certified to Passive House require up to 90%  less heating and cooling energy than an average building.

The Bella Bella project was seen as an opportunity to put this change into practice. An RFP was issued for a design/ build contract, including a basic program, design criteria and the requirement for Passive House certification.
Mobius Architecture had been involved in the assessment of the fire damaged structure, and saw the opportunity for an innovative solution to this challenging project. It sought out Spani Developments, a local company that had worked previously for VCH, but also had experience building homes in remote locations.

It quickly became clear that conventional site-built construction would not work, given the short construction season and the need to barge all materials to the site. The team considered prefabricated panel solutions, but these would also have been vulnerable to weather. In addition the complexity and precision required for Passive House certification made site construction, and even panel construction, risky. The team then considered volumetric prefabrication, and approached Britco to see whether the program requirements and specifications could be met in its production facility. They could, and Britco joined the team.

The team realized a significant amount of work would be required to respond to the RFP with drawings and a fixed price. Passive house certification on modular construction had not been attempted in British Columbia before, and the learning curve was steep. Accordingly, we sought out Red Door Energy [and through them] RDH Building Engineering for their expertise in the Passive House methodology and envelope design, respectively. Most important, however, was their ability to train the Britco and Spani workforce who would be responsible for the factory fabrication and site assembly of the project.

Preliminary architectural drawings, details and a product list were completed. At the same time Britco and Spani personnel refined and costed the scope of factory and site work, and Red Door energy worked on Passive House precertification. The logistics of transportation by truck and barge also had to be understood, and the risks and uncertainties mitigated within a fixed price quotation. One significant advantage of the volumetric prefabrication approach was that the modules could be pretested in the factory before being shipped to the site.

MATERIALS

Wood-frame construction with mineral wool and fibreglass insulation and metal cladding built to Passive House standard by Britco Construction; Thermoplus 4700 Series windows by Euroline Windows Inc.; split system heat pumps and Comfoair 200 HRV units by Zehnder.

PROJECT CREDITS
Owner Vancouver Coastal Health Authority
Architect Mobius Architecture Inc.
Structural Engineer CanStruct Engineering Group
Mechanical Engineer ITEC Systems Design Ltd.
Electrical Engineer Opal Engineering
Passive House Consultant Red Door Energy
Building Envelope RDH Building Science Inc.
General Contractor Spani Developments Ltd.
Module Fabricator Britco Construction
Photos Britco Construction

Peter Treuheit is principal with Mobius Architecture Inc., in Sechelt, BC.

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