As modular construction gains attention as a means of accelerating housing delivery, CSA Group has released a new standard for the design of volumetric modular buildings.

CSA Group has released a new framework that provides a common technical basis for the design of volumetric modular buildings—structures manufactured off-site as modules and assembled on-site. CSA Z251, Design of volumetric modular structures, is a new National Standard of Canada.

Developed to complement the National Building Code of Canada (NBCC), CSA Z251 sets out requirements for modular design, including structural performance, building services, environmental separation, fire protection, manufacturing, and architectural considerations.

CSA Group says the standard was developed by a technical committee that included architects, engineers, modular manufacturers, and provincial and municipal building officials, with input from across the sector.

The standard arrives as modular construction gains prominence in national housing policy. The federal government has identified it as one of the modern methods that could help deliver housing at scale through Build Canada Homes. According to CSA Group, the modular construction industry is valued at more than $5.5 billion and is projected to grow by more than five per cent annually through 2029.

Consistent approach

“Modular construction has the potential to help Canada deliver housing and infrastructure faster, but scaling the sector requires a consistent approach to how buildings are designed,” says Dwayne Torrey, director, construction and infrastructure standards at CSA Group. “CSA Z251 provides that common framework, giving architects, engineers, manufacturers, and building officials working in volumetric modular design.”

Tom Hardiman, executive director of the Modular Building Institute, says the standard addresses a gap that has limited broader adoption of modular construction. “Standards like CSA Z251 provide the consistency and clarity needed to scale modular construction and give confidence to the companies and communities investing in it,” he adds.

CSA Group develops standards, codes, and related products for a range of sectors.