BC Standardized Designs Catalogue

In 2024, the Province of British Columbia funded the creation of 10 standardized multiplex design concepts as part of its push to increase housing supply across the province. The designs were produced by a consortium of five firms contracted by the Province, led by Leckie Studio, and released free of charge for anyone to use.

The catalogue includes seven SSMUH (Small-Scale Multi-Unit Housing) designs -- ranging from duplexes to townhouse rows -- and three ADU (Accessory Dwelling Unit) designs for garden suites, laneway houses, and carriage houses.

What makes these designs unique is their mix-and-match building block system. Rather than providing one fixed floor plan, each concept uses a modular approach with stackable 1-, 2-, and 3-storey configurations. This means a single design concept can be adapted to multiple lot widths and depths by mirroring, stacking, or combining blocks.

All 10 designs comply with BC Energy Step Code Step 4 and are engineered for Climate Zone 5, which covers the majority of populated areas in British Columbia.

The cornerstone of the BC catalogue is its modular building block approach. Instead of offering a single rigid floor plan for each housing type, the designers created a set of base units that can be composed in different ways:

• Base Unit -- A core living module (typically one bedroom or one-bedroom-plus-den) with a standardized footprint and structure.
• Stacking -- Base units can be placed on top of each other to create 2- or 3-storey configurations, increasing density without increasing the building footprint.
• Mirroring -- Units can be mirrored along a shared party wall to create side-by-side duplexes, fourplexes, or townhouse rows, making efficient use of lot width.
• Combining -- Different block sizes can be mixed within a single building to offer a variety of unit sizes (e.g., one 2-bedroom and two 1-bedroom units in a triplex).

This system means that a single design concept -- say Quadplex 1 (Fourplex Stacked) -- can be adapted to fit a narrow 33-foot lot as well as a wider 50-foot lot by adjusting the mirroring and stacking configuration. It also simplifies structural engineering because the load paths are standardized across configurations.