Most urban lots in Canada can now take three to eight units. Whether a parcel gets there depends on its ground conditions and the approval path chosen.
In 2025, CMHC launched its Housing Design Catalogue, which included more than 50 standardized designs, from accessory dwellings to fourplexes and six-plexes, in seven regional versions covering every province and territory. B.C.’s own catalogue of standardized designs, released in September 2024, carries the line that matters more than any of the drawings: “minor amendments may be required to manage specific site conditions.” That sentence is where most infill projects in Canada now succeed or stall.
The policy barrier has largely come down. Ontario’s More Homes Built Faster Act, which received royal assent on November 28, 2022, requires municipalities to permit up to three units per lot as of right where municipal services are available. Edmonton’s Zoning Bylaw 20001, in effect since January 1, 2024, allows up to eight dwellings on an interior lot in its main small-scale residential zone. British B.Columbia’s C.’s Bill 44 requires at least three or four units per lot in municipalities over 5,000 residents, and six near frequent transit. Behind much of this sits the federal Housing Accelerator Fund: $4.4 billion across 241 agreements covering more than 72 per cent of Canadians, with many participating cities committing to allow four units as of right. On the building side, a B.C. Building Code revision on August 27, 2024 began permitting single-exit-stair residential buildings up to six storeys, with sprinklers throughout and no more than 24 people per floor, and Vancouver followed on January 20, 2026. The National Building Code still limits new single-exit multi-unit residential buildings to two storeys, so in most of the country a six-storey building on a narrow lot still needs two stair cores.
With zoning settled, the binding constraints move to the site: soil and groundwater conditions under a lot nobody has investigated in decades, foundations of the buildings next door, stormwater and sanitary capacity in older streets, and frontage works a municipality can require as a condition of building. On a single-family lot those were rarely questions. On a fourplex or a six-storey building they decide the foundation type, the shoring, whether parking can go below grade, and often whether the pro forma survives
The sensible response is to read the ground before committing to the building, rather than after, and to read the approval path at the same time. A desktop review of geology, past uses and adjacent foundations, a small number of targeted test holes and a pre-application meeting with the municipality cost little against the price of a site. Together they tell an owner which form the parcel will carry economically, and how it will be approved: a fourplex on shallow footings that fits the as-of-right envelope, townhomes on a constrained lot, or a six-storey building, with or without a parkade, that will need a development permit.
The strongest objection is that ground conditions are not what is stopping infill. Construction costs, interest rates and rents are, and an owner deciding whether to build at all will reasonably put investigation behind the financing question. That is true, and it is the argument for investigating early. On a marginal pro forma, the cheapest way to lose the project is a foundation surprise found after the land is bought and the design is drawn. A screen done before purchase or before design commitment turns that risk into a price the owner can negotiate.
Calgary adds a second reason not to wait. Council approved citywide rezoning for row houses and townhouses on May 14, 2024, then voted to repeal it on April 8, 2026. From August 4, 2026, 99 per cent of affected properties returned to their earlier zoning, while applications already in process continued under the old rules. On lots that kept R-CG zoning, maximum lot coverage fell from 60 to 55 per cent and height from 11 m to 10 m. Owners who had read their ground and applied kept the larger envelope. Those still deciding lost it.
This month raises the same question across the country. B.C. elects new councils on October 17 and Ontario’s municipalities vote on October 26, and housing is a central issue in both. The British Columbia Real Estate Association’s 2026 local election platform asks candidates for two things: regional housing roundtables to align zoning, missing middle density and development charges across neighbouring municipalities, and as-of-right zoning and streamlined permitting for prefabricated homes. The association cites prefabrication as cutting project costs by as much as 20 per cent, construction waste by up to 70 to 80 per cent and greenhouse gas emissions by up to 43 per cent. Those are affordability and sustainability gains a new council can deliver through zoning. A factory-built fourplex still sits on site-built foundations, though, and still connects to the street’s water, sewer and storm mains, so the ground and the servicing decide whether those savings survive the site.
Three pieces in this issue follow from that. You Asked looks at infill from the developer’s side: how to get the most units from a lot and the fastest approval, with new councils taking office. From the Practice gives a one-day screen for a constrained urban parcel, including its approval path. The Project Profile looks at a six-storey building that replaced a downtown parking lot in Penticton, B.C.
Zoning now tells owners what a parcel may hold, and the councils elected this month will keep changing it. The ground, the pipes, the neighbours and the approval path tell them what it will hold, and the owners who ask those questions first will get the most affordable, sustainable housing out of the lots everyone else overlooked.
Looking at an infill parcel or an oversized lot? The PRI Team can screen it before you commit.
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“After working on both sides of development, the best projects are those with client collaboration.”
Nola Kilmartin, MUP, RPP, MCIP
Vice President, Property & Buildings
nola.kilmartin@priengineering.com