Can You Build a Duplex or Fourplex on Your Lot in British Columbia?

If you own a house in a British Columbia city, you may have heard that new provincial rules let owners build a duplex or fourplex. The reality is more specific: the rules change what local zoning must permit, and they depend on your lot.

This article walks through the lot-size and servicing conditions, the exemptions, and the approvals that still apply. The point is to help you ask the right questions before spending money on plans.

This article covers the law of British Columbia.

What the provincial zoning changes actually did

The province's small-scale multi-unit housing changes work through local zoning. Under the Local Government Act, a zoning bylaw must permit the housing uses and densities set out in section 481.3 by June 30, 2026, unless an exemption applies. In plain terms, the change is about what zoning must permit on your lot, and how that fits your own plans depends on your situation, so it is worth confirming with a lawyer.

The rules were amended again by Bill 25 in 2025. Local governments had to update bylaws by June 30, 2026 unless they applied for an extension. That date has passed, though some municipalities are still adopting bylaws, so confirm what your city's zoning says today.

Does your lot meet the size and location conditions?

For parcels zoned only for single-family or duplex use inside an urban containment boundary, or in a municipality over 5,000 people, a parcel of 280 m² or smaller must allow at least 3 units. A parcel larger than 280 m² must allow at least 4 units.

Six units is a narrower case. Single-family and duplex lots larger than 280 m² in a municipality or regional district with a population of at least 5,000 must allow up to 6 units if the lot is near a frequent transit bus stop. That means a bus at least every 15 minutes on average, 7 a.m. to 7 p.m. Monday to Friday and 10 a.m. to 6 p.m. on Saturday and Sunday.

If you do not meet these conditions, you may still have rights to smaller additions. Zoning in a restricted zone must permit at least one additional unit within the house and/or in another building on the same parcel. The unit figures above come from the Province's summary, and the prescribed numbers are set in regulation.

Servicing, large lot and heritage exemptions

Several exemptions can remove a lot from the minimum unit rules:

• Servicing: land not connected to a water or sewer system provided as a service by a municipality or regional district is exempt from the minimum unit counts in sections 481.3(4) and (5).
• Large lots: parcels larger than 4,050 m², and land in a zone whose minimum subdivision lot size is 4,050 m², are exempt from those counts.
• Heritage: land protected under section 12.1(2) of the Heritage Conservation Act, or designated as protected under a heritage bylaw on the date the section came into force, is exempt from those counts.

A local government relying on one of these three exemptions (servicing, large lot or heritage) must give the minister written notice identifying the land and the exemption. Separately, the 3 to 4 unit rule does not apply where the zone already allows three or more dwelling units on the parcel. The rules also apply only where residential use is permitted on the parcel. If your lot is in the Agricultural Land Reserve, separate housing rules apply and extra approvals may be needed.

What still applies after zoning permits the units

Zoning permission does not replace the other approvals. Before any stage of a building project begins, required permits must be obtained, and the local government or First Nation issues building permits. If your land is in a designated development permit area, construction cannot start until a development permit is issued, unless an exemption applies.

Municipalities cannot use development permit or land use powers to unreasonably restrict the required use or density. They also cannot use conditional density rules like amenity bonuses to achieve the minimum units. Details such as height, setbacks and parking vary, so check your bylaw.

Development cost charges may apply to new units. They are paid at subdivision approval or when the building permit is issued. Exemptions include developments with fewer than four self-contained dwelling units (unless the bylaw says otherwise), units no larger than 29 m², and building permits for work costing $50,000 or less.

Building more units on one lot is also different from subdividing it. A subdivision goes through an approving officer, who may refuse a plan that does not conform to the Local Government Act or applicable zoning and subdivision bylaws.

What to do next

• Measure your lot area and compare it with 280 m².
• Confirm whether you are inside an urban containment boundary or in a municipality over 5,000 people.
• Check for a frequent transit bus stop nearby if you hope for six units.
• Ask whether your lot is connected to municipal water and sewer.
• Check for heritage protection and development permit areas.
• Speak with a lawyer before relying on a possible exemption or after a refusal.

Frequently asked questions