Is Your Lot Eligible for a Multiplex? A BC Owner's Checklist
Not every single-family lot is a good multiplex candidate. Lot size, topography, boulevard trees, FSR limits, and zoning overlays all affect feasibility.
Bill 44 gave most BC single-family lots the right to build a multiplex. But “eligible” and “feasible” are different things. Before spending money on an architect or consultant, walk through this checklist to see if your lot is a realistic multiplex candidate.
The 6-Point Eligibility Checklist
Lot Size
Most municipalities require a minimum lot size of 280–330 m² (3,000–3,500 sq ft) for 4 units. Smaller lots may only support 3 units. For 6 units, most municipalities require proximity to a frequent transit corridor AND a lot size of 450+ m².
Current Zoning
Most RS-1, RS-5, and RS-6 zones in Burnaby and Surrey are eligible. Some heritage zones, ALR land, and floodplain areas are exempt. Check your municipality's zoning map — most have an interactive online tool.
FSR and Height
Floor space ratio (FSR) determines how much total floor area you can build relative to lot size. A 0.6 FSR on a 6,000 sq ft lot = 3,600 sq ft of buildable area — split across 4 units, that's 900 sq ft each. Height limits of 9.5–11 m are standard for SSMUH.
Topography and Site Conditions
Steep slopes significantly increase construction costs. A slope of more than 15% typically requires engineered retaining walls. Rocky soil conditions (common on the North Shore) can double foundation costs.
Boulevard Trees and Protected Features
Boulevard trees along the street frontage are protected under most BC municipal bylaws. A mature boulevard tree can affect your setbacks and driveway placement. Similarly, protected slopes and riparian areas within 30 m of a watercourse can restrict building envelope.
Services and Infrastructure
Multiplexes typically require upgraded water and sewer service connections. In older neighbourhoods, the lateral from the main to your property may be undersized for 4–6 units. Service upgrades can cost $15,000–$50,000+ depending on condition and distance.
Quick Pre-Screen: The 5-Minute Test
Before doing anything else, answer these three questions:
- Is your lot at least 280 m² (3,000 sq ft)?
- Is your zoning RS, R1, or equivalent residential single-family?
- Is the lot reasonably flat (less than 15% slope)?
If you answered yes to all three, your lot has basic multiplex potential. The next step is running the numbers — use the Fort Feasibility Calculator to get a rough pro forma in under two minutes.
When to Call a Professional
If the quick screen looks promising, the first professional you need is an architect or building designer, not a lawyer or real estate agent. A $3,000–$5,000 massing study will tell you exactly what can be built on your site within the zoning envelope. That's the document you need before making any commitments.
Fort offers free 20-minute lot assessments for BC property owners considering a multiplex. Bring your address and we'll tell you what we see in the numbers before you spend anything on consultants.
Have Questions About This Topic?
Ask Dennis AI for deeper answers on zoning, feasibility, or the development process — or run your lot through the calculator.
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