Building or legalizing a secondary suite in Victoria BC usually costs far less than any other way to add a rental unit, because the structure, roof and services are already there. Victoria builder Fayzebuilt publishes $40,000 to $70,000 for a typical basement suite renovation, or about $110 to $160 per sq ft (page checked Oct 2026). What decides your real secondary suite cost is how much of the BC Building Code's suite requirements your house already meets: fire separation, smoke and CO alarms, exits, ceiling height and heating. This guide walks through each requirement and the permit path for both a new suite and an existing one you want to make legal.
What does a secondary suite cost in Victoria?
| Budget line | Published share or range (Fayzebuilt, 2026) | What pushes it up |
|---|---|---|
| Whole basement suite renovation | $40,000 to $70,000 ($110 to $160 per sq ft) | Low ceilings, no outside door, wet basement |
| Kitchen | 10% to 15% of budget | Moving plumbing, a new range circuit |
| Bathroom | 10% to 20% of budget | Below-grade drains that need a pump |
| Utilities and systems | About 15% of budget | Panel capacity, separate heat and ventilation |
| Permits and applications | About $1,400 to $7,000 | Municipality and declared value |
Those figures assume a reasonably dry basement with workable headroom. Lowering a floor, adding an exterior stair or waterproofing a foundation can each cost more than the finishes. A builder should see the space before giving you a number.
What are the requirements for a legal secondary suite in BC?
The BC Building Code governs how a suite is built; your municipality's zoning governs whether you can have one. The code's secondary suite rules were rewritten in Revision 2 of the 2018 code (Information Bulletin B19-05, December 2019). The main points:
Fire separation between the two units
The suite and the main home must be separated by a fire separation that acts as a continuous barrier to smoke and fire. The required rating depends on how the smoke alarms are connected:
| Smoke alarm setup | Fire-resistance rating required |
|---|---|
| Smoke alarms not interconnected | 45 minutes |
| Additional photo-electric alarms in each unit, interconnected | 30 minutes |
| Every smoke alarm in the house (both units and common spaces) interconnected | 15 minutes |
| House fully sprinklered | Rating not required |
The bulletin notes that both the 15-minute and 30-minute construction specifications allow 12.7 mm regular gypsum board and also meet the sound rules. Doors in the separation can be 45 mm solid wood with a self-closer instead of a labelled fire door.
Smoke and CO alarms
Interconnected smoke alarms must be photo-electric. All carbon monoxide alarms in a house with a secondary suite must be interconnected. Wireless interconnection is allowed for both, which can save opening up finished ceilings in an older home.
Exits and egress
Each unit needs a safe way out. A second, separate means of egress may be required depending on the design. Where a window serves as that second means of egress, it must open at least 1 m high by 0.55 m wide, with the sill no more than 1 m above the floor. A shared exit route must be separated from both units by a fire separation.
Ceiling height, sound and size
- Ceiling and clear heights in a suite are the same as for any other dwelling unit.
- Sound separation between the units is STC 43 or ASTC 40.
- The old code limit of 90 m2 or 40% of the house was removed from the code definition in 2019. Your municipality may still cap suite size in its zoning bylaw, so check locally.
- A house with a secondary suite cannot sit above or below another unit, so suites are not allowed in up/down duplexes.
Separate heat and ventilation
Each unit must have its own temperature controls. The code allows alternatives to a fully separate heating or ventilation system, but a shared forced-air furnace that moves air between the two units is the classic problem in older Victoria houses, because it can carry smoke from one unit to the other. Many owners solve it by giving the suite a separate heat source, such as electric baseboards or a small ductless heat pump, and closing off the shared ducts. Your designer and the building official will tell you which path your house needs.
Suite electrical requirements, including the interconnected alarm wiring, the suite's own circuits and whether the panel can carry the extra load, are permit work for a licensed electrical contractor. ACAP LTD's in-house electrical division handles that scope on our suite projects.
How do I legalize an existing secondary suite in Victoria?
Many Greater Victoria houses already have a basement suite that was never permitted. Making it legal follows the same building permit path as a new suite, with one useful difference: the code recognizes that existing construction can make full compliance impractical.
- Confirm zoning. Check that your municipality allows a secondary suite on your lot and whether it limits suite size or parking. In Langford, a secondary suite must be completely contained within the principal dwelling, and Bylaw 2183 removed the minimum lot size and maximum floor area for suites.
- Get the suite assessed. A designer or contractor documents what is there: ceiling heights, the separation between units, alarms, exits, heating and ductwork.
- Use the alternative compliance methods. For alterations to existing buildings, Table 1.1.1.1.(6) in Division A of the BC Building Code lists alternative compliance methods you may use where existing construction is a practical barrier to the standard solution.
- Apply for a building permit with drawings, plus plumbing and electrical permits for that work. In the City of Victoria, a fee holiday waives City permit fees from January 29, 2026 to January 29, 2027, which makes now a good time to legalize.
- Do the work and pass inspections. Opening walls for the fire separation, wiring interconnected alarms and separating the heat are the usual items.
The bulletin is clear that the code is not meant to be applied retroactively to suites nobody is changing; legalizing is about the work you permit now. Confirm the current requirements with your municipality's building department, because the BC Building Code has been revised since that 2019 bulletin.
Secondary suite vs garden suite: which should I build?
A secondary suite is the low-cost option. A detached garden suite costs several times more, but gives each household its own building and often earns more rent. In the City of Victoria, Schedule M does not permit a garden suite where the house already has a secondary suite, although lots that qualify for small-scale multi-unit housing follow different rules. Compare the full costs in our garden suite cost guide, or see all three options side by side in duplex vs garden suite vs house with suite.
A suite also cannot be sold separately: under the code definition, both units in a house with a secondary suite form a single real estate entity. If you want units you can sell, look at a duplex or multiplex instead.
Who should build or legalize my suite?
Suite work touches framing, drywall, plumbing, electrical and mechanical all at once, and the inspector looks at how they fit together. A general contractor who coordinates all of it under one permit keeps the job from stalling between trades. See how ACAP LTD manages permits and inspections on our general contracting page, or book a site visit and quote for your suite.