Decks
Check size / scopeWaterloo requires a building permit for a deck more than 24 in (2 ft) above ground or with a roof/cover, and states that an uncovered deck under 24 in does not require one. The exact 24-in boundary remains conditional.
Waterloo, ON
Building permits in Waterloo
Waterloo says a permit is typically required for interior work such as finishing an unfinished basement, adding or removing walls, structural changes, plumbing changes or changes in how a space is heated or used.
Official sources checked Sep. 24, 2026
Permit rules by project
Pick the project that matches your work. These are starting rules for Waterloo; property-specific zoning, heritage and trade approvals can still apply.
Sheds & accessory buildings
Check size / scopeWaterloo states that a detached one-storey storage shed up to 15 m² with no plumbing does not need a building permit; larger or non-qualifying structures do.
Basement renovations
Permit requiredWaterloo explicitly lists basement renovation/finishing work—such as walls, insulation, structural changes, plumbing or creating a second unit—as building-permit work.
Secondary suites & ADUs
Permit requiredWaterloo explicitly lists new secondary units among projects requiring a building permit.
Home additions
Permit requiredWaterloo states that new additions require a building permit and separately says any addition that changes the home footprint needs a permit.
Interior alterations
Depends on scopeWaterloo requires permits for regulated alterations and basement/interior work, while like-for-like plumbing fixture replacement and other minor maintenance can be exempt.
Walls / structural work
Permit requiredWaterloo explicitly includes structural changes within basement/renovation work that requires a building permit.
Pools / hot tubs
Depends on scopeWaterloo says pool and hot-tub enclosures do not require a building permit but are controlled by other municipal bylaws/permit processes.
Garages / carports
Depends on scopeWaterloo requires a building permit for detached garages over 10 m² or with plumbing, while smaller unplumbed structures can be exempt.
Plumbing / HVAC
Depends on scopeWaterloo’s guidance requires permits when plumbing is added or changed in regulated work, while replacing the same fixture in the same location is listed as no-permit. HVAC/electrical can follow separate rules.
Fences
Depends on scopeWaterloo states that ordinary fences do not need a building permit, while pool/hot-tub enclosures follow other municipal bylaw/permit processes.
Retaining walls
Confirm with cityWaterloo’s current permit and engineering information does not give one citywide height-only retaining-wall rule for every residential property. Confirm height, location, drainage and engineering requirements with the City.
Demolition
Permit requiredWaterloo states that a building permit is required to demolish a building or part of a building, and its general guide includes interior demolition.
Apply or ask Waterloo
Use the municipality’s permit office for current forms, fees, drawings and questions about your property.
Waterloo Building Department
- Phone
- 519-747-8712
- building@waterloo.ca
- Hours
- In-person permit counter Mon–Fri, 8:30 a.m.–4:30 p.m.
- Address
- 100 Regina Street South, Waterloo, ON N2J 4A8
Your application route
Open the official permit page ↗Use the official permit page to confirm project requirements, forms, fees and the current application process.
Good to know in Waterloo
- The city publishes project-specific checklists and accepts building-permit applications through its online building portal.
- Ontario municipalities issue building permits within the provincial code framework, while zoning and other local approvals still apply to the property. Trade, conservation, heritage or utility approvals may be separate.
Official sources
Use these official links to confirm the current rule for your Waterloo property.
View 2 official sources
Sources checked Sep. 24, 2026. Requirements can change; the municipality makes the final permit decision.
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