Source-reviewed city index
Common residential permit questions for London, organized by project. Open any row to see the conditions, official evidence and property-specific limitations behind the answer.
Latest represented review
Oct 1, 2026
A permit answer can still depend on dimensions, use, plumbing, structural work, zoning or the exact property. BuildRules keeps those conditions visible instead of reducing the rule to a false green-or-red score.
Do you need a permit for an ARU or basement apartment in London, Ontario?
A building permit is required for every new ARU, whether it is an interior/basement conversion, converted garage, addition or detached unit.
1 official source
Do you need a permit to renovate a basement in London, Ontario?
London requires permits for basement finishing that creates rooms or living space, basement apartments, excavation to increase headroom and below-grade entrances.
1 official source
Do you need a permit for a deck in London, Ontario?
A side or rear deck under 600 mm can be permit-exempt only when it is not attached to the house; an attached low deck still requires a permit.
2 official sources
Do you need a permit for a home addition in London, Ontario?
Yes. London lists additions to existing buildings among projects that require a building permit.
1 official source
Do you need a permit for a shed in London, Ontario?
A shed can be permit-exempt when it is under 15 m², one storey, free-standing, storage-only and has no plumbing.
1 official source