Can a Neighbour Build Right on the Property Line in Ontario?

A neighbour starts building a garage, addition or fence very close to the lot line, or seems to be building over it. You may wonder whether that is allowed and what you can do.

Setback distances come from your municipality's zoning by-law and from building permit conditions, and they differ from place to place. This article covers the rules that apply to the line itself and the options if your neighbour crosses it.

Who decides how close a neighbour can build

How close a building may sit to a lot line depends on the local zoning by-law, the building permit issued for the project, and any approvals the neighbour obtained. Those numbers vary by municipality and by zone, so there is no single Ontario distance. A short call or visit to your municipality's building or planning department can tell you what was applied for and approved.

Zoning and permits deal with how a building may be used and placed, while the question of who owns the land is a separate one. If you think a building may cross the line, a survey can show where the boundary lies, and a lawyer can confirm how the rules apply to your situation.

Things that sit on the line: trees and fences

• A tree whose trunk grows on the boundary between adjoining lands is the common property of both owners.
• Injuring or destroying a boundary tree without the consent of the owners is an offence under the Forestry Act.
• An owner may plant trees on the boundary only with the consent of the adjoining owner.
• A municipal tree by-law may also require a permit to injure or destroy trees.

For fences, an owner who wants a boundary fence built or repaired may give the municipal clerk notice, in the prescribed form, asking fence-viewers to arbitrate. The award may be appealed to the referee within fifteen days of receiving it. Where a municipal fence by-law covers the land, the Line Fences Act generally does not apply, apart from s. 20.

When a building actually crosses the line

Encroachments raise questions of ownership. In general, an action to recover land must be brought within ten years, and when that period ends the title of the person who failed to act is extinguished. Land registered under the Land Titles Act is treated differently: no title adverse to the registered owner can be acquired by any length of possession, with a narrow exception for a first owner registered with only a possessory title.

A right of way or other easement based on use cannot be defeated once enjoyed for twenty years, and becomes absolute after forty years, unless it was enjoyed under express consent given by deed or in writing. Whether your parcel is under Land Titles, and when it was converted, affects which rules apply, so check your parcel register.

If the dispute is only about where the boundary lies, there is no limitation period for a proceeding seeking only a declaration with no consequential relief. A survey is usually the starting point.

Court options and time limits

• A judge of the Superior Court of Justice may grant an interlocutory injunction or mandatory order where it appears just or convenient.
• A court that can grant an injunction may award damages in addition to, or instead of, the injunction.
• The Small Claims Court hears money claims up to $50,000, exclusive of interest and costs.

The basic limitation period is two years from the day the claim was discovered. Discovery is the earlier of the day you actually knew the relevant matters and the day a reasonable person in your situation ought to have known them. No proceeding may be started after the 15th anniversary of the act or omission, whatever the date of discovery.

If construction damages your property, the claim usually rests on general principles such as negligence or nuisance, which asks whether the interference with your land is unreasonable in all the circumstances. Fill, grade changes and drainage can matter too. A municipality may regulate fill, topsoil removal and grade changes by by-law and require permits. Collected surface water must not be diverted onto land that would not naturally receive it, or liability for damages can follow. A right to drain collected water onto a neighbour's land may arise from 20 years of continuous, open, peaceful, uncontested use without permission, but a court must confirm it and it can be lost if the drainage is increased.

What to do next

• Take dated photos and videos of the work and any damage.
• Ask the municipality which permits and approvals were issued, and whether a stop-work or compliance concern can be raised.
• Order or review a survey if you are unsure where the line is.
• Write to your neighbour calmly, describing the problem and what you want done.
• Note the date you first learned of the problem, because limitation periods run from discovery.
• Speak with a lawyer before work goes further, since injunction timing matters.

Frequently asked questions