Buying a Home With an Unpermitted Renovation in Ontario: What Buyers Should Know Before Closing

Buying a home with recent renovations can be appealing. A finished basement, new bathroom, expanded kitchen, backyard addition, or converted garage may make a property more attractive and functional. However, if that work was completed without the permits required by the municipality, the buyer may be taking on more than they realize.

Unpermitted renovations can create legal, financial, insurance, safety, and resale concerns. In some situations, the work may need to be inspected, altered, or even removed before it can be brought into compliance.

Ontario’s Building Code Act generally requires a building permit before certain construction or demolition work takes place, and municipalities are responsible for enforcing building permit requirements in their communities. Building permits help ensure that construction complies with the Ontario Building Code, zoning rules, and other applicable laws.

At Mayfair Law Group, we help Ontario homebuyers identify potential legal issues before closing. If a home includes renovations that may not have been properly permitted, understanding the risks before becoming firmly committed can help prevent costly surprises later.

What Is an Unpermitted Renovation?

An unpermitted renovation is construction or alteration that required municipal approval but was completed without the required building permit.

Not every cosmetic improvement requires a permit. Painting, replacing flooring, or installing new cabinets may often be completed without one. More significant work, however, may require municipal approval.

Ontario explains that building permits may be required when constructing, renovating, demolishing, or changing the use of a building. Municipal building departments generally administer and enforce those requirements.

Common examples of potentially permit-required work include structural alterations, additions, basement renovations, plumbing changes, certain electrical work, new bathrooms, decks, secondary suites, and changes that affect how part of a building is used.

Whether a particular renovation required a permit depends on the nature of the work and local requirements.

Why Building Permits Matter

A building permit is more than administrative paperwork.

The permit process allows the municipality to review proposed work before construction begins and, where required, inspect the work as it progresses. This helps determine whether the renovation complies with building safety standards, zoning requirements, fire protection rules, structural requirements, and other applicable laws.

Ontario’s Building Code Act states that construction requiring a permit should not proceed unless the chief building official has issued one. The legislation also identifies the role of building owners in maintaining buildings in accordance with the Act and Building Code.

When renovations are completed without this process, a buyer may have no confirmation that the work was reviewed or inspected by the municipality.

How Can Buyers Discover Unpermitted Work?

Unpermitted renovations are not always obvious.

A beautifully finished basement may look completely professional while still lacking required approvals. An addition may have existed for many years without appearing in municipal records. A seller may even have purchased the property after the work was completed and be unaware that permits were never obtained.

Buyers should pay attention when listing information refers to recently completed additions, basement apartments, structural changes, new bathrooms, converted garages, or major renovations.

Depending on the circumstances, buyers or their representatives may be able to review municipal permit records or ask the seller for copies of permits, drawings, inspection reports, or final approvals.

A home inspection can also help identify renovations that warrant further investigation. However, a home inspector does not necessarily determine whether municipal permits were issued, so permit research may need to be completed separately.

What Happens If the Municipality Discovers the Renovation?

A common concern is whether buying the home makes the new owner responsible for correcting work completed by a previous owner.

The answer depends on the circumstances, but municipal compliance issues can follow the property. A municipality that discovers unpermitted work may require the current owner to address the issue.

That could involve applying for a permit after the fact, providing drawings, opening walls or ceilings so work can be inspected, obtaining professional reports, completing additional construction, or bringing the renovation up to applicable standards.

In more serious situations, work that cannot be approved may need to be altered or removed.

This can turn what appeared to be a valuable renovation into a significant unexpected expense.

Unpermitted Basement Apartments Can Create Added Risk

Basement apartments and secondary units deserve particular attention.

A finished basement may be advertised as having an additional bedroom, kitchen, or rental suite, but the existence of those features does not necessarily mean the space has been legally approved for that use.

A buyer should consider whether required permits were obtained and whether zoning, fire safety, egress, ceiling height, electrical, plumbing, and other requirements were satisfied.

Ontario law also provides that certain changes in the use of a building can require a permit even if no new construction is proposed when the change increases the level of hazard under the Building Code.

This is particularly important for buyers who are relying on rental income when determining whether they can afford the property.

Could Unpermitted Work Affect Mortgage Financing?

Potentially.

Mortgage lenders assess both the borrower and the property being used as security for the loan. If a significant portion of the property appears to be unauthorized, unsafe, or inconsistent with its approved use, questions may arise during appraisal or underwriting.

This can become especially important if the buyer is relying on the value of a renovated basement apartment, addition, or other improvement when obtaining financing.

A buyer should not assume that because the home has already been renovated, the lender will automatically recognize the renovation's full value.

If permit concerns arise close to closing, there may be limited time to investigate or resolve them. This is one reason buyers should raise questions about significant renovations before waiving financing, inspection, or other important conditions.

Insurance Can Also Be a Concern

Home insurance is another area where unpermitted work may create uncertainty.

Insurers assess the construction, use, condition, and risks associated with a property when determining coverage. If a major renovation was completed without required approvals, the insurer may ask additional questions or require information about the work.

Problems can become more serious if an insurance claim later involves the renovated area.

For example, an electrical, plumbing, structural, or fire-related loss connected to unauthorized work could lead to questions about how the renovation was completed and whether appropriate standards were followed.

Buyers should therefore make sure their insurer has accurate information about the property before closing rather than discovering a coverage issue after a loss occurs.

What About Future Resale?

Unpermitted renovations can also become a problem when the buyer eventually becomes the seller.

Future purchasers may ask the same questions about permits, legality, and compliance. A home inspector or buyer's lawyer may identify the issue, potentially affecting negotiations or delaying the transaction.

A renovation that appeared to increase the property's value may instead create uncertainty about what the next buyer is willing to pay.

Addressing permit concerns before completing the original purchase can therefore protect not only the current transaction but also the property's future marketability.

Can the Seller Be Required to Fix the Problem?

Whether a seller must resolve unpermitted renovations depends largely on the Agreement of Purchase and Sale and the facts surrounding the transaction.

If the buyer's offer contains appropriate conditions, the buyer may have an opportunity to investigate permits and decide how to proceed before becoming firmly committed.

The parties may also negotiate a solution. The seller might agree to obtain permits, provide documentation, correct deficiencies, adjust the purchase price, or address the matter in another way before closing.

Once an agreement becomes firm, however, the buyer's options may be more limited. Buyers should not assume that discovering unpermitted work automatically gives them the right to terminate the deal.

The wording of the contract matters, which is why legal advice should be obtained as soon as the issue is discovered.

Why the Agreement of Purchase and Sale Matters

The Agreement of Purchase and Sale determines the legal obligations of the buyer and seller.

Conditions involving financing, inspection, lawyer review, or other due diligence may provide opportunities to investigate concerns before the transaction becomes unconditional.

Buyers may also want representations or warranties regarding renovations, permits, zoning, or the lawful use of parts of the property where those issues are particularly important.

The appropriate wording depends on the transaction. A buyer purchasing a home specifically because of a basement apartment, for example, may have different concerns from someone who simply plans to use the basement personally.

A real estate lawyer can review the agreement and identify whether additional protections should be considered.

Do Not Assume the Renovation Is Legal Because It Looks Professional

One of the biggest mistakes buyers can make is assuming that attractive workmanship means a renovation was properly approved.

Permits are designed to help municipalities verify compliance with building standards and local laws. Ontario specifically notes that permits allow municipalities to ensure planned work meets Building Code standards and applicable by-laws.

The quality of the finishes alone does not establish whether the structural, plumbing, fire safety, zoning, or other requirements were satisfied.

When a significant renovation adds meaningful value to the property, buyers should consider verifying its status before relying on it.

Speak With Mayfair Law Group Before Closing on a Renovated Home

An unpermitted renovation does not necessarily mean that you should walk away from a home, but it is a risk that should be understood before closing. Permit issues can affect safety, municipal compliance, financing, insurance, future resale, and the true value of the property you are purchasing.

At Mayfair Law Group, we help Ontario buyers review Agreements of Purchase and Sale, investigate real estate concerns, and navigate problems that arise before closing. If you discover that a home has a basement, addition, structural alteration, or other renovation that may not have been properly permitted, our team can review the situation and help you understand your options before you take ownership.

Contact Mayfair Law Group today to speak with an Ontario real estate lawyer before closing on a home with potentially unpermitted renovations.

FAQ

How do I know whether a renovation required a building permit in Ontario?

Permit requirements depend on the type of work performed. Significant construction, structural alterations, additions, certain renovations, demolition, and some changes of use generally require permits. Buyers can contact the municipality responsible for the property to investigate specific work.

Can I buy a house that has unpermitted renovations?

Yes, but buyers should understand the potential risks first. Purchasing the property may leave the new owner dealing with municipal approvals, inspections, corrective work, insurance concerns, or future resale issues.

Can a municipality make me fix work completed by a previous owner?

Depending on the circumstances, the current property owner may need to address outstanding compliance problems even when the renovation was completed before they purchased the home. The municipality may require permits, inspections, corrective work, or other steps.

Does a finished basement automatically mean it is a legal basement apartment?

No. A finished basement and a legally approved secondary unit are not the same thing. Zoning, permits, fire safety, Building Code requirements, and other rules may need to be satisfied before the space can legally be used as a separate dwelling.

Should I contact a real estate lawyer before buying a home with unpermitted work?

Yes. A lawyer can review the Agreement of Purchase and Sale, determine what contractual protections may apply, help assess the legal risks, and advise on possible solutions before you waive conditions or complete the purchase.