Your home’s permit history and renovations

Written by the Square One team

Updated July 10, 2024 | Published November 18, 2018

If you’ve finally found a beautiful century home, but it needs modernization, or you fantasize about having an open plan kitchen/living area in your current home, renovations are undoubtedly on your agenda.

Before you have plans drawn up, hire a contractor and dive into the project, you may want to do a bit of homework. Make the time to research the home’s building permit history. Knowing about the modifications that have already been made will help you to avoid surprises and unexpected costs as you move forward with your renovations.

A couple planning their home's renovation

The important points

  • Building permits form an official record of major changes to a property, signifying that the renovations were inspected and certified.
  • Knowing your home’s permit history will help you avoid nasty surprises when you do further work.
  • The local municipal building office will keep records of previous building permits and issue new permits.

Home improvement permits – study your history

Building permits are the official record of changes made to a property and indicate that the changes were inspected and certified as safe and sound. It’s common to arrange for a home inspection when buying a new property to uncover any current problems, but few people think about inspecting the changes that have been made in the past. Yet Canadians spent $68 million on renovations in 2014, according to the Altus Group. Why not protect your investment?

Excavator at rest in the backyard

Home inspections can turn up quite a few types of flaws, but they don’t reveal problems with underground aspects of a structure since they’re not visible. Is your foundation solid? Is the weeping tile connected? Were there any changes to the foundation made previously? A review of the property’s building permits will give you this important information.

When do I need a building permit – protect yourself

It isn’t the responsibility of your realtor or your lawyer to alert you to these issues; you need to do the work yourself. By calling your municipal building department and checking the permit history of your home or prospective home, you can ensure that you are protected in the event that problems arise.

For example, if you experience an electrical fire and it is traced to wiring that has been redone without permission from the municipality, your insurer won’t be happy.

“Building permits can work for you when you have them, and can work against you if you don’t,” wrote contractor Mike Holmes in the National Post. “They can also help you to make better-informed decisions at the time of buying a home with major alterations.”

Just having building permits on file for previous renovations isn’t good enough. The permits need to be closed, meaning that the renovations have been inspected and approved by the municipality. Before embarking on renovations or purchasing a home that has had work done, ensure that these approvals have been given. The current homeowner, whether that’s you or someone else, is liable for permits that have not yet been closed.

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My building permit – common changes

Man tries to install a new sink faucet

Let’s take a look at some of the upgrades that you might want to make if you buy and renovate an old home—with the permission of your municipal building department, of course:


If your home was built before 1960, it probably has galvanized pipes which are susceptible to clogging and corrosion. If plumbing is involved in your reno, you’ll want to consider replacing your galvanized hardware with copper or PVC pipes.


Old knob and tube wiring is a fire hazard that should be replaced. If you bring your wiring up to code, it will also be able to handle the electrical load of today’s appliances and devices. It’s no fun to regularly blow a fuse simply by plugging your hairdryer into an outlet when the dishwasher is running.

Hazardous materials

Old pipes, floors, and walls may contain asbestos, which can be extremely harmful when the dust is inhaled. The paint in old homes is often lead-based, and lead is poisonous if ingested. Replacing these materials with new ones will add additional peace of mind. Take extreme care if you decide to remove asbestos or lead-based paint yourself; it’s usually best to hire professionals in these cases.

Outdated layouts

Your home may have a marvelous exterior, but a layout that doesn’t suit today’s family lifestyle. Do you want to knock down some walls or add closets or bathrooms? You’ll need to explore the possibilities with an expert first since you’ll want to maintain the structural integrity of the building.

Before you begin a renovation or purchase a home, one of your first stops should be the municipal building office. Not only can the staff there take you through the building’s renovation history; they can explain exactly which permits and approvals will be needed as you turn your dwelling into a dream home.

Want to learn more? Visit our Home Improvement resource centre for tips and inspiration for your next big home improvement project. Or, get an online quote in under 5 minutes and find out how affordable personalized home insurance can be.


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