Air Quality Testing in Toronto

Full breakdowns: air quality testing cost and asbestos testing cost.

We test Toronto homes and workplaces for mold and asbestos, the two things behind most indoor air quality worries. Our own inspectors come to you, an accredited lab analyzes every sample, and a mould air test is CAD 550 plus tax, with the outdoor baseline and written report included. You'll get a flat-rate quote before anyone books a visit.

You're probably here with a smell, a stain or a renovation you don't want to start blind. We've run more than 15,000 inspections since 2005, and the plan never changes: look first, sample only what needs sampling, let the lab give the answer. If you're wondering what indoor air quality covers before you call, that guide is a good start.

Last updated: 2 November 2026

Most Toronto homes went up when asbestos was still common in building materials. The 2021 census counts about 1.16 million occupied dwellings in the city. Of those, 58.1% were built before 1981 and 67.5% before 1991, and Health Canada says that before 1990 asbestos was mainly used for insulating and fireproofing buildings and homes. Picture three homes on a Toronto street: two of them were built in that window.

Those city averages hide huge swings from one neighbourhood to the next. In Runnymede-Bloor West Village, 84% of homes date from 1960 or earlier. In Fort York-Liberty Village, 3% are older than 1981. The two neighbourhoods need different conversations, even though both have a Toronto postal code.

Source: City of Toronto neighbourhood profiles, 2021 census. Percentages are rounded, and the city totals are our own sum of the 158 neighbourhoods.

Take any of those numbers with some caution, though. A neighbourhood average can't tell you about your house. A 1920s semi may have a 2015 basement, and a 2005 addition can sit on top of 1950s pipe wrap. We go by what's in the wall and what's about to be disturbed, not by the date on the listing. Here's what each era usually means for a test:

Mold needs moisture, so a dry 1920s semi can be fine and a three-year-old condo can have a problem. Health Canada's advice starts there: control humidity and repair water damage. That's why a Toronto inspection starts with where water has been.

Toronto has given plenty of homes a reason to ask. On July 16, 2024, Toronto Pearson recorded 97.8 mm of rain, its fifth rainiest day on record, including 26 mm in a single 10-minute span. The City's 311 line took more than 700 calls about basement flooding that day. A basement that dried out and got new paint can still have damp insulation behind the wall.

Towers have their own version of the problem. Nearly half of Toronto's homes (46.7%) are in buildings of five storeys or more, where the moisture usually comes from a window that runs wet all winter, a leak from the unit above or a bathroom fan that doesn't move much air. The stain on the sill is easy to see, but the drywall behind it can hold more.

Health Canada says that in most situations it does not recommend testing the air for mould. An air test can't predict health effects, and it often says little about what caused the damage. Canada has no health-based exposure limit for indoor mould either, so no lab report can say your air is "safe" in that sense.

We agree with most of that, and it's why we walk the home first. If you can see the growth and you know where the water came from, you may not need an air sample at all. A visual inspection is CAD 95 plus tax for that reason.

Health Canada also names the case where air testing helps: concerns that stay unexplained after an inspection, especially after flooding, roof leaks or pipe leaks that may have reached wall cavities. A spore test can then point to a hidden problem. A Toronto basement that took on water in July 2024 can fit that description, and that's when our mold testing earns its price, because we compare the indoor sample with an outdoor baseline, so the count has something to be measured against.

Once sampling makes sense, an accredited third-party lab reads the samples, so the person who took them isn't the one grading them. It's the same lab we use everywhere else, and the Toronto price is the same as well.

Mold testing

Air samples in the rooms that worry you, one sample outside as a baseline, and surface samples where we can see growth. The lab names the spore types and counts them. Mold testing can also cover the check after a cleanup crew finishes.

Asbestos testing

Small samples of the materials you plan to disturb, such as ceiling texture, floor tile, plaster or pipe wrap, sealed on site and analyzed under a microscope. Asbestos testing gives you a yes or no for each material.

1. 1

   Before the visit

   You tell us what you're seeing

   Call or use the form. You get a flat-rate quote based on how many samples or materials the job is likely to need.

2. 2

   Visit day

   We walk the home before we sample anything

   Moisture readings, the basement, bathrooms, windows and the materials you plan to touch come first, so the samples go where the question is.

3. 3

   Within 1 business day of the visit

   You get the written inspection report

   What we saw, where we sampled and why, in plain language.

4. 4

   2 to 5 business days for mold, 3 to 4 for asbestos

   The accredited lab returns its results

   Surface samples tend to come back faster than air samples. Rush analysis is available for an added fee.

You can read more about what happens during an inspection before you book.

Ontario's asbestos rule puts the legal duty on some owners and not on others. Under Ontario Regulation 278/05, section 10, an owner must have materials likely to be disturbed examined for asbestos before tendering or arranging demolition, alteration or repair. Section 2(4) exempts an owner of a private home that they or their family live in, and an owner of a building of up to four units when one is occupied by the registered owner or their family.

So a landlord with a 12-unit walk-up, a condo corporation or an office owner in Toronto has that duty, and a family renovating its own Bloor West bungalow doesn't. We're inspectors, not lawyers, so check your own case if it's close. But the exemption covers the owner only. The regulation still applies to the employers and workers doing the repair, so a careful contractor may well ask what's in that ceiling before cutting it.

If you've searched the "3-5-7 rule", it comes from Table 1 of the same regulation. It sets the minimum number of bulk samples for each area of one material:

One result of 0.5% or more asbestos by dry weight makes the whole area of that material asbestos-containing under the regulation, and the lab doesn't need to analyze the rest. A positive result is a planning decision. If you're not renovating, you can often leave the material alone. If you are, a qualified abatement contractor handles it, and the written report tells them exactly what they're dealing with.

Toronto is almost evenly split between owners and renters (48.1% of households rent), and 30.4% of homes are condominiums. If you rent or own a condo, the leak may not be yours to fix, so start with the person who can fix it.

We need the owner's OK, or someone authorized by the owner, to inspect a property. Tenants without that approval can still book a virtual inspection for CAD 100 plus tax, which is often enough to know what to raise with the landlord. Property managers and owners of larger buildings should look at our commercial air quality testing.

Toronto prices are the same as everywhere else we work. Each price below is in Canadian dollars, plus tax.

Slow down on the sample count, because that's what moves your total. Two rooms for mold come to $810, and three rooms come to $1,070. A bungalow with a popcorn ceiling, vinyl tile and pipe wrap is three asbestos materials, so $930. Six materials is $1,680. House size matters far less than how many samples or materials the job needs.

You'll see lower prices online, and some Toronto companies do charge less for a first step. Before you compare, ask whether the number includes the lab analysis, an outdoor baseline and a written report. Those three things are what make a result useful to a contractor, a landlord or an insurer.

Our inspectors serve the whole city. We don't have a Toronto street address to list yet, so everything books by phone or through the form. These are some of the neighbourhoods on the map:

• Old Toronto: The Annex, Cabbagetown, Rosedale-Moore Park, Forest Hill, Trinity-Bellwoods, Roncesvalles, South Parkdale, High Park, The Junction, Liberty Village
• East York and the east end: Danforth, North Riverdale, Leaside, Old East York, The Beaches, Blake-Jones
• North York: Willowdale, Lawrence Park, Parkwoods-O'Connor Hills, York University Heights, Weston
• Etobicoke: Mimico, Long Branch, Kingsway South, Markland Wood, Rexdale
• Scarborough: Bendale, Clairlea-Birchmount, Scarborough Village, West Hill

Outside the city, the census tells two very different stories, and they change what we'd test first.

Source: Statistics Canada, 2021 Census Profile, occupied private dwellings by period of construction, structural type and tenure.

Elsewhere in the GTA or further east? Our service areas page lists every city with its own page, and a quick call will settle the rest.