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An installer's honest checklist for hiring well
There is no single best window company in Ontario, only the right one for your home, budget and timeline. GTS Windows & Doors has installed and serviced windows and doors in Kitchener and across Waterloo Region since 1986, and this is the checklist we would hand a friend comparing quotes, including ours. We are licensed, insured and WSIB covered, and we hold our own crews to every point on this list.
We work for homeowners, landlords, property managers, builders and commercial owners from Guelph to Wilmot, so we know what a thorough quote contains and what a weak one leaves out. The companies that do this job well are easy to spot once you know which questions to ask and which documents to request. Good companies welcome those questions, because the answers make their quote easier to trust.
Below you will find the questions worth asking, the credentials you can check yourself in a few minutes, how manufacturers and installers differ, a short list of Canadian-made brands, and the red flags that should slow you down. None of it depends on hiring us, and all of it applies whether you are replacing one patio door or every window in an office building.
Ask every company the same questions and write the answers down. The real differences between quotes usually show up here, not in the headline price.
Reviews tell you how past customers felt. Credentials tell you what happens if something goes wrong, and most of them take only minutes to verify.
We carry WSIB coverage and liability insurance, we are a SAWDAC member, and we install ENERGY STAR rated products. We are happy to show the paperwork before you sign, and our customer reviews page links to our 4.5-star rating from 31 Google reviews.
Ask for a current Workplace Safety and Insurance Board clearance certificate, or look the company up with WSIB's free online clearance tool. Clearances run for set periods of up to 90 days, so check the date.
Homeowners hiring for their own residence are not legally required to collect one, but it is the quickest way to confirm the crew is covered.
Request a certificate of insurance showing the insurer, the policy dates and the coverage amount. Two million dollars in general liability is a common benchmark and the minimum SAWDAC sets for its dealer members.
Window installation is not a compulsory certified trade in Ontario, so there is no provincial installer licence to look up. Check instead for a registered business with a real local address, and ask how long its installers have been doing this work.
Any window sold as ENERGY STAR certified should appear in Natural Resources Canada's searchable product list, with its U-factor or Energy Rating shown. ENERGY STAR models are also a condition of the window and door incentive described on our rebates page.
The Ontario Building Code requires windows, doors and skylights to meet performance grades under the North American Fenestration Standard and its Canadian supplement, CSA A440S1. Look for the performance label on the frame, or ask for it on the product specification sheet.
The Siding and Window Dealers Association of Canada requires dealer members to have at least three full years in the renovation business, $2 million in liability insurance, workers' compensation as required by law, and a minimum 5-year workmanship warranty on renovation work. Members also agree to a code of ethics covering advertising, contracts and complaints.
Some window companies build their own windows and sell them direct, while others, like GTS, are installers who buy from manufacturers and focus on fitting the product properly. Both models can deliver an excellent result.
A manufacturer-retailer controls production and may offer one warranty covering both product and install. An independent installer can match the product to the house, choosing a fibreglass line for one job and a wood-clad unit for another, rather than selling a single factory's range.
Either way, many of the leaking and drafty windows we are called to look at trace back to the installation rather than the product. Ask who installs, how they were trained, and who comes back if a window leaks in year three.
Canada has a deep window and door manufacturing base, and several strong lines are built within a day's drive of Kitchener. The names below are examples of Canadian manufacturers sold through dealer networks, not a ranking and not a list of our suppliers.
Buying from a manufacturer close to home often means shorter lead times, easier access to parts years later, and a warranty contact in the same time zone. Ask any installer which lines they carry and why they chose them.
Material matters as much as origin. If you are weighing options, our guide to fibreglass windows explains where that frame type earns its higher price.
A price that expires tonight or a special discount for being a display home is a sales tactic, not a saving. If you sign a contract in your home, Ontario's Consumer Protection Act gives you 10 days after receiving your written copy to cancel without giving a reason.
A quote that says only install windows leaves out everything that decides whether they will leak. Look for full-frame or retrofit named per opening, plus flashing, insulation, trim and disposal.
Many lifetime warranties cover the glass or frame for the original owner only, with labour covered for a year or two at most. A lifetime promise that says nothing about installation labour is not the warranty it sounds like.
If the quote does not name the brand, series and glass package, you cannot compare it with anyone else's. It also leaves room to substitute a cheaper unit on delivery day.
A deposit to order custom windows is normal. Full payment before delivery, or a cash discount with no written contract, is not.
When one quote is far lower than the others, find out what is missing. It is often the install method, the glass package, or the trim and disposal.
A window warranty is really two warranties: one from the manufacturer on the product, and one from the installer on the workmanship. Ask for both in writing, with the length of each and whether labour is included.
GTS backs its installations with a 20-year parts and labour warranty. Our warranty details set out what it covers, so you can compare it line by line with any other quote on your table.
The best company for you is one that installs a certified product properly and stands behind it locally. Look for WSIB clearance, liability insurance, written product and labour warranties, ENERGY STAR listed products, itemized quotes and a steady record of reviews over several years. A company that ticks those boxes and answers your installation questions clearly is a strong choice.
Plenty. Examples include Loewen in Manitoba, Inline Fiberglass, Fibertec and Dashwood in Ontario, Kohltech in Nova Scotia and Ontario, and Novatech doors from Quebec and Ontario. Ask your installer where the specific product in your quote is built.
Three is a good number for most projects. Fewer makes it hard to judge price, and more tends to blur the details, so compare three quotes that name the same frame type, glass package and install method. Our cost guide shows typical local ranges to check them against.
SAWDAC is the Siding and Window Dealers Association of Canada, an industry association for window, door and siding contractors. Dealer members must meet minimums on years in business, liability insurance and workmanship warranty, and follow a code of ethics. GTS Windows & Doors is a member.
Put our quote next to the others and run this checklist on all of them. Book an on-site measure and we will give you a written, itemized quote to compare.
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