How to Choose a Window Company in Ontario

Ask whether the installers are employees of the company or contractors hired for the job. It is the single most useful question on this list.

The reason is accountability. When the installer works for someone else, a callback years later involves at least two companies deciding whose responsibility it is. When the installer is an employee, there is one company and one phone number.

The answer also tells you about training and coverage. Employees are trained on that specific product line, are covered under the company’s Workplace Safety and Insurance Board (WSIB) account, and can be held to a standard the company controls.

A strong answer. The company names its own crews, confirms they are employees, and can tell you they are WSIB covered and trained on the product they are installing.

A vague answer. “We work with a trusted installation partner,” or “our crews have been with us for years” without confirming they are on payroll.

At Centennial, every install is done by our own trained technicians. We do not hire subcontractors, and installation is included in the price rather than quoted separately.

Who makes the windows, and where?

Ask who manufactures the product and in which facility. Many companies selling replacement windows in Ontario are dealers rather than manufacturers.

There is nothing wrong with a dealer model on its own. It does change who you are dealing with when something needs attention. A dealer sells you a product built by a third party, which means the company that made it, the company that sold it, and the company that installed it are three separate businesses.

Manufacturing location matters for a practical reason too. Every opening in an older Ontario home is slightly different. A company building to your measurements can accommodate unusual sizes, century home proportions, and shapes a volume supplier will not produce.

A strong answer. A named facility, a named location, and a clear statement that the company builds what it sells.

A vague answer. “Canadian made” with no facility named, or a brand name that turns out to belong to a supplier rather than the company quoting you.

Centennial manufactures every window and door in a single facility in London, Ontario. One plant, one company, custom built to your openings.

Does the warranty cover the installation or only the product?

This is where quotes diverge most and where homeowners look least closely. Ask specifically whether labour and installation are covered, not just the product.

Warranty language across the category has converged. Terms like lifetime, non-prorated, and transferable now appear in almost every brochure, which makes the wording close to useless as a comparison tool. Scope is what still varies.

Read for four things. Whether installation and labour are included or only components such as hardware, glass, and seals. Whether coverage is pro-rated, meaning it pays a declining share over time. What the transfer rules are if you sell the home. And whether doors carry the same term as windows, because they frequently do not.

A strong answer. The company states plainly what is covered, for how long, and under what conditions, and hands you the document rather than describing it.

A vague answer. A single word like lifetime with no definition of whose lifetime, or coverage described only in conversation.

Our No Fine Print Warranty covers both the product and the installation for as long as you own your home, with no pro-rated terms. If you sell within 10 years, the coverage can transfer once the new owner contacts our head office directly. That precision is deliberate. A warranty you can read in full before signing is the only kind worth comparing.

What happens when I need service in year six?

Ask who you call, how long a response takes, and whether the company employs its own service technicians.

Post-installation service is the weakest point in this category. It is the part of the experience that arrives long after the sale, which is exactly why it is the part that gets quietly under-resourced. A warranty is only as good as the department that answers the phone.

There is a practical follow-up worth asking. Does the technician who attends the home work for the company that built the product? A technician servicing a product their own company manufactured knows the hardware, the sealed unit, and the install method without needing to look it up.

A strong answer. A dedicated service department, a direct number, and technicians on staff.

A vague answer. A general customer service line, or a promise that service requests are passed along to the installer.

Centennial runs a dedicated service department staffed by technicians who know the product because we built it. A service visit is scheduled at a time that suits the homeowner, and the same company that made the promise is the one that shows up.

Thinking about entry doors as well as windows? See our full range of exterior door systems, including fibreglass, steel, French, garden, and sliding.

Is the company insured, and for how much?

Ask for the liability coverage amount per jobsite and confirm WSIB coverage for everyone who will be on your property. Almost nobody asks this, and it carries real financial exposure.

Window and door replacement means open walls, ladders, lifting equipment, and work at height on your home. If a worker is injured on an uninsured jobsite, or if the structure is damaged during the work, the question of who pays does not resolve itself politely.

Coverage amounts vary widely across the category, and some smaller operations carry the minimum their broker would issue. A company that answers this question immediately, with a number, has thought about it before you asked.

A strong answer. A specific dollar figure per jobsite, confirmation of WSIB coverage, and a willingness to provide certificates on request.

A vague answer. “We are fully insured,” with no amount attached.

Centennial carries a minimum of $5 million in liability insurance per jobsite, and all crews are WSIB covered.

What does ENERGY STAR® certified actually mean here?

Ask what the certification covers and what the product is being compared against. Efficiency language is the easiest place in a quote to sound impressive without saying anything.

ENERGY STAR® is a certification administered in Canada by Natural Resources Canada. It is not a marketing term a company can apply to itself. A certified window is approximately 20% more efficient than an average window, and a certified door approximately 15% more efficient than an average door. Those baselines matter, because a percentage with no comparison point attached does not mean anything.

Watch for one specific overstatement. Efficiency ranges well above 20% belong to the ENERGY STAR Most Efficient designation, which is a separate and much narrower category. Seeing that range attached to standard certification is a sign the copy was written loosely.

This is worth caring about. Windows, doors, and skylights account for up to 25% of the energy lost from a home, and in a province that runs through repeated freeze-thaw cycles, that loss concentrates in the months your furnace works hardest.

A strong answer. The company explains what certified means, names the baseline, and can point to third-party verification of its manufacturing.

A vague answer. Energy claims stated as bare percentages, or efficiency described as a feature of the company rather than a certification of the product.

Centennial’s manufacturing process is voluntarily audited under the Keystone Fenestration Certification Program, and we participate in CSA, NFRC, and IGMA standards. More detail on what ENERGY STAR certification means and on our certificates and standards is available if you want to read further before deciding.

How long has the company operated in Ontario?

Ask how long the company has been trading under its current name and how many homes it has worked in. Leave this question until last, because the answers above give it context.

Tenure on its own proves very little. Plenty of long-standing companies deliver mediocre work, and newer entrants can be excellent. What tenure does tell you is whether the warranty has a realistic chance of outliving the sale. Coverage that runs for as long as you own your home depends entirely on the company still being there in year twelve.

Installed volume is the more useful half of the question. A company that has worked in a large number of Ontario homes has encountered the openings, the surprises, and the older construction that turn up in yours.

A strong answer. A founding year, a figure for homes served, and a track record that can be checked against reviews and industry membership.

A vague answer. “Years of experience,” or a company history that belongs to a parent brand rather than the business quoting you.

Centennial has operated in Ontario since 1981, which is 45 years. We have installed over 500,000 individual windows and doors and served over 50,000 homeowners across the province. We are an ENERGY STAR® award recipient, hold an A+ Better Business Bureau rating, and remain family owned and operated.

What To Do With the Answers

Take the seven questions into every consultation and write the answers down while you are still in the room. Quotes that looked interchangeable on paper rarely look interchangeable once the answers sit side by side.

Then compare the numbers last rather than first. Price differences between quotes usually trace back to something in these seven answers, and the cheaper quote is often cheaper for a reason that appears years later rather than on installation day.

If a company hesitates on any of them, that hesitation is information. A business that owns its manufacturing, employs its installers, and stands behind both will answer all seven without needing to check.

You are welcome to put every one of these questions to us. Book an in-home consultation today and we will walk your openings with you and answer them in your own home.