The Best Windows & Doors in St. Thomas

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The Best Windows & Doors in St. Thomas

London, Service Representatives - Clera Windows & Doors

Our London Team

Our local St. Thomas team has been serving London for over 45 years!


Contact us for more information and about a free quote!

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Our Local Clera Branch Serves St. Thomas

As the manufacturers and installers of all our windows and doors, we stand behind our work.

London, Service Representatives - Clera Windows & Doors

Our London Team

Our local St. Thomas team has been serving London for over 45 years!


Contact us for more information and about a free quote!

Contact Us

Our Local Clera Branch Serves St. Thomas

As the manufacturers and installers of all our windows and doors, we stand behind our work.

Clera Windows + Doors

St. Thomas

Toll Free: 1-844-738-7936
Phone: 1-844-738-7936
Fax: 905-738-0586


Clera Windows + Doors

Toll Free: 1-905-738-1870
Phone: 1-905-738-1870
Fax: 905-738-0586


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Best Windows And Doors - Clera Windows + Doors

Get over

$325 per Window

in FREE factory upgrades

With our wide range of ENERGY STAR products, you can be sure to save big on your next dream project!

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Limited Time Offer To Upgrade Your Home - Clera Windows + Doors

The Best Windows & Doors in St. Thomas

With close to 40 years in the industry, Clera offers the best doors and windows in St. Thomas and the surrounding areas. Our family-run business has been recognized by HomeStars, Canada’s Best 50 Privately Managed Companies, Best of Houzz, and the City of Vaughan’s Company of the Year.

Since 1978, we have been designing, manufacturing, and installing custom doors and windows across Canada, reaching clients in every corner of the country thanks to our more than 40 sales and installation offices scattered across the country.

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If you want quality replacement windows and doors with faultless service from design through to installation, then look no further than Clera Windows & Doors. Clera has been looking after the residents of St.Thomas for several decades, beautifying their homes and businesses. Our company works on the twin principles of the best quality goods with an attentive and supportive service which can supply the customer with exactly the product they are looking for.

Clera is well known for its craftsmanship and that’s because all our windows and doors are made at our own factory in Ontario. Our attention to detail is exceptional and we can provide you with exactly what you want for your St. Thomas home or business as each order is bespoke and tailor-made. Because we control the entire production process and do not buy in from third party suppliers, our costs are very reasonable. Enjoy great value for money and Clera’s lifetime warranty which comes as standard with all our windows and doors in St. Thomas.

Customized Windows & Doors In Alliston - Clera Windows + Doors
Invest In Your Home Today - Clera Windows + Doors

Why Choose Clera

Why take a chance with other window or door companies that purchase their products from another supplier, only to resell them to you for a higher cost?

Clera Windows + Doors is one of Canada’s largest, oldest, most dependable and reputable vinyl window manufacturers in Ontario. We fully manage and take care of your door and window replacement project from start to finish, ensuring every stage of your window or door project meets our lofty standards of craftsmanship.

Why are we Ontario’s most awarded window and door company?

The Clera Care Guarantee Logo

Over 45 Years of Experience

With over 45 years of experience, we have earned a reputation as one of Canada's leading window and door manufacturers and installers.

Certified Technicians Icon

Certified Technicians

You can trust our team of factory trained technicians to install your new windows perfectly—our A+ BBB rating is no accident!

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Serving Ontario With over 40 Branches

We have over 40 branches across Ontario, which means that we're always close by when you need us.

Non-prorated Lifetime Warranty Icon

Non-prorated Lifetime Warranty

Whenever anything goes wrong with your windows, we'll take care of it for you—no questions asked.

Energy Star Icon

ENERGY STAR® Certified

Our hung windows meet Canada's strict energy-efficiency standards. A window from Clera is not only high-quality and durable, but also energy-efficient.

Reasons to Love
our Products

Clera Windows + Doors is a reputable vinyl window manufacturer in Ontario with a history of dependable and high-quality products. Our superior materials and cutting-edge technology ensure durability, energy efficiency, and style. We offer customizable styles and colors, as well as superior security features and noise reduction technology to provide the best possible product attributes for your home.

Our team manages every stage of your replacement project, from start to finish. We work closely with you to understand your specific needs and preferences, and use our extensive experience and knowledge to deliver a solution that exceeds your expectations. Trust Clera Windows + Doors for exceptional service and expertise for your home renovation needs.

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Energy Star Icon

Energy Star Approved

Effortless Operation Icon

Modern, Contemporary Design with more glass, and less frame

Better Home Security Icon

Better home security

Noise Reduction Icon

A quieter home; improved noise reduction from the outdoors

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No Maintenance Icon

No maintenance: vinyl windows are virtually maintenance-free

Pilkington Low-e Glass Technology Icon

Pilkington Low-E Glass Technology, engineered specifically for Canadian climates

Structural Integrity Icon

Wet-glazed frames and sashes on all windows; the ultimate in protection against water and wind infiltration, with added structural integrity

Improved Ventilation Icon

Triple-fin weatherstripping with built-in anti-microbial properties, meaning no mould and better air quality

Pure Virgin UPVC Icon

100% pure virgin UPVC, providing protection from fading

Exceptional Durability Icon

Stronger hardware and structural integrity thanks to integrating galvanized steel (allows for larger, more spectacular views!)

St. Thomas Leading Replacement Windows & Doors

The perfect thing about Clera’s replacement windows and doors in St. Thomas—other than the cost, of course—is that you don’t have to fit your design needs and requirements into a pro forma pattern, you can tweak and adjust to your heart’s content as everything is handmade. Let our experienced and creative team steer you through to the final outcome of your dreams.

All of our range is top quality so your home or business will not only look good but increase in price. Replacing windows and doors in St. Thomas is one sure-fire way to add monetary value to the fabric of your home or business. Easy to keep clean, Clera windows and doors never fail to look good. We use the latest engineering technology in our Ontario factory to ensure a perfect fit and the best energy efficiency, benefiting your pocket. Well fitting doors and windows also offer privacy, safety and noise reduction. Enjoy a warm, secure, and peaceful environment courtesy of Clera.

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Window & Door Assemblers - Clera Windows + Doors
Best Vinyl‍ End Vent Slider Windows  - Clera Windows + Doors

Our range of glass, including speciality glass, grilles and colours will have something for everyone. If you can’t see what you want then we can personalise shades and tones to work with the theme for your St. Thomas home. Our paint features unique colour retention technology so your replacement windows and doors in St. Thomas will look as spick and span years down the line as when they were first fitted.

Browse through our comprehensive range of styles. Choose bow, bay windows, high profile and low profile for whatever best suits your home. Clera has a handy feature on the website where you can try out different looks and finishes to see what might best suit your property. In three simple steps, just choose, glass, grille and colour and the computer will do the rest. The design tools are easy to use and will help you narrow down the best choice of windows and doors.

Vinyl Windows & Doors

Here at Clera, we believe that the best material to craft good looking long-lasting replacement windows and doors is vinyl rather than wood. Years of experience and successful results for our customers has certainly proved us right.

Vinyl is very competitively priced and will provide a finish that looks as good as wood but is much tougher and long-lasting. It is very lightweight providing easy to move windows and doors, ideal for people who can’t or don’t want to struggle with traditional heavy fittings. Vinyl’s tip-top finish means less cleaning and maintenance for you. It has a high R-value so insulates perfectly to maintain draught-free consistent temperatures throughout your home and a saving on your heating bills.

Vinyl Windows & Doors - Clera Windows + Doors
Bay & Bow Windows - Clera Windows + Doors

Clera’s team of professional and experienced fitters will install your replacement windows and doors in line with the guidelines laid out by the Canadian Standards Association. Disruption is kept to a minimum with our ‘no fuss no mess’ approach leaving you to enjoy your beautiful new doors in St. Thomas confident with a lifetime guarantee for all component parts. Make your home beautiful with Clera.

At Clera Windows and Doors, we offer a wide range of custom vinyl windows featuring Low-E glass and Energy Star certification. What this means is that our products meet the rigorous standards imposed by Energy Star with regard to energy efficiency. Our Windows have surpassed the standards for heat-loss and air leakage, as well as for solar gain.

The Energy Star certification makes our windows ideal for the primarily cold St. Thomas Climate. Our products lose heat at a slow rate, reduce air leakage, and maximize solar gains, all of which ultimately reduce your energy bills and make your interior space more comfortable.In addition, we custom design and manufacture your vinyl windows using our optimized technology, get our skilled and professional installers to put them exactly where you want them to be, and then offer a lifetime warranty just for your peace of mind.

Our vinyl window styles range from fixed to sliding, bay and bow windows, casement and awning windows to specialty custom windows, so you are guaranteed to find a style that suits your home.

Extensive Range Of Vinyl Windows - Clera Windows + Doors
Serving Aylmer For Over 40 Years - Clera Windows + Doors

Serving St. Thomas For Over 40 Years

Ask around in St. Thomas and most people will recommend Clera. We have been supplying the local residents and offices for nearly 40 years. Our hard-won reputation for quality and service is something we value and cherish and strive to maintain.

Clera is a family business and family values are at the heart of everything we do from design right through to fitting. Hard work, integrity and a fair price are our mantras. Enjoy our superb workmanship at a very competitive price – your new doors and windows will be the envy of the neighbourhood.

St. Thomas residents are familiar with tough Canadian winter weather. We can reassure you that all items are stress tested and personally inspected before they leave our factory. Enjoy quiet living with a lovely consistent warmth throughout your property whilst you watch your energy bills tumble. Not only do we want to save you money but Clera is environmentally conscious too. All our furniture is Energy Star Certified so you are doing your bit to help the planet.

We are experts when it comes to getting replacement doors and windows. So when you approach us with your concerns, we will address your case individually, as everyone’s needs are unique.

Our professional team will discuss your likes and dislikes about your existing windows, and help you narrow down exactly what you expect from your new, vinyl energy-efficient windows. Our experts will examine your home or building to check for moisture intrusion or water penetration problems, after which we will establish whether replacing your windows and doors in St. Thomas will solve the problem.

Professional Installers - Clera Windows + Doors
Meet The Team - Clera Windows + Doors

Meet The Team At Clera Windows & Doors St. Thomas

Ignore the rest and go with the best, Clera, who has an unbeatable reputation for quality, price and customer service. Friendly and approachable, it is not for nothing that Clera is known as ‘the people’s company’. If we can supply the replacement windows and doors of your dreams, at a good price to enhance your home or business, then we have done our job. We do not outsource any of our production, every item is handmade in our Ontario factory.
Why not contact Clera for a free estimate without obligation. Take a trip to your nearest Clera outlet in St. Thomas and meet our friendly team who will happily help you on the road to the look you have always dreamed of for your St. Thomas home.

All our Energy Star approved doors in St. Thomas feature unique combinations of glass and panel designs, as well as high quality hardware. From our enduring exterior door systems made from fibreglass or steel to the custom sliding French, sliding patio, and storm doors, we make sure that our doors have superior water-penetration resistance and install them professionally so they can withstand the elements.

Clera Windows and Doors is a recognized brand in the industry, with a strong commitment to customer satisfaction. We have managed to achieve this by consistently delivering only the finest quality products and hiring and training competent installers.

For peace of mind on your next home or office improvement project in St. Thomas, come see Clera to view our selection of Canadian-made products and talk to our professional team to see how we can be of service to you.

Best Options For Your Replacement Doors And Windows - Clera Windows + Doors