GT Doors is proudly based right here in Whitby, Ontario — this isn't just another area we service, it's home. We've supplied and installed front doors, entry doors and sliding patio doors for homeowners across Whitby and Durham Region for over 20 years. Every project starts with a free, no-obligation in-home measurement, and ends with a door that's plumb, sealed and square.

Door Installation in Whitby — Done Right the First Time

A premium door installed badly performs worse than a mid-range door installed properly. Our installation includes accurate measurement of the rough opening (not the old door), full removal of the old unit, shimming and levelling, low-expansion foam insulation, exterior flashing and caulking, and haul-away of your old door. Most front door replacements in Whitby are completed in a single day.

Fibreglass Doors in Whitby

Fibreglass is the most popular entry door we install in Whitby. It replicates natural woodgrain — stainable to look like oak, mahogany or walnut — without warping, denting, rotting or needing repainting, and it stands up to Ontario's freeze-thaw cycles. Browse our fibreglass doors or read our steel vs. fibreglass comparison to see which suits your home.

Steel Entry Doors

A quality insulated steel door is strong, secure, and the most affordable way to get a solid, well-sealed entry — a smart choice for front doors, side doors and garage-to-house doors. See our steel doors for current options.

Patio Doors & Sliding Glass Doors in Whitby

We install sliding glass patio doors built to glide smoothly for years — quality rollers, well-drained tracks, Low-E argon glass and proper locks. If your current slider takes two hands and a shoulder, or it's the coldest spot in the house, it's time. Details are on our sliding doors page. We also install garden doors and French-style patio doors — ask us what fits your opening.

When to Replace a Door

Drafts around the frame, daylight at the edges, fog between the glass panes, a door that sticks or drags, a deadbolt that doesn't line up, rot or rust at the bottom third — if two or more of these show up together, replacement beats repair. We'll give you an honest answer at the free measurement, including when a doorglass swap is the cheaper fix.

Serving Every Corner of Whitby

Brooklin, Williamsburg, Pringle Creek, Rolling Acres, Taunton North, Whitby Shores, Port Whitby and downtown Whitby — plus Ajax, Oshawa, Pickering, Bowmanville, Clarington, Courtice, Scarborough, Markham, Stouffville, Uxbridge and Scugog.

Frequently Asked Questions

How much does a new front door cost in Whitby? It depends on material, glass and the condition of the opening — which is why we quote from a free in-home measurement rather than guessing over the phone.

How long does door installation take? Most replacements are done in one day. The lead time to build your door is usually the longer part — ask about it early.

Can you replace just the glass in my door? Yes, when the door itself is sound. If the slab is warped or drafty, we'll tell you straight.

Ready for a new door? Get a free quote or call 905-903-9598.