Most wooden exterior windows on Calgary homes do not fail suddenly. They fail slowly, at the sill, across years of freeze-thaw cycles — and the first sign is usually paint that will not stay put.
The useful question is not "are these old?" It is "has water got into the wood yet?" If it has not, the windows can usually be kept. If it has, no amount of repainting will hold, and every season you wait makes the eventual replacement more expensive.
Cossins Windows Ltd. has worked on Calgary homes since 1978. Our aluminum-clad wood window line is built for exactly this situation: real wood inside, a maintenance-free aluminum exterior, and proportions matched to the windows already on the house.
Do your wooden exterior windows need replacing? A five-minute check
You can answer most of this yourself, from inside, with a screwdriver and a torch.
Start with the sill. That is the horizontal member across the bottom of the window, and it is where water sits. Press the tip of a screwdriver into the wood at each end of the sill, roughly where it meets the frame. Then check the bottom corners of the frame itself.
- The screwdriver stops and the wood feels hard — the wood is sound. Repair is on the table.
- The screwdriver sinks in easily, or the wood feels spongy, or it crumbles — the wood is rotting. This is the one finding that decides the question.
Then check the paint on the exterior. Peeling or flaking paint is not automatically fatal. Paint fails before wood does, and a window repainted now may have years left. What matters is where it has failed. Paint lifting along the horizontal sill and the bottom corners means water is already getting under it. Paint failing on the sun-facing side, or high on the frame, is usually just UV.
Look for staining on the inside. Brown or grey stains on the interior trim, or a soft patch in the plaster or drywall below the window, mean water is getting past the frame and into the wall. A dark tidemark around the window reveal is the same message.
Check whether the sealed unit has gone. If the glass is foggy or has a milky film between the panes, the seal on the sealed unit has failed. On a window with a sound frame this is often good news: the sealed unit may be replaceable on its own, leaving the frame in place. Whether it can be depends on the frame construction and its condition, and we confirm that when we see the window.
Test the sashes. Open and close each one. A sash that sticks in July and rattles in January is swelling and shrinking with the seasons — annoying, and fixable, but it also means the frame is not sealed. A sash that has dropped, or a frame that is visibly out of square against the reveal, means the opening itself has moved.
The honest summary:
| What you found | What it usually means |
|---|---|
| Peeling paint, no soft wood | Keep them. Repaint and recaulk. |
| Fogged glass, sound frame | Keep them. Replace the sealed units. |
| Sticking sashes, worn hardware, draughts | Keep them. Adjust, re-weatherstrip, replace hardware. |
| Soft or crumbling wood at the sill | Replace. Rot spreads along the sill and into the frame. |
| Soft wood at the bottom corners, or staining inside | Replace. Water is already past the window. |
| Frame out of square, sashes dropped | Replace. The opening has moved; a new window will not fix that on its own. |
We will tell you which column you are in. If it is the first, the second or the third, we will say so, and that is a shorter conversation than you expected.
Why Calgary is unusually hard on wooden exterior windows
Wooden windows last a very long time in a mild, stable climate. Calgary is neither of those things, and it is worth understanding exactly what is being asked of them here, because it explains why a maintenance regime that works elsewhere does not hold up.
Freeze-thaw is what kills the sill. Water gets into a hairline crack in the paint or a joint in the wood. When it freezes it expands, which widens the crack. It thaws, more water enters, and it freezes again. Calgary runs through this cycle repeatedly every winter. It is the mechanism behind almost every rotted sill we see, and it is why the damage is always at the bottom, where water collects.
Chinooks attack the paint film. A chinook can move the temperature twenty degrees in a few hours. Wood and the paint on it expand and contract at different rates. The paint film is the more brittle of the two, so it gives first. Over the life of an original wood window in Calgary, that means a recurring repaint cycle rather than a one-time finish.
The sun is not gentle either. Calgary sits at altitude with intense UV. On south and west elevations, UV breaks down both the paint and the lignin in the wood underneath it. Those are the windows that always look the worst.
Interior winter air pulls the joints apart. Calgary homes run very dry inside from October to March. Wood shrinks as it dries, joints open, and warm moist interior air finds its way into the frame. That is how rot sometimes starts from the inside of a wall rather than the outside of a window.
Then there is hail. Exposed wood can dent, splinter and take on water. Cladding stands up to it substantially better, which is the point of cladding rather than a claim about any particular storm.
Put those together and the maintenance burden is not really "occasional painting." On a house with a significant number of original wood windows, the realistic pattern is a recurring full exterior repaint, ongoing caulking and glazing repair in between, and eventually rot repair on the sills and bottom rails. Most owners do not price that cycle in when they buy an older home — and it is a cycle, not a one-off cost.
The choice is not wood or maintenance-free
This is where most Calgary homeowners are given a false choice. The advice tends to arrive as: keep the wood and keep painting it forever, or accept a window that gives up the wood interior entirely.
There is a third option, and on a house of this type it is usually the right one. Aluminum-clad wood is a real wood window on the inside with an extruded aluminum shell bonded over the outside. The wood no longer stands exposed to weather, so it is not subject to the moisture and repainting cycle that unprotected exterior wood is.
What that buys you:
- The interior stays wood. Clear hemlock frames that can be stained or painted to match the trim already in the house. This matters more than it sounds, because the interior face is the one you live with every day, and a wood frame is what makes that face look and feel right.
- The exterior does not need painting. Extruded aluminum in six standard colours. It holds its finish far better than exposed wood, which is the maintenance burden cladding exists to remove.
- The window is built to your opening. Not a stock size trimmed to fit. Special shapes, oversized combinations and non-standard proportions are all part of the line.
- Alberta-grade glazing. Dual or triple-pane with Low-E coating and argon fill, warm-edge spacers, and an option for triple glazing on north-facing walls and the coldest exposures.
- Truth Encore hardware, which is what makes a window feel like a proper window when you open it.
And the line is manufactured in our own facility at 2908 18 St NE, so the person who measured your openings and the person who built the windows work for the same company. Cossins in-house installation crews fit them.
Will new windows look wrong on an older house?
This is the real objection, and it is a fair one. The fear is not about performance. It is that the house will stop looking like itself.
Three things decide whether that happens.
The proportions. Older homes were built to window openings in particular sizes and rhythms, and the window was set back in the wall by a generous amount. A deeper frame with a real shadow line is a large part of why an older house reads the way it does. Clad wood keeps the depth. Thin profiles lose it, and that is the single most common reason a replacement window looks wrong on an older façade.
The grille pattern and sightlines. The muntin or grille layout, the width of the frame members, the relationship between the fixed and opening sections — these are what the eye actually registers. We build to the pattern already on the house rather than to a default.
The colour. Six standard cladding colours, and the exterior of a clad window reads as a painted sash — which is exactly what is there now, minus the repainting.
None of that requires the house to be a museum piece. It requires matching what is already on the wall.
Wooden exterior doors have the same problem
If the windows on the house are wood, the exterior doors very likely are too, and they fail in the same way and for the same reasons — water at the bottom rail and the threshold, paint that will not stay put, and rot working up from the base.
We offer a full line of exterior doors and patio doors: metal-clad wood exterior and sliding patio doors on the same principle as the windows — wood inside, maintenance-free aluminum outside — plus fibreglass entry doors, which are highly resistant to warping, cracking, denting and rot, and sliding patio doors. Optional multi-point locking hardware engages bolts along the full height of the door rather than just at the handle, which matters for security and for keeping a weather-tight seal in a wind-driven Calgary winter.
Doors and windows are usually worth doing in the same conversation, because the same trim, the same colour and the same crew are involved. It is also worth doing in the same conversation for a less obvious reason: if the windows are being replaced, the interior trim is already off.
The Calgary neighbourhoods where this comes up most
Wooden exterior windows are not evenly distributed across Calgary. They are concentrated where the housing stock was custom-built in the pre-war and early post-war periods, which is precisely why this question keeps coming up in the same handful of communities.
- Upper Mount Royal — estate homes, many with original wood sash and generous window proportions
- Elbow Park — including heritage-designated homes where the façade pattern matters a great deal
- Rideau and Roxborough — older properties with original wood frames, often already on a second or third generation of windows
- Elboya — post-war custom homes with wood-framed units that have been through several repairs
- Britannia — the same era and the same pattern
- Upper Scarborough — early garden-suburb lots with wood windows that have been maintained, repaired and maintained again
What these homes have in common is not age for its own sake. It is that they were built with real wood windows, they are large enough that the window count makes the repaint cycle genuinely expensive, and their owners are not going to accept a window that changes the character of the house.
Heritage and character considerations
If the house carries a heritage designation, or sits in an area with design guidelines, the exterior appearance of the windows may be subject to review. In practice these reviews are about what the street sees: proportions, the grille pattern, the frame colour and the depth of the reveal.
That is a specification question rather than a complication. Because clad wood windows are built to your measured opening and we reproduce the existing profile and pattern, they generally satisfy the thing those reviews are actually concerned with — that the house still looks like the house. Where a specific approval is required, we will tell you it is required; we will not guess on your behalf, and we would rather you confirm it before anything is ordered.
How to compare wood window replacement quotes
Comparing quotes on this work is harder than it should be, because the quotes rarely describe the same job. Five things are worth pinning down before you sign anything.
1. Who measures, and who installs. Ask directly whether the company installing the windows is employed by the company that sold them. Cossins in-house crews install every window we supply, and we manufacture our window lines in Calgary. It means one organisation owns the measurement, the build and the fit.
2. What is actually included in the opening. A quote that covers the window but not flashing, sealing, trim and the disposal of the old units is not a cheaper quote. It is a partial one.
3. The glass specification, in writing. Pane count, Low-E coating, argon fill, spacer type. "Triple pane" by itself is not a specification.
4. Whether the frames are built to your opening or trimmed to fit. This is the difference between a window that sits properly and a window that needed encouragement, and it will show up as draughts within a few years.
5. Whether the quote has a fixed end date. A price that expires in two weeks is a sales mechanism, not a schedule.
Working with us
We have worked on Calgary homes since 1978, from our facility and showroom at 2908 18 St NE. The approach on a house with wooden exterior windows is deliberately unhurried.
We start with a Private Consultation at your home. We measure the openings properly, look at the condition of what is there, and work out how much of it genuinely needs replacing rather than assuming all of it does. If some windows are sound, we will say so and quote only what is needed.
If that leads to window work, you will see the specification in writing before anything is ordered, and you will know what your six cladding colour options look like against the house.
If it does not lead anywhere, that is a fine outcome too.
Book a private consultation and we will tell you honestly whether your wooden exterior windows need replacing, or whether they need a weekend of paint and caulking.
Common questions
How do I know if my wood windows need to be replaced or repaired?
Press a screwdriver into the wood of the sill and the bottom corners of the frame. If the wood is hard, the window can usually be repaired. If the screwdriver sinks in or the wood crumbles, the wood is rotting and the window should be replaced, because rot spreads along the sill and into the frame and no repainting will hold it. Fogged glass on its own is not a reason to replace a wood window — the sealed unit can be replaced while the frame stays.
Can you replace just the glass in a wood window?
Yes, and on a sound wood frame it is usually the sensible repair. If the glass is foggy or milky between the panes, the seal on the sealed unit has failed. The sealed unit is a separate component from the frame, so it can be removed and replaced on its own, provided the frame itself is sound. Whether that is possible on any given window depends on the frame construction and its present condition, and we will confirm it when we look at yours.
What is aluminum-clad wood, and why is it suited to an older Calgary home?
It is a real wood window with an extruded aluminum shell bonded over the exterior face. The interior stays clear hemlock, which can be stained or painted to match existing trim. The exterior face is aluminum, so it does not take on water the way exposed wood does and does not need repainting. That removes most of the moisture and maintenance cycle that damages an unprotected wood sill over time. It is the option that keeps a wood interior and a traditional exterior appearance without the recurring repaint.
Will new windows change the look of my house?
Not if the proportions, grille pattern and frame depth are matched to what is already there. Those three things are what the eye reads. Clad wood frames are built to your measured opening and can reproduce the existing profile, so the exterior reads as a painted sash in one of six standard cladding colours. The most common reason a replacement window looks wrong on an older house is a thin profile that loses the depth and shadow line of the original.
Do you have to remove the interior trim?
It depends on the existing frame and the installation method. Where a wood frame is sound and only the sealed unit is being replaced, interior trim is normally undisturbed. Full frame replacements involve more work at the reveal. We will tell you what is involved at the measurement stage, before anything is ordered.
How long does wood window replacement take?
It depends on the number of openings and whether frames are being replaced or sealed units only. A single sealed unit is a short visit. A whole-house window replacement is on site for longer, and the windows themselves are built to order after measurement. You will get a schedule in writing with the specification rather than a timeframe given verbally.
Can you match the grille pattern and proportions of my existing windows?
Yes. Grille layout, frame member widths and the relationship between fixed and opening sections are specified when the window is built, and we build to the pattern already on the house. Special shapes and non-standard proportions are part of the line, which is what makes this workable on a house that was not built to stock sizes.
My home is in a heritage area. Are there restrictions?
Possibly. Where a home has a heritage designation or falls under area design guidelines, the exterior appearance of windows may be subject to review, and those reviews generally concern proportions, grille pattern, colour and reveal depth. Because clad wood windows are built to your measured opening and the existing profile is reproduced, they are usually compatible with what those reviews are assessing. Where an approval is required, we will tell you it is required — we will not guess on your behalf, and we would rather you confirm it before anything is ordered.
Can you replace wooden exterior doors at the same time as the windows?
Yes, and on a house with wooden exterior windows the doors are usually failing for identical reasons. We offer metal-clad wood exterior and sliding patio doors on the same principle — wood inside, maintenance-free aluminum outside — as well as fibreglass entry doors and sliding patio doors. Optional multi-point locking hardware engages bolts along the full height of the door. Doing both at once also means the trim, colour and crew are dealt with in a single pass.
What happens during a private consultation?
We come to your home, measure the openings properly, and assess the actual condition of the windows already there — probing sills, checking sealed units, testing operation. We then work out how much genuinely needs replacing rather than assuming all of it does. If some windows are sound, we will say so and quote only what is needed. Book through the consultation page and we will bring the colour options with us.
Which Calgary neighbourhoods do you work in?
We work across Calgary, and a large share of our established-home window work is in Upper Mount Royal, Elbow Park, Rideau and Roxborough, Elboya, Britannia and Upper Scarborough — the communities where custom-built homes were fitted with wooden exterior windows and where the maintenance cycle has now come round. We also work throughout the city and the surrounding area.