Trim & Finish Carpentry
Window Trim & Casing
The short answer
Window trim is the casing around a window plus the jamb extensions that bring the window frame flush with the wall, and — on a stool-and-apron detail — the sill and the trim beneath it. It is the most common trim work in Calgary right now because window replacement is widespread, and replacement windows almost always leave a deep unfinished reveal that needs new extensions and casing.
Part of our Trim Carpentry service.
The problem new windows create
Window replacement is extremely common across Calgary’s established neighbourhoods, where a great deal of housing stock is now reaching the point where original windows need replacing. The window installer removes the old unit, fits the new one, seals it and leaves.
What remains is a rough opening with a new window sitting somewhere inside it, and a gap between the window frame and the face of the drywall — the reveal. On a wall with modern insulation and exterior sheathing that reveal can be substantial.
Finishing it properly means fitting jamb extensions: pieces of material that bridge from the window frame to the plane of the wall, cut precisely because the depth is rarely consistent across the opening. Then casing is applied over the joint. Doing this well is what makes a replacement window look installed rather than inserted.
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We measure, draw and provide a fixed written price — no cost, no obligation.
The two casing approaches
- Picture-frame casing
- Casing on all four sides with mitred corners, like a picture frame. Clean, contemporary and simpler to execute. Now the more common choice in Calgary, particularly in newer homes and infills.
- Stool and apron
- A projecting sill — the stool — sits on the window opening with a trim apron beneath it, and casing runs down the sides to land on the stool. The traditional detail, appropriate in older homes and where you want a surface to place things on.
- Drywall return, no casing
- The reveal is finished in drywall with a corner bead and no wood trim at all. Minimalist and common in contemporary interiors. Requires a very clean drywall finish because there is no trim to hide anything.
Answers
Frequently asked questions
- Do I need new trim after replacing my windows?
- Almost always. Replacement windows sit differently in the opening than the originals, and existing casing rarely fits back cleanly. In most cases the reveal also needs new jamb extensions before casing can be applied. Some window companies include basic trim; many do not, and it is worth confirming what is in your window quote.
- What are jamb extensions?
- Strips of material that bridge the gap between the window frame and the interior face of the wall, bringing the two into the same plane so casing can sit flat. They are needed whenever the window is set back from the drywall — which is nearly always in a modern insulated wall assembly.
- Should I choose picture-frame or stool-and-apron?
- Picture-frame suits contemporary and transitional interiors and is cleaner and simpler. Stool-and-apron suits traditional and heritage homes and gives you a small ledge. Match whichever the rest of the house already uses unless you are re-trimming everything, in which case pick the one that suits the architecture.
- Can you trim a bay or a bow window?
- Yes, though they take considerably more time because of the angled joints and the wider seat board. A bay window seat board is effectively a small piece of joinery and is often built as one, particularly where it will be sat on or used as a display surface.
- What material should window trim be in a basement?
- For basement windows, particularly in egress wells where condensation is more likely, MDF at the sill is a poor choice. A moisture-tolerant material or a solid hardwood stool with a durable finish handles the condensation that forms on cold glass in a Calgary winter far better.
Why homeowners choose us
Careful work, honestly quoted.
We would rather talk you out of the wrong project than sell you one. Everything below is something you can hold us to.
Fixed written quotes
You get a drawing and a fixed price before anything is built — not an hourly estimate that moves.
Built for this climate
Material and joinery chosen for Calgary’s dry winters, so joints stay closed when the humidity drops.
Shop-built, site-scribed
Components made in a controlled shop, then scribed to your actual walls rather than trimmed to hide gaps.
One point of contact
The person who measures your space is the person accountable for the finished work.
Where we work
Calgary Carpentry serves Calgary and the surrounding communities.
Thinking about window trim?
Send a few details and we will come and measure. Free, no obligation, and a fixed written price.