Retrofit vs full-frame window replacement: which does your house need?
There are two ways to replace a window, and the right one depends on what's behind your trim. Here's the plain comparison, which Island homes tend to need which, and how we decide at the measure.
The two methods in plain terms
Retrofit (insert)
The old sashes and glass are taken out, the existing frame stays in the wall, and the new window is fitted inside it and sealed. Outside, the siding isn't touched. Inside, trim is mostly left as it is. It's quicker and cleaner, and it's the lower price. It works when the frame is still sound, square and dry.
Full-frame replacement
The whole window, frame and all, is removed back to the rough opening. We inspect the framing and sill, flash the opening, insulate around the new frame, and set a new window in the wall. It's more work, it disturbs the siding and trim, and it costs more. It's the right call when something behind the old frame needs to be fixed.
Which homes need which
Every house is different, but there are patterns on the mid-Island.
- Homes with original aluminum frames (1970s to 80s): often full-frame. Aluminum carries cold and moisture, is rarely insulated around, and the sills below are often damp. Taking it all out is the fix. Drafty windows in these houses usually come from the frame, not the glass
- Homes with early vinyl or wood windows in decent shape (1990s): often a good retrofit candidate, provided the frames are square, solid and not rotted
- Any window with water damage: full-frame. A new window in a wet sill will fail early. Rain, salt air and constant condensation are what do this on the coast
- Homes with fresh siding or fine interior finishing you want left alone: retrofit, if the frame passes inspection
- Windows that are only foggy between the panes: often a retrofit, since the frame is the part that's still fine. See foggy windows
How we decide at the measure
This is what the free 45-minute visit is for. With a tape, a flashlight and a small probe, we look at the following for each window:
- The frame: is it square, solid and free of rot, or twisted, soft or corroded
- The sill and the framing underneath, for moisture or soft spots
- Whether the gap around the frame has any insulation in it
- The condition of the siding and trim, and what disturbing them would involve
- How much glass area you'd give up with a retrofit
Then we tell you which method each window needs and why, and write the price for each window on its own line. We don't sell a full-frame when a retrofit does the job. If we find rot, you'll hear about it before we touch the window, with a price for the repair.
What about the price difference?
In general terms, full-frame costs more than retrofit, because there is more labour, more finishing and sometimes repairs to the opening. How much more varies by window size, siding type and the condition of what's behind the trim, so we give you real numbers in writing after the measure rather than a guess here. For a ballpark before you book, the online estimate will do. The quote that follows is written line by line and good for 30 days.
Whichever method you need, the windows are the same: Thermoproof, made in Cobble Hill since 1977. You'll find the Nanaimo details on our Nanaimo page.
FAQ
Common questions
What is a retrofit window?
A retrofit, also called an insert or replacement window, is a new window that fits inside your existing frame. The old sashes and glass come out, the frame stays, and the new window is set in and sealed. The exterior siding and most of the interior trim stay as they are, so it's quicker and less disruptive.
What is a full-frame replacement?
Everything comes out, frame included, back to the rough opening in the wall. The opening is checked for rot, flashed, insulated and then the new window is installed. Siding and interior trim are disturbed and have to be repaired or replaced, which is why it costs more.
Is retrofit always cheaper?
In general, yes, because there's less labour and less finishing. Full-frame costs more per window. How much more depends on the window, the siding and the trim, so we price it line by line after the measure rather than guess. Online, our estimate tool gives you a starting range.
Does a retrofit window let in less light?
A little, because the new window sits inside the old frame, so the visible glass area is slightly smaller. On a large picture window the difference is usually hard to notice. On a small window it can be more obvious. We show you the actual glass size at the measure, before you order.
Can you do a mix of both in one house?
Yes, and it's common. A single house might have a sound vinyl frame in the living room that takes a retrofit, and a bathroom or north-wall window that has rotted and needs full-frame. We quote each window on its own, so you only pay for the heavier job where it's needed.