Can a new window be fitted entirely from inside?

[anonymous-user]

We still have a rattly single-glazed window in a small bedroom, which has very limited access from the house exterior - possibly explaining why it's not been upgraded in the past!

Is it therefore possible to fit a 'bog-standard' UPVC double-glazed window from the inside of the house only? It's only a small window - about 100cm square.

[brrapp]

Anything is possible but how easy it will be will depend on the construction of your walls and the type of window you use. Most houses in Scotland are built with the hole in the outer wall slightly smaller than the hole in the inner wall so that windows are almost always fitted from the inside. Most houses in England have the hole the same size all the way through so the windows can be fitted from the inside or outside but are mostly done from the outside. In most cases the window is made slightly smaller than the hole and the ingo/rebate is made up after window installation to fill the gap. This can be done with a trowel finish (cement mortar outside, plaster inside) or some kind of plate (timber, plastic etc).If yours is a standard English construction, I'd be looking at taking out the old window then narrowing the outer part of the wall first with a plate then fitting the window up against that from the inside.
Whatever is used, you'll still need to seal(silcon mastic) round the window frame from the outside which will be difficult with no external access but not impossible if you use a fully reversible sash which will allow you to open the window and seal it from the inside.

Edited by brrapp on Friday 30th December 15:28

[anonymous-user]

Thanks brrapp - I forgot to mention the wall is olde-worlde 9" solid brick construction, and window type is unimportant...

[deeen]

brrapp said:

...
Whatever is used, you'll still need to seal(silcon mastic) round the window frame from the outside which will be difficult with no external access but not impossible if you use a fully reversible sash which will allow you to open the window and seal it from the inside.

Or if you're fitting a plastic frame with a sealed unit, get an internally glazed one so you fit the frame first, lean through the frame to seal outside, then fit the sealed unit.

[Spudler]

In short, yes.
Fit frame, gun up, glaze.
Easy for a fitter, bit of faffing for a diyer.

[brrapp]

280E said:

Thanks brrapp - I forgot to mention the wall is olde-worlde 9" solid brick construction...

In that case , as above, I'd be looking at taking out the old window, fitting a bead of some sort all the way round just inside the opening, then fitting the new window up against the bead from the inside. If the window sash is fully reversible, you should be able to reach out from inside and seal round the gap between the frame and bead although if at all possible, reaching from a ladder or similar it would make it simpler and neater.

[paulwirral]

As above but in easier to understand for a novice language , order internal beaded frame that's 5mm smaller all round than the hole , fix it in with wedges then use fixing foam all round the frame to brickwork gap , then glaze it when the foam is set .

[anonymous-user]

Thanks for the helpful replies, chaps

The window is at the back, and all but hidden from view - so appearance isn't that important. The rest of the windows are double-glazed, so I'm not sure why one was left untouched

Anyways, it's one for the warmer weather, methinks!

Happy New Year, all

[Little Lofty]

If it's in a bedroom it should ideally be an escape window. A bigger opening will also help with cleaning.

[Pheo]

My fitter did this with a large 1.8m wide, 2.4m tall window in our spare room without major issues.

[dazwalsh]

Yeah its easy, old window out, feed the new window out through the hole and pull it back into position, wedge into place. fix in place with foam and screws. Pop yout gead out and seal the exterior with frame sealant and then glaze. The frame without glazing is very light so easy to handle.

[Pothole]

280E said:

T The rest of the windows are double-glazed, so I'm not sure why one was left untouched

Possibly because the previous owner wasn't on PH?

[dazwalsh]

dazwalsh said:

Yeah its easy, old window out, feed the new window out through the hole and pull it back into position, wedge into place. fix in place with foam and screws. Pop your head out and seal the exterior with frame sealant and then glaze. The frame without glazing is very light so easy to handle.

[anonymous-user]

Always easier with a pic ,
I wondered about this until I helped a builder pal & another window fitter pal, both bad jobs, one over a big conservatory and another over a large pitched roof. Both were "fitted" from the inside which I hadn't even considered