Will this ready-made uPVC window fit?

[Sprogginz]

I've got two small windows that need replacing in a garage.

From brick to brick, the width measures 645mm with about 5mm difference at certain points.
The height measures 1080mm which includes the window sill.

I've seen these cheap windows in B&Q that measure 610mm x 1040mm.

Are they too small to fit properly?
I know you can get frame extenders but they might be too big for these excess gaps.

It would be really nice if I can get them to fit being so cheap and they are just for a garage after all.

Thanks very much and hope you can help.

 

[RandomGrinch]

Hi,

I'm just a DIY'er so feel free to ignore!

Heightwise, I would consider laying a new mortar bed to bring the tolerances closer - not a big job.

On the sides, I think the slimmest frame extender I have seen is 20mm, so only one per window would be needed, but this may look a bit odd!

Otherwise, for a gap that small, you could pack the frame out at the fixings, fill with foam and add cover trim.

As you say, it is only a garage!

 

[ronniecabers]

you could always just buy and cut the plastic frame extenders ( addons ) down so as to fill the excess gap. I think just fitting and filling with foam, then covering a 17.5mm gap either side is a bit of a bodge really....

 

[RandomGrinch]

you could always just buy and cut the plastic frame extenders ( addons ) down so as to fill the excess gap. I think just fitting and filling with foam, then covering a 17.5mm gap either side is a bit of a bodge really....

Yes good point. Cutting down the extenders didn't occur to me, as I thought they may lose some structural integrity.
And yes, definitely a bodge! But I've seen worse done by some 'Pro's'

 

[Sprogginz]

Thanks but what do you mean by cutting the extenders? As RandomGrinch mentioned, 20mm seems to be the thinnest. Did you mean cutting the protruding grooves down?
I thought about getting some plastic trim which is usually about 6mm thick so if I doubled up on that then that should do it but wasn't sure if that could affect the windows in any way.
Thanks again.

 

[crank39]

RG meant cutting the 20mm down the middle to get 10mm, cutting the ribs off can help but I don't think it'd get you enough.

What hasn't been said though is the length of the cill, ideally it's wants to be 100mm longer than the width of the window, a cill that is only as long as the window looks rank if you've added extenders to each side, it gives the impression the cill is too short and makes it look obvious the window is narrower than the opening

 

[Sprogginz]

Won't cutting the extenders down the middle compromise the sturdiness?
I see what you mean about the length of the sill. Might just have to bite the pillow and get the extension covers otherwise the cost will start creeping up.
No one can see the windows anyway as they're about 50cm away from a 6ft wall.
Thanks.