Measuring up new bay windows, did fitter get it wrong ?

[AlbanyWA]

Looking for a general opinion, I'm replacing my bay window (centre and two sides) and got a quote from a local firm who are well established in my area with good recommendations, so I got the quote back, which I think is fair, but when I looked at the measurements once the new boxes are in there will be a gap of 50mm between side of box and brick reveal at either end of the side windows, they have said they would fit 2x4 timbers down the side and fix to that. and close up with foam. To me this is odd by not just build the new box and frames to current dimensions and maintain the existing 10-15mm gap either side. The windows are to be double glazed timber sashes and box will be 145 compare to 125mm for existing.
Sorry for going on a bit, but is this standard practice for made to measure windows, since there reason was their box faces are 90mm hence the gap.

 

[mattylad]

Ask the local firm why.

 

[freddiemercurystwin]

You also need to check if the new bay window requires bay poles, which are steel support posts that sit inside the corners and support whatever's above.

 

[AlbanyWA]

@mattylad: I fully intend to ask them why, because it makes sense on one level, easier job to fit for them, but what benefits for me
@freddiemercurystwin : I've added some pictures of inside and out, the side stone colunms have chem anchors at 300mm all the way down to damp course and the lintel is anchored with lateral restraints into joists. I'm not sure if windows perform support action so another question for them.

Thanks for your inputs

 

[AlbanyWA]

Well I got the answer, a mixture of their manufacturing process in having face panels a standard 90mm wide, saves on build costs probably, and the use of timber liners to get a plumb fit without trying to go into brick reveals since can't see the state until boxes come out, overall I'm happy with it so will see how they progress in coming months, whilst I get on and knock out the flat roof and put up a pitched one. Also no bay poles, timber above window appears to be resting on ledge, again one to check when box comes out, will have acros supporting just in case. Thanks for your inputs fellows.

 

[Koolpc]

Seems a shame if you are removing that bay.....

 

[AlbanyWA]

@Koolpc: Just the windows are coming, but the flat roof is a mixture of deeply cracked/fissured mortar and painted bitumen, so I think I'll get a better look knocking the top off, level out the edges and put up a double hipped bay roof

 

[Koolpc]

Ahh, glad its just the windows!

 

[mrrusty]

I think you also need to consider if the new windows don't go as deeply in to the reveal you are going to have a lot of frame visible which will change the appearance.

Box sash windows are designed to show minimal frame down the sides. You may well find on the back of the pillars there is no brick reveal at all - the boxes of the windows actually touch - certainly that is the case with mine. When I made mine up it was a bit of a devil to draw up and make up the measurements, and I actually chamferred off the back corners of the boxes to get the proper fit.

 

[AlbanyWA]

@mrrusty: That was on my mind, but can only trust the process, and on the day all will be revealed.