New windows/doors after insulation wrap

This is it

Evening all,

We bought a house last year which is already wrapped which is great, unfortunately the old PVC windows weren't upgraded at the time.

My question is, is it a huge problem to retrofit windows?

10-10-20

Depends on what you define as a huge problem. :)

If your OK with the internal reveals being knocked out and then reinstated, then you could retrofit that way. If the original windows were left in position at the inner-side of the outer leaf and not pushed further outwards to the threshold of the new insulation, then the new windows should be pushed outwards so that they follow best practice and close off the cold loop at the reveal.

So yes, it's a big job but one which is important to get right. That might require that you have both an experienced builder as well as a patient window installer so that the air-tightness is completed in full, as most or all window installers refuse to engage in applying air-tightness tape and see it a the builders job to do so.

This is it

Thanks for that! Yes, looks like the original windows were left in place so would need to be moved out.

Another house around the corner from us have just had the wrap done and it looks like the windows were left in the original position. Seems to be fairly common unfortunately, even if the wrong method

10-10-20

https://www.boards.ie/discussion/comment/122196642#Comment_122196642

It's common because it's less hassle and cheaper. It's an easier sell too if you're not into having plasterers redoing the reveals, so I can understand how it happens, but it's just not in the true spirit of doing the job properly!

Inviere

https://www.boards.ie/discussion/comment/122197095#Comment_122197095

In layman's terms then, is it a much bigger job to replace the windows after the wrapping is done?

10-10-20

https://www.boards.ie/discussion/comment/122197132#Comment_122197132

To get it retrofitted properly? Yes.

Window installers are likely to offer to carry out the job by mounting the window frames into the existing orifice as opposed to mounting them into the EWI as they should be. That usually means using expanding foam between the window frame and the reveal and often doesn't close the insulation to the same quality as it would had the windows been pushed outwards during wrapping. It also likely exposes more window-frame to the exterior than if the window has been fitted properly, a concern as the frame area has a higher heat-loss than than triple-glazing, so you're then getting a thermally less-effective windows as well as less effective reveals.

Then the cill has to be retrofitted and sealed to match the new window, the risk there is with damaging the existing finish or ending up with a less effective solution.

That why when you're wrapping you really need to be looking critically at the extincting windows and if they're under spec, costing the replacement of them into the overall project scope.

Here's a UK link and image showing how it should be done:

https://retrofit.support/detail/73/

Inviere

https://www.boards.ie/discussion/comment/122197264#Comment_122197264

Thanks for the info. A family members home was recently externally wrapped, done via SEAI grant. The existing windows were left in place (I think an initial assessment was done and perhaps they didn't warrant replacing?), but they are getting on in age (they're pvc double glazed, but must be getting on towards 20 years old.)

They're a Bay Window type at the front of the house. Probably should have replaced them beforehand, but I wasn't aware it wasn't the usual out with the old and in with the new scenario.

10-10-20

https://www.boards.ie/discussion/comment/122197317#Comment_122197317

Ah, bay windows may sometimes be the exception due to structural elements within the frames or cost, or maybe even complexity around the internal reveal or detailing concerns brought up by the client. Who knows. It's a compromise in many ways, the EWI may have been financially unattainable if new windows were factored in.

Lumen

https://www.boards.ie/discussion/comment/122197264#Comment_122197264

Have you any idea how to find a company to do this properly?

I've been trying to get a wrap+windows project off the ground for years on and off, but neither architects, builders, nor window installers want to know.

Architects aren't interested because it's too big, too small or too technical a job, they say I just need a good builder (have gone to 3 or 4 different firms).

Builders won't quote without drawings, which I'm not qualified to do.

Window companies don't give a **** about any of this other than putting a window into a hole.

MicktheMan

https://www.boards.ie/discussion/comment/122212382#Comment_122212382

Have you any idea how to find a company to do this properly?

I know. It took me 4 years (2010 to 2014) to find the right builder to take it on. Shocking the number of so called insulation expert companies I had over the floor who hadn't a clue what thermal bridging is. Only really interested in doing a quick job, getting the grant and moving onto the next job.