window frame cracked after neighbor's building work

[petiteHBB]

Hello,

Our neighbors recently did some construction work and we noticed a few new/worsen cracks on our window frames/sill (please see the pics). There's clear cold air draft coming through. We were wondering how it should be repaired. Is silicon enough or it's better to ask for help from professionals.

Any advice would be very much appreciated! Thank you in advance.

Forgot to mention, the biggest crack is about 4-5mm.

How extensive was their building work, how close to your boundary and did they serve you with a party wall notice before they started?

Yes, they served a party wall notice and we hired a shared surveyor and got the schedule of condition. The work involved removing the whole chimney for loft conversion and some major changes (restructure the whole property: swapping the kitchen with bedrooms/living rooms and creating a new bathroom/kitchen etc). The cracked window is right next to the boundary and the surveyor confirmed that the damages are new and need to be repaired.

The neighbours always prefer to DIY. But we prefer to get it professionally repaired to avoid any future dispute. So we would like to know a bit more about it so that we can discuss with our neighbors about it without being like a fool 😅

Thank you for you reply! @tpmumtobe

Oh in that case I would get it done professionally - those look like large cracks, they're clearly caused by their works and they should have insurance/contingency funds in place to help cover costs. You don't want to patch it up with silicone only to find it fails and needs redoing in another year. This is exactly what the party wall award is for, I'd make use of it, don't let them fob you off with DIY.

I'd be more worried about what work they possibly did that caused that sort of remote damage and whether there is anything else more serious you can't see.

Has the window literally been shaken out of the window opening ? Do you know how they actually managed to do that ?

Something has clearly shifted significantly (and it might be walls rather than window frames). I wouldn't be happy with a DIY repair.

The uPVC window should be screwed into the brickwork, so on first glance it looks like the wooden internal surround/reveals have moved. This looks like the case with the picture from under the windowsill.
Open the window and look/check the brickwork outside for any issues.
At a guess, you can push/bang the wooden interior frame back towards the window.

Sorry for the late reply. Thank you all very much for the comments and suggestions! We'll discuss the repair with the neighbour later today, will see how it goes.

@tpmumtobe @Headstones250 Good to know about the insurance. Thank you both and we'll avoid the DIY work then hehe

@GasPanic That's also what we were worried. Also some damages may occur later, not sure how long they are liable for this. Maybe we need to ask the surveyor. I think the building work near the window was quite violent because they changed floor plan and had to move some walls. We could see the bricks through the cracks, it seems that the frame (sorry i don't the right term) is half detached from the wall. and yes you are right, @C4tastrophe we tried it and the interior frame can be easily pulled out and pushed in 😂