Advice on neighbour's extension and impact on my property

[Wonderbug81]

My downstair's neighbour is getting an extension done directly beneath my flat. We have a party wall agreement for removal of two chimney breasts at their level but the two surveyors involved agreed no other PWA was needed.

Separately, one of my windows is in a room directly above where they're extending their kitchen into the garden, is no longer fully shutting. The handle won't close properly and it won't lock either. I've also seen some minor cracks around the frame.

I was assured the back wall wasn't being knocked down, they were just removing the double garden doors so no major work to that wall but they have done a lot of drilling so I'm not sure if that's created movement.

The surveyors took photos before the work but what else should I be doing now? And was this likely preventable?

The only thing I can think of would be take photos now and inform your neighbour in writing. Do you have the contact details of the party wall surveyors? In fact the party wall surveyor should have been chosen and appointed by you, not your neighbour.
You should also ask to see the insurance documents of the builder (which you should already have checked before any work started).
Did your neighbour need planning permission for the work? You should contact your local planning department to check.
I am very concerned that they are removing 2 chimney breasts as normally this would not be allowed.
Once you have done all the above you could contact your own building insurance company. But be aware that making a claim will increase your premiums, so you must check the builder's insurance policy first.
Finally, get onto this urgently as it sounds dangerous to me.

How are they removing 2 chimney breasts? Have they already been previously removed from your apartment?
For the window, contact the neighbour or your insurer.

Thanks. The chimney breast work is being overseen by my independent surveyor as well as the neighbour's. Photos were taken of my entire flat and building will be reviewed again by both when finished.

My surveyor (a PWA specialist) was comfortable with the chimney work. Not ideal for me but gave me some peace of mind.

But the surveyors agreed now PWA was needed for any other work. There is planning permission for the extension and I raised my concerns re my building at the time but these were more related to the type of roof etc they were putting on the extension. They haven't as far as I know knocked down any major walls at the back where my window is, just added new walls. That's why I thought it might be down to the extensive drilling and ground work. It's a Victorian house in case that's helpful.

Would prefer not to involve building or home insurance but might come to it.

If they have got planning permission you can contact your local council building inspector via their website. I don't think planning will help, but there will be an inspector responsible for coming out to look at the work from time to time, so you will need to read the blurb on the website. You probably won't get anywhere before Monday. Speak to the builder and the neighbour asap.

It definitely sounds like there has been some movement if your window no longer shuts.
Whether they’ve removed a wall or added an additional wall they can both cause movement whilst the building settles.
You need to tell your party wall surveyor what’s happened and your downstairs neighbour will have to pay to fix the problem.

This isn’t an issue for the planning department

Drilling won’t cause any issues. Using a Jack hammer might. Removing a wall or increasing the size of the bay doors opening could affect you. Ground work also. Old houses have very shallow foundations. However extension groundwork should not affect the back of the house. Maybe if the have excavated across the whole back of the house lowering the ground level, if may have had a temporary affect. As you have your own surveyor, talk to them.

I’m still interested in how they are removing chimney breasts downstairs if you still have them.

The neighbour appoints a party wall surveyor and the OP can a point a party wall surveyor too. OPs surveyors fees are met by her neighbour. If the two surveyors do not agree a third is appointed by their joint agreement ( the neighbour cannot disagree ) and the third surveyor is also paid for by the neighbour ie. the one carrying out the work.

I’d argue that the cracks and movement should fall under the PWA. It could have been caused by the removal of the chimney breasts, movement has widespread effects not just the bit directly above.

Ask your surveyor.

Hopefully the neighbours structural engineer will have specified a lintel to hold up the existing chimneys. That’s the normal course of action.

Lintels need to sit on something. Maybe they are long steels? Expensive way of doing it.

That is what I said. It isn't the responsibility of planning, but the council will have building inspectors who come to look at the work at intervals during construction to ensure they conform to regulations. As the project required planning permission, there will be a local authority building inspector who knows about the project (and will want to make sure the lintels are in place).

@Wonderbug81 I would be worried about movement if windows no longer close properly and I would be really concerned if they are removing chimney breasts unless you have previously removed your chimney breasts and the chimney onthe roof and in the attic!! that could be disastrous!

Thats building control and tbh a lot of councils outsource that now.
( Which is proving to be a huge problem.)

It is expensive yes but that’s the only way of holding the chimney up.
The lintels basically bracket out from the party wall

Sounds like you are talking about a Gallows Bracket. My knowledge of lintels are they are long and straight and must be supported adequately on each end
They could also corbel the brickwork. Or put a steel in the length of the room, sitting on a wall either end, with the chimney resting on it in the middle. That’s unlikely due to the expense.
I presume the OP can ask their surveyor to explain and put us out of our misery.

Building control. That is the word I was looking for.

Thanks all. The PWA says chimney breasts will be supported on steel beams.

Interesting point about whether the removal of the chimneys has caused the shift. The window faces out to the garden and on the left wall is where one of the chimney breasts is. I'll ask the surveyor about his opinion.

They have I believe been using jack hammers as they dug up all the ground in the extension area. I'm not an expert though!

Jack hammers can cause vibrations significant enough to affect a building with little in the way of foundations.

Im assuming they aren’t using vibration monitors. You could ask for this as it’s a requirement for buildings regs if they are working close to other buildings and there’s a potential for damage due to vibrations.

@Wonderbug81 have they weakened the foundations????? sounds like they might have!

Oh crikey had no idea about any of this! There's been a lot of rubble (looks like cement) which has been taken away over time. Let me speak to my surveyor and then I'll chat with building control.

Building control will (should…) check whether the chimney breast removal has been done safely ie everything above is properly supported. However they won’t get involved in your window/cracking issues - that is for the surveyors.

It seems pretty clear that their work has caused these issues for you, so under the PWA they should remedy the problem at their cost. I would be quite unimpressed if they try arguing the PWA doesn’t cover it. I hope your surveyor takes a similar view.

For sure and regardless of the PWA it's pretty clear it's caused problems. One way or another it will be fixed and paid for and not by me.

I didn't realise building control needed to check the chimney work, so should they be checking all work done during/end of project?

I ask because my surveyor hasn't mentioned it.

No, they won’t as the chimney is more a making good anyway and not a structural issue for building control.
They will only check what’s required by building regs.
Its worth noting that if the works are not done correctly and they don’t pick up on it they are not liable. So always always keep an eye on what’s being done.

Building control will do nothing more than check structural calculations, the calcs for insulation to conform with uvalues etc. plus depth of foundations. That sort of thing. It’s not for them to ensure builders are building everything as they should as they can’t be on site all the time and that’s the builders responsibility anyway ( as well as the architects if they are taken onboard to run the job on site only ) If BC feel like it they have every right to ask a builder to expose an area that’s complete to ensure it’s as it should be, but they don’t always ( rarely actually ) even do that.