Demolishing Garage for Extension If you want to know how your DIY projects could be affected by building and planning regulations, click here to post questions and view answers

[Billy B]

I am currently planning a two-storey extension to my property.

To accommodate the extension I will have to demolish my garage.
However, my garage is basically semi-detached with my neighbours. i.e. there is a party wall seperating them.
My neighbour and I suspect that the garage party wall has been built up on the concrete floor of the garage.

Is there anyway to check/confirm this prior to demolition?

If our suspicions are correct, and I want to remove the concrete floor on my side of the party wall, are there any regulations I should adhere to or can I remove the concrete floor right up to the party wall?

Also, under what circumstances could I be legally bound to provide any reinforcement to the remaining concrete floor and party wall?

Any advice and help anyone can give would be much appreciated.

Regards
BB

[welsh brickie]

The building inspector will insist you dig an inspection hole in the garage floor to check the foundation to see if its adequate to take the additional weight of a further floor.Based on his assesment he will decide if the wall needs total removal

[Billy B]

Thanks for the reply Welsh brickie.

However, I think I should have explained a bit better.

My garage is detached from my house, there is a path to the rear garden between them.

The plan for the extension is to demolish the garage and effectively move it towards the house. Thus, creating an integral garage on the ground floor of the extension and an en-suite bedroom on the upper floor. New foundations will be dug for the extension.

The pathway to the rear garden will move to between the new extension and the current Party Wall of the garages.

The party wall between the garages is of single brick construction and we suspect that it has been built up from the floor of the garage and may not have a foundation of its own.

I was hoping to remove the concrete between the new extension and the party walll and replace it with a block paved path to the rear of the property.

My neighbour is concerned that by removing the concrete on my side of the party wall it will weaken the wall, and is almost insisting that additional support is provided. My neighbour also wants to know what I plan to do about it before work commences or they will raise a dispute under the Party Wall Etc act.
Hence the questions in my first post. The only thing the wall supports is the corrugated roof of the garage itself.

Any advice on how I solve the problem?

Many thanks
BB

[welsh brickie]

Before you start work of that magnitude,you will need to submit a set of plans to the council.so your first step is to contact an architect he will draw up what is required,You can then consult with your neighbour what you plan to do.Remember he can object so keep him in the picture.
With the plans you can also get an exact price from your builder.

[Billy B]

Already have plans drawn up and have planning permission from local council. Next stage is Building Control.

I have also been keeping my neighbour informed throughout the whole process. I thought all was OK with the neighbour as they have never said anything directly to me about their concerns. However, I have recently received a letter (which has also been copied to the local building inspector) raising various points about the party wall and the garage roof. My neighbour is insisting on answers to these points or they intend to raise a dispute under the Party Wall etc Act.

As I see it, I am doing nothing to the party wall other than removing part of the load as I will be removing the roof off my garage. The party wall is not being used as part of the extension. One side of the wall will change from internal to external and I am planning to have that side re-pointed.

The only thing that concerns me is the thickness of the concrete floor of the garage as we suspect that the party wall has been built up from this. Is there a minimum thickness this concrete should be?
If the concrete floor is not of a certain thickness will it require re-inforcing?
If so what form does the re-inforcing have to be?

Many thanks for the help.

Regards
BB

[welsh brickie]

I cant really answer that question about whether the floor is able to support the weight,Thats the building control officers job,What you can do is hire a diamond core bit and drill from your local hire shop, and cut out a hole in the concrete to see the thickness for youself.the BI will probably want to see this anyway.