Extending Extension Building Regulations

[Timbo21]

I need some advice please.

I am planning on further extending my rear single story extension within the permitted development criteria,

The idea is to extend the current extension into the garden from 2m from the original house to 3m. However, when my neighbour carried out his rear extension he showed me that my foundations were about 1/2metre deep as oppose to 1 metre. Obviously, the new part will go 1 metre deep, but the original is less. What will building regulations say about this? I presume I have to get them down to inspect? What is the solution?

Thanks in advance

 

[Timbo21]

Bump

Anyone? Please?

 

[noseall]

If the existing extension foundations are on good ground, irrespective of depth, then you will be ok.

Otherwise, it may mean that your new foundations may have to underpin the existing. There is also a risk that should you need to dig along side an existing (shallower) foundation, for any great length, you may risk undermining/destabilising that foundation.

If however you are just abutting it at two narrow points then no worries.

Have you took into account the existing development when calculating your PD allowance?

 

[Timbo21]

Thank you very much for your help.

The idea is to use a timber frame, celotex and render to extend further - length ways only - into the garden, putting it level with my neighbours.

My neighbours extension is right next to it (14cm distance), but his foundations are to the deeper 1m depth.

When you say we might have to use the new foundations to underpin the existing, what would that involve?

Thanks,

Tim

 

[noseall]

When you say we might have to use the new foundations to underpin the existing, what would that involve?

Often Building control are happy for you to dig under the existing foundations say to the centre of the above wall and allow the new concrete to flow under and help support the existing.

 

[Timbo21]

Great, thanks