Extending a cellar

[amanensia]

Hi,

We're moving house in a couple of months to a property with a cellar. It's about 12' by 8', is tanked, and is currently unused. The footprint of the house is much larger than the cellar.

I am interested in extending the cellar to, say, twice its current size (say 12' by 16'). The cellar would not be used for living accommodation - it would be a wine cellar.

I guess my questions are:

i) am I right in thinking I would not need planning permission for this?

ii) I don't care if the cellar gets a bit damp - in fact it'd arguably be a good thing, as long as the damp doesn't rise into the house. Is there any reason, in this instance, to require the extended cellar to be tanked, and would it be likely to make much difference to the cost if it wasn't?

iii) is this a "straightforward" building job, that any builder should be capable of completing, or does it require any specialist skills?

iv) the million dollar question - any idea of the approximate cost of work like this? If it makes a difference, access from the top of the cellar stairs to the exterior of the house is very direct.

Many thanks,

Amanensia

 

[Ossy]

Not a straightforward job, and not one to be entered into lightly. Any walls you're going to be breaking through will be retaining at present, and the ground they're retaining is also probably holding the rest of the house up. It's out of my league but initial thoughts would be needing to pile beneath existing loadbearing walls and pinning into them to take the load down to ground beneath the new excavation. Only then could you safely start digging away. Digging out would be a major headache as presumably you don't have access for a mini digger so it would be like the Shawshank Redemption albeit a little less covert.

You'd need some ground investigation done to find what you'll be digging out and find where the water table is, and that won't be cheap. You'll also need a good structural engineer to come up with a scheme once you know what the ground's like. Party wall issues may also come into force depending on how close your neighbours are.

I suspect you're looking at big bucks, and specialist contractors. Might be worth just getting one of those little 'pod' wine cellars that are a couple of metres in diameter and go down about 2 metres, just a hole in the floor. That or a good fridge in a nice new extension that you can also use for other things...