Extensions: single storey Vs double story

[Consigliere]

Chatting with several friends (who have had extensions in the past) and discussing my plans for a single storey rear extension. I Should be able to get a 6m x 7m single storey done under PD. I can of course have a double storey like a neighbour has done and add an additional bedroom - which we could do with but I suspect would be a considerable amount more.

All of my friends said adding a second story wont double the cost and would not be much more, which has now caused me to rethink my plans.

Question is how do I get costs for a single storey vs a double storey without plans? I don't really want to pay an architect twice to draw up plans for single storey and double storey so that I can get quotes - what's the best way to proceed?

[Consigliere]

z4RRSchris said:

single floor extensions in SE are coming in at £2500-3000 psm at the moment, which is a piss take number but thats what it is.

add a floor and add 70% of the above rate on the area.

good estimation.

doing it under PD (the larger extension neighbour consultation scheme to get 6m) prefereble than inviting all your nimbys to have a view.

I'm in the West Midlands - i think the going rate here is between £1,500 to £2,000 per sqm.

Equus said:

This is only applicable to single storey extensions (and it allows up to 8m. if your property is detached - the 6m. figure applies to non-detached).

Personally, I'd suggest that if you're planning to spend a £6-figure sum on an extension, it's short-sighted to compromise for the sake of a £few hundred and a couple of months wait.

Your immediate neighbours get to comment on the 'larger extension' PD scheme, anyway, but in any case neighbour comments don't make a huge amount of difference either way - the Planner will make their own decision, largely regardless of whether the proposal is supported or opposed by your neighbours.

Yes, mine is a semi-detached so I can go out 6m, property is 8m wide but i need to allocate some space for side passage and i don't want to build on the boundary with my neighbour. Also 6-figure sum is not what i think it would cost, but do need a ball park.

i might have to call round a builder or two for tea and cakes whilst they give me an opinion on what they think - if its 6 figures for a single storey its a no -go from me, just cant finance it.