Cost of an extension

[Thatsajokeright]

Hello!

Can anyone give me a ball park figure for what building work is costing at the moment, please?

We're looking to put a 5ft extension on our property which will make the kitchen/diner wider but we'll also be able to section off part of the kitchen to create a utility room.

We're in the South West Bath & Bristol, if that helps.

Materials
Size
Internal works required?

need more info

Same area. We have just completed a big project. £2.5k pm2 including vat kitchen etc. relatively high end.

Smaller projects are generally more expensive per m.

My builder is worried it is all about to fall off a cliff.

Convert the garage to a room
Add 5ft extention on the back to extend what's already there (24ftish long) but put an additional wall up to create the utility room.

Materials - I've no idea! Whatever the usual ones are for small extensions, I guess?

OP no actual practical advice but from several friends who are trying to get building work done right now the rule seems to be whatever you think it's going to cost then multiply it by at least three. Prices have gone absolutely insane.

We did something of a fairly similar size in the Cardiff area for about £100k a couple of years ago.

Obviously the total will depend on what flooring, kitchen etc. you want, as well as on access and site conditions. Even with that in mind, our experience isn't very relevant any more: a friend who is currently getting quotes for similar work reckoned it would cost twice as much now.

Sorry OP, materials I meant are you wanting a brick match or render or timber for your new external walls.

The trade is still absolutely booming and I don’t know a single one who is currently worried. Every employee, subby & contractor we use is booked well into the back end of next year and all these cancellations people talk of are not the case for any of us.

I saw something today saying to budget £3.5k per square metre, with VAT on top of that, to a plaster finish for building something from scratch. We’ve just built a single storey extension and the build part plus turning a galley kitchen into a downstairs loo and utility works out at about £3.1k per square metre before VAT.

Can’t help on the garage conversion cost though…

We just got a quote from the build we used for our extension before for 4.4k per square meter excluding VAT. This is a kitchen extension of about 13 sq meters. This is the complete job including fitting kitchen. It is just under £70k 😨

The £70k is including VAT because I have to pay it.

@NCFT0922 we used a large main contractor and project manager. They are in the more premium end of the market and are definitely worried for the medium term. We certainly didn't need to wait for any trades to turn up once the project was underway. Everything will slow down without cheap mortgage borrowing as very few people have a spare £200k in their bank account.

We have added 150m2 so will have had economies but are also higher end (handbuilt in frame kitchen, vaulted ceilings, 4 full bathrooms, ufh etc). To be honest at 3,500 plus vat for only an unfitted plaster finish would have been totally unaffordable as fitting out is at least anoth £1k on top. We paid about £1300 plus vat to get to that stage with fitting out on top.

Cripes. Some of these quotes are enormous!

I was hoping for about 3k per m2.

Does it make a difference if we just built out over the garage instead? As opposed to going out into the garden. Less to do in terms of footings. Assuming the current ones are adequate!

@Thatsajokeright the builder quoted was the one that built above the garage for us. I don't know how it compares to a ground floor build. But we need foundation reinforced because the garage is single skinned. This is a integrated garage from the original house build too. We added just over 30 sq meter, a new ensuite and that came in around £100k. It's just over £90k to the builder. He project manages so that includes all the plumbing and electrical costs.

I just did the maths and it's £3300 per sq m. So I think your £3k per m2 is realistic.

3.5k per metre squared for the whole affected area. So although the extension is just 1.5x8 the affected space is 6x8. Total cost £165k. That includes all fixtures and fittings and a 20% contingency. London.

We've been quoted around 35k-40k for a very similar thing to your drawings, garage conversion and extension at the back of it around 3mx4m. For just the shell (no electric, plumbing, just walls and roof really) it's around 23k. We're doing that and doing the internals ourself to save some money.
Going up above your garage will likely be expensive too as might need new foundations whereas conversion won't. I'd recommend getting lots of quotes as they varied massively with ours and we went with the cheapest.

£3k/m2 for a shell maybe. On top add flooring, painting, electrics, plumbing if needed. So £75k sounds about right, though I'm sure you could get it cheaper if you do a lot of shopping around and negotiating.

We want to do a 6m x 3m single storey rear extension. Our first quote has come in at £75k including VAT but with no kitchen, final floor/wall covering (and reusing bi-folds). That’s roughly £4.1k per sq m. Ouch! We’re in the North-West.

At these prices will it be cheaper to move?

The plasterer we use is always very busy, but when he was doing a room for us a month or so ago he was concerned about how things might go in terms of work slowing down in the future (he has three employees). I think he'll be fine, as he is very good, and at the expensive end where people get him because they want the best job. I suspect the ones who will get slack are those who aren't so good and/or don't have people fighting to book them now, because they are just starting up, or whatever.
Generally, I think round here (NW England) the trades are still very busy. A friend with a doer-upper strggles even to get quotes, and when she accepts a quote and says she wants to go ahead, all she gets is silence. But if interest rates are going to be high, there will be less money about for things like extensions, and the covid-driven extension boom will cool at some point.