Extension costs?

[Watto1]

I realise that the answer to this is probably "how long is a piece of string?" but here goes!

I'm considering a single storey extension to the side of my house. It's to make the kitten bigger, add a downstairs loo and maybe a small study (if there's room). Size-wise it'll be roughly 8m x 2.5m.

Any idea of how much this will cost? I have absolutely no clue whether I'm looking at 10k, 50k or 100k!

Thanks in advance.

Obviously, that should be make the kitchen bigger, not the kitten. My cat is already an adequate size!

We're starting our extension on Sunday. We're costing in about £50k including kitchen. Dh has contacts in all the different trades ie; our next door neighbour is a plasterer, dhs bf is an electrician. I'll be pleased if it's less, but we'll see.

We're knocking our downstairs toilet out to make the kitchen bigger, but then having it moved to the front of the extension, a laundry room, 2x storage cupboards, and of course the playroom/office. We're also boxing in part of the kitchen for a pantry.

My dh got loads of quotes from different builders. Some were based in London as we're north of London, and those quotes were ridiculous.

We did this to our small property in SW London.

We added a 4x3m extension, which included a new bathroom & french doors at the end of it. Our builder charged us 30k.

We left the kitchen in the same place, but added a few new cupboards and redid the worktops.

We also moved around the stairs which was a big job! I think about 10k of this went on stairs and upstairs changes which were not really part of the extension.

We then spent around 6/7k on tiles for the floors, the bathroom suite and the new bits for the kitchen.

I'd say 50k sounds about right if you are keeping most of the kitchen in the same place.

We kept costs low by buying everything online - tiles, bathroom suite, paint etc. We also got the builder to break down costs in his quote so we could see what the big expenses were and consider if we really wanted them or if we could work around them somehow.

Don't forget that costs vary hugely by location, so take that into account :-) We are London based.

Thanks for the reply. That's a bit more expensive than I had hoped but I really have no clue. We're in Wales so hopefully it may be a bit cheaper here. Good luck with your extension.

Aren't you supposed to

Sorry, I meant aren't you supposed to estimate it at 1-1.5k per square metre?

So a minimum of 20k for your build, plus kitchen & flooring costs (and fitting them).

We've just had ours done and it came to about £1.1 k per square metre I think in the end. That included 2 lots of bifold doors. We're in the north west. SE prices are silly if you ask me. In Wales it will be much cheaper.

Sorry, x-posted with you the girlwhouk. The stairs will be firmly staying where they are! We've got a bog standard 3 bedroom semi. The extension will be a simple rectangle added onto the other side of the stairs. The house next door has done what we want but it wasn't the current owners.

Thanks Curlyhaired Assassin. That sounds a bit better!

For build work around £1500 psqm is the norm, your kitchen can then add 10's of thousands on it or a few thousand it all depends on what you are putting in.

We did a single storey kitchen extension last year which worked out at £1600psqm, then the kitchen itself cost £9k all in.

The build work should take you to plastered shell and first fix electrics and plumbing ie the pipes and wires are done waiting for second fix - plumbing in a sink etc.

We are in the second week of our build.

Ours is 2m x 5m. We are knocking through to make a kitchen diner and extending the rear of the property. The shell, windows (one kitchen, two velux), patio doors, plastering, moving drains to side of house, roofing, beams etc with labour is around 17k. New kitchen is 10k.

We are in surrey.

The 'piece of string' comment is about right!

The rough guide of 1,500psm is probably fair outside London however so much of a kitchen is variable - one could spend 5,000 or 15,000 on kitchen units alone. I assume by your dimensions it is to be a flat-roofed 'box' across the back of your house?

In the last 2 years I have designed 8 of these, all approximately similar areas to yours and all bar one attached to modern(ish) 'estate' type houses. Costs varied from 18,000 to 43,000.

Cornwall prices, local and well regarded small building contractors who supplied all materials and employed sub-contractors.

The 'other' one was to a 16 century cottage and was completed for a very reasonable 72,000!

Good luck with the larger kitten as well

We've been looking at extension costs recently as we've just put in planning permission for a 2 storey extension. Based on our research (we're Wiltshire, so not extortionate London like other posters), I would say allow £20k to £30k for the build of your extension (based on a 20 sq/m total area, multiplied up by £1k to £1.5k per square metre seeing as you're Wales & hopefully won't fall into the £2k per sq/m pricing!)

PLUS kitchen on top of that would be another £10k-£15k.

So total cost anywhere between £30k - £45k

HTH!

Sorry, only just seen the last couple of replies. Thank you for responding. I certainly hope it won't be 2k per square metre! Got 35k max to spend so I might be OK. Next step is to get quotes I think. I'm getting excited now!

You can do it, Watto! I used to read all these sorts of posts and really really want to do it, but be put off by all the hassle of the various different stages. Seemed so scary and "grown-up". And now our build is finished and the kitchen is going in and I love, love, love how it's going to all look when the final interior decoration/design is done. I feel like I've got a new house with only a tiny percentage of the hassle, stress and costs of moving!!!

Hi.

Sorry to drag out this convo from the past.... It's just we're looking at a rear extension similar to your size and I was wondering if you would recommend it seeing as you've had yours done. Our size is 2m x 5.7m so similar to yours.... We're going to use it as a play room? Would you recommend it? Is the size big enough? We've been quoted 12k and I'm just wondering if it's worth it due to the 2m projection not being very much. If you could reply that would be so helpful. Thanks in advance