Side return extension cost - London (plan included)

[Sandrine1982]

Hello.

Can anyone please advise and give me a ballpark figure?

We're thinking of putting an offer on this house but it has a tiny kitchen and the bathroom needs to be moved upstairs.

Has anyone had anything similar done recently?

Can you please give me a rough figure for these two options:

A) Extending the kitchen but without side return (by just moving the bathroom upstairs and extending the kitchen)

B) Extending the kitchen with side return, pitched glass roof, plus moving the bathroom upstairs

Thanks so much

Side return: 2.5k per m2 for the whole affected area (ie not just the new building but also the existing rooms that will need reconfiguring. In your case the kitchen and bathroom). So 25k (though that sounds a bit low tbh. You’re considering a very small area and economy of scale would mean that a smaller area would work out slightly more per m2 than a big area)

Also there might be other unknown issues. Eg if you needed to move a drain that would add to the cost.

Difficult to know how much moving the bathroom would be. Depends where you’re moving it to and how the pipe work and drains line up.

Wow that sounds very low re above post & for London. Of the 5 people I know in London done side-returns recently (small Victorian terraces). The cheapest has been £85k. Highest £147k. This is build only not including kitchen/flooring etc.

Extension without side return should be much cheaper as you won’t need the steels & as much new foundations. Maybe £40k?

We’ve had a few quotes for similar in London. I think you’re looking at £60k for the build, plus however mich you want to spend on the new kitchen and decorating. Our view was you don’t get much change from £100k.

What @LeavesOffTheCactus is quoting is for shell only. It doesn't include the new kitchen or flooring or added electrics and decorating. £60k more like it.

It wouldn’t be worth doing option a
You’d still be left with a really tiny kitchen

Option b - £60-100k all in, depending on how complex the site is, the standard of finish you want

Also factor in needing to live somewhere near else for the duration of the build because you won’t have a kitchen or bathroom for 3+ months (unless you move the bathroom first and then tackle the downstairs) plus if it’s mid terrace, it will be very hard to live with the builders traipsing in and out

I know its always more expensive to get it in London - usually helps though if you can compare quotes, that's what I've always done :) somewhere like conservatoryonlineprices.co.uk does that for extensions and so on

Sorry but I’d say £150k all in for the side return and moving bathroom. Prices have gone up a lot since covid/brexit.

Best bet is ringing up a local builder (look on Nextdoor for recommendations) and asking them for a very rough ballpark for this sort of job.

Option B.

I have had several quotes for a side return, and you do not have economies of scale because of the relatively small size of yours. You should budget for £55k I would say, to do this to first fix. Mine is 6 metres long and 1.5 wide and my quote is £75k.

We are in London and are starting a big building project next week that includes a side return extension. I’d say 100k alone for just the side return with a mid spec kitchen. So including contingency option B would probably need a budget of around 150k.