Ballpark figure for this extension plan

[NameChangeEveryDay]

Thinking of buying an ex-council house on a large plot in our dream location. Is anyone able to give a very ballpark figure for this extension plan? The extension is in the red area. It would pretty much double the footprint, new bit measuring 13ft by 22ft.

Would also want to:

Knock through the current living room and kitchen and make it into a new kitchen/diner

Make bedroom 3 into a bathroom

Make current bathroom into a utility room

Wondering if we are being at all realistic

[Howareya]

Not an expert but having had similar plans, we had to scale back. Essentially you are taking out the side (or back) of house and will need to put steel in place to hold up new structure and this could be pretty expensive.

Al depends on what the soil is like, if there are trees close by, how accessible the site is to builders, ie would they have to dig out foundations by hand or get diggers in easily.

Also depends what part of country you are in.

Do you know any builders who can have a look at floor plan. I imagine they might be non committed without structural engineer drawings. Sorry, I know that doesn’t really help in terms of costs. I would add, don’t necessarily trust an architect to give you an idea of accurate costs. A quantity surveyor would be better placed to do this.

[toooldtocare]

I did something not dissimilar about 5 years ago in SE and it cost us 80k. But it is so variable we had issues with foundations and I am not convinced I got the best deal but I liked the builder and we worked well together. We did nothing and the builder project managed the whole thing

[titchy]

You could always start with a single story, with 2m foundations, if it's too expensive. But agree you should prob budget £50-£100k.

That said - can I suggest if you go ahead that you get a decent architect. Those plans look quite poor to me - you've not gained any extra rooms and the layout is still bad.

[birdbrained]

Honestly we are doing something not so dissimilar but maybe more structural work - e.g knocking through. With new kitchen, 2.5 bathrooms, whole house rewired, re-plastered, almost all new windows, landscaping. About 170k including VAT... was horrifying. Can build a new house for that!

[nomdeguerrrr]

The extension there is around 53m2. Rule of thumb now seems to be 2k + Vat per m2. Given its double storey you might be able to get it down to 1.5k per m2 but you'll struggle to get lower I think. So maybe somewhere between 95k and 130k for the extension.

Then more on top for the remodeling of the existing.

[Yubaba]

We are having a 2 storey extension built at the moment, it’s 70m2 and it’s costing us £100k to 1st fix. We need a kitchen and bathroom on top of this.

[NameChangeEveryDay]

Thank you all. That's quite a bit more than I was thinking!