Ballpark for two storey extension and full refurb

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Any ideas how much a two storey extension, remodel and full refurb (kitch, bathrooms, paint and carpets) would cost? I know it’s how long is a piece of string! I would project manage. We would need an architect and builders. We could do some diy ourselves though probably not that much. Not high end spec but not ikea either.

And does it cost significantly more for a two storey? If it was just ground floor and remodel would that cost a lot less?

Impossible to even give any idea at all. With that detail it really is how long is a piece of string

Area of the country
Size of extension
Size of existing house
But no matter where you are i would imagine 100k+

2.3-2.7k per new sqm. Refurb is wholly dependant on what you want done. Single storey is obviously cheaper than 2 but the 2nd floor isn't really that much more expensive (that's relatively) as in a single storey you still need a very expensive roof so you might as well put that roof on 2 stories as 1.
With more floor space comes further cost to fit it out

£150k - £200k approx South East.

Agree that its impossible to say. Our double storey extension worked out at about £2k per sqm plus VAT but that was to a plastered finish (including glazing, plumbing, electrics). Everything else (kitchen/bathrooms (and fitting), flooring, upgrades eg for radiators / doors +door furniture / bifolds, garden, drive, decorating etc) was on top of that and the rest of the house was in fairly good order.

I also think building work prices have gone up since we had the work done.

We are looking at single storey exension (not huge - a steel, 2 rooflights, cornered glazing with sliding doors) , 2 bathrooms, new radiators, water cylinder, new kitchen, some new windows, complete redecorating with some plastering required, refurbishing wooden floors, new front door, putting in a back door, new patio.

It's knocking on £180K with a contingency that we think will be spent on drains. 100 year old house.

Build, electrics, plumbing, glazing, decorating but not inc kitchen, flooring, bathroom, tiles or the fancy windows we're having in the kitchen is coming in at £110k+VAT for a two storey extension (90sqm).

All of the above plus refurb of the existing house (100sqm) and now inc the flooring, bathrooms, kitchen etc is coming in at about £210k+VAT but realistically I think it'll be a bit more once we've chosen final finish.

In the south east.

We did this 10 years ago including all new electric, heating, windows, kitchen, bathrooms x 3, two story extension. Roughly £140k

We've literally did this last year £200k SE. Do not project manage it yourself unless you have nothing else to do and some experience of dealing with building regs etc. get a good main contractor, will save you a fortune in avoiding mistakes etc. It will be completed much faster too.

Should say that price is ex VAT.

As above, I wouldn't project manage it myself - unless I really knew what I was doing - its an expensive way to learn. There's so many inter-dependencies and trades to manage and get right. it'll be quicker and cheaper in the long run to get someone to do that. There'll be enough questions to answer without that.

This is extremely useful info.

The second floor doesn't cost as much as the ground floor as the ground floor alone would still need foundations/drainage/roof etc.

We've just added a two storey extension, 80 sqm, and it was £120k in the SE.

That includes new boiler, new windows in existing house, electrics, plumbing, plastering. No flooring/carpets, no kitchen, no bathrooms.

When you say ‘project manage yourself’, what do you mean exactly?

• we have a main contractor and I go to site every week and talk about what’s coming up, what’s happening, issues etc. We have chosen kitchen/ sanitary ware/ tiles and I coordinate deliveries on some of these.

• I have not employed a ground work company, ordered concrete, drains, suspended floors etc (etc, etc), which is the project management of a main build.

The first element is time consuming, the second, you need to know how to read plans and how to build.... or be prepared to learn.

Ah thanks everyone amazingly useful. I was reckoning about £200k. SE. London really. Unfortunately I think we’re not going to go for this one. It has not put me off a project though. We’re not for it as road near it too busy. By proj manage tbh I don’t really know what I meant but basically the first one @positivelynegative not the second. I have no experience at all of a renovation. The real issue I’m seeing is how we live during it all. Portacabin? In one room. I have two kids eek. And reckoning it must take about a year really to do!?

Well having lived in 2 rooms with a baby, and then moved out to a rental on another project, I can tell you which is easier. The rent is killing us though. Neither is cheap, but a caravan on site needs a lot of space too. We looked at that and couldn’t make it work with all the building kit.

What you’re describing is having a builder OP, not project managing it. It’s the right choice, being the client is hard enough.

Good luck with your search.