Extension estimate costs

[scarvesandsocks]

How much would you expect to pay for the following:
-loft conversion: adding staircase and velux windows only (no dormer needing built)

• converting garage into home office and snug (with raised flooring so no need to dig foundations)
• new kitchen
• new bathroom

I'm trying to get really rough ball park figures in my head before I look for quotes and think about how much I need to borrow.

Also how long do you think the job would take if all done at once?

I'm thinking of asking a firm of architects to manage the whole project for ease and speed- although I know that would be more expensive than doing it all ourselves

£150k

Depends on the spec, but no more than 100k I'd say. The footprint is already there.

Ok thanks- was really hoping you'd say a lot cheaper but as I was typing it out I realised it was all adding up to a lot- especially with a new kitchen and bathroom.

I was trying to keep it so we didn't need major building works or extensions (which is why I didn't want to dig foundations under the garage) I was trying to make the most of what we'd already got.

The next question is how long would it all take- and would we better off moving out (possibly more cost there too)

About twice as much as a builder reckons and three times the architect’s estimate :)

Only really an educated guess based on work we've had done, and of course I'm guessing at sizes and details and it'll vary by location:

loft conversion: adding staircase and velux windows only (no dormer needing built) £40-50K

• converting garage into home office and snug (with raised flooring so no need to dig foundations) £30 - £40K
• new kitchen £15K
• new bathroom £8K

So all in probably £100K + ballpark.

It totally depends on the size of your kitchen/bathroom/loft/garage and the spec
Six years ago I renovated my current house (SE London) for 35k and that included a loft room, moving the bathroom upstairs, new kitchen, two sets double doors put in, plastering , new front door, flooring etc. But I am very good at shopping around and budgeting. I didn't use any architects or have planning costs etc. I used a £100 a day handyman to fit the kitchen.
It can be done very cheaply if you're a tight arse like me 😄

Yeah we're tight arses too and do as much as we can ourselves. We've just gutted the kitchen and replaced everything. Cost 3k all in. Did the bathroom during lockdown including stripping back to brick and replacing the floor and ceiling and moving the waste. Cost 2.5k. We're at a point where electrics are the only thing we can't or won't do.

Ooh thanks all- starting to panic a bit about the money, so I'll take it all quite slowly I think.

It's that toss up of it's worth doing vs saving the money

I've just done a bit of digging around with regards to pricing most of this. I'm in NW England. I have a 4m x1.69 m kitchen, which is costing me £1700 for units, sideboard, sink, decorative cornice, pelmet etc. £1400 for fitting. Flooring and tiles £300 for materials, £330 fitting. I only need 2 new appliances, so whatever I chose to pay there I suppose! All in less than 4k.
I had a loft conversion priced around 25k.
Bathroom I worked out at roughly 4k, obviously depends on what you go for with a suite and tiles. That hasn't been quoted for though, I had to work out costs myself using online tools.
I've asked on here, and looked around online re: garage conversion costs and roughly 10-15k depending on spec, what extras you want eg. En suite would add more.

But it’s all size and finish dependent. Labour is the biggest part of the cost. plumbing, electrics (and might need a rewire if not done in the past 25 years), plastering, decorating, flooring, insulation, taps, lighting, radiators, doors etc

Our house is costing a lot. Hundreds of thousands. But it’s large and a high value property so the kitchen alone was expensive. We are at the same time renovating DHs uncles house whilst he is in temporary residential care after an illness. That is a small 3 bed ex council semi, That is costing under £45k for a full gut, new kitchen, new bathroom, knock through to turn old outside loo into a utility space, block up old front door, new radiators, updated electrics with all new light fittings, replace old gas fire, create new driveway, full skim and decoration and hard flooring and carpets throughout.

I'd be very surprised if you could do it for less than £70-80k unless you can do a lot of the work yourself (plumbing, electrics, tiling etc) but agree you're looking at 6 figures unless you're going really basic for the spec. I think you have to be careful, if you go really cheap it may actually devalue the house. Don't forget it will impact on other areas of the house which you'll need to sort as part of the works.

Materials are very expensive at the moment too so if you could delay I would!

1-2k per square meter. Depending on spec and finish.

Agree much depends on where you are going on the quality spectrum but 100-150k would be correct I think.

Depends on area and square footage but rough estimate…

£50k loft
£30k garage
£20k kitchen (assuming redecorating/flooring is needed)
£15k bathroom again assuming full Reno

Kitchen & bathroom are entirely dependent on standard of finishes etc but I wouldn’t expect much change out of £120-130k

That's all really helpful- thanks everyone.

Yes I'll be looking at starting Jan 2023 so maybe prices might have come down by then (fingers crossed!)

I can't work out why a loft conversion would be more than a garage conversion- is it to do with building stairs do you think?

As really it wouldn't be much, literally just velux windows and a floor.

Whereas for the garage conversion it would need linking to the house, big windows, new roof and floor at the very least.

Ahhh I'm the kind of person who wants it all done perfectly, and truthfully I would likely need new windows in every room too.

The ball park of £100-£150k sounds about right. I'm in pricy outskirts of London. V small house though.

I'll start getting quotes and see how that all works out.

Feels like managing it all would be a full time job though, in terms of shopping around for good deals etc.

Does your loft have sufficient head height without a dorma and where the stairs come it? Allowing for insulation and plaster?
Wouldn't there be other support work needed?
If you are lucky enough to have a loft that requires little other work then it's likely to bring the biggest return but you may also require new fire doors etc

A loft conversion isn't just velux windows and a floor. Lofts aren't built to the same load bearing standards as rooms, so all the joists need to be replaced/strengthened. There's a lot of structural work required before you even get on to insulation and plaster boarding and floors & windows etc.

By garage conversion, I assumed you meant converting an existing, attached garage into living accommodation. If you are also talking about extending to incorporate a detached garage, then that is likely to be £££ more.

I agree, if your garage isn’t actually already attached to the house it will cost way more since you’re effectively extending too. Plus it will need planning permission and it’s likely to be more complex anyway since the floor is unlikely to be insulated and will be sloped etc.

I’m just about to start building work, having spent a lot of time talking with our architect as an independent and knowledgeable voice, his view is that building costs and materials will never come down now - they can charge this much money so will never reverse. So in the end we decided to proceed. It does worry me how much more expensive everything is, but the works we are doing are to ensure we remain in our house for many years to come. I love our home, plot and where we live and want to stay. I wouldn’t be proceeding if we were thinking of moving in the next couple of years.