What extension does 100k get you?

[TeaOnTheMountain]

I have a detached 3 bed house but I really need a bigger kitchen and a fourth bedroom. Is 100k likely to get me this? I’m in the south west if that helps with pricing. Everyone keeps talking about prices being through the roof - is it worth holding off for a bit?

Good access to all of the house if that helps and I’d do whatever I could to save cash. Management of the project etc.

If it isn’t enough - How much is it likely I would need for a double story with an extra bedroom, bigger bathroom upstairs, bigger kitchen with some big windows?

Any info really appreciated!

Yes if would. But I'm not sure it would cover the cost of the kitchen fit out as well as the construction costs. It would depend on what units and appliances etc you want.

NB when we had an extra room added we also had to upgrade our gas boiler.

I think it would, assuming everything about the project is reasonably straightforward and you're careful in the choices you make about fittings and finishes. We had a single storey extension last year with a kitchen, utility, shower room and store room, and it came to a little more than this, but a two storey extension ought to be a little but cheaper for the same total floor area.

I would think so too, we are in a cheaper part of the country but we recently got a two storey extension with kitchen, and removed a conservatory and replaced it with a similar sized room for about £75k. Some of it will depend on the size and number of steel supporting beams you’ll need and other unseen costs.

It completely depends on so many factors. The kitchen, fittings, flooring, brick, etc that you want. If you keep to a strict budget and don’t go for high end fittings it will be doable.

@GVmama

I would think so too, we are in a cheaper part of the country but we recently got a two storey extension with kitchen, and removed a conservatory and replaced it with a similar sized room for about £75k. Some of it will depend on the size and number of steel supporting beams you’ll need and other unseen costs.

@GVmama - we are thinking of doing something similar. In terms of cost, was converting your conservatory into a proper home considered an extension or just building work (not sure of the correct term), as it was not increasing the footprint?

It depends on the foundations, we were lucky enough to have good foundations so the cost was quite small (£16k to a plastered room if I remember rightly) but the foundations are not always good enough and then you’re looking at a similar cost as an extension. The builder can expose the foundations in a small spot and check if you aren’t sure how good the foundations are. Our house was previously owned by my In-laws and my husband knew that there were foundations for a two storey extension but they still needed to check.
With regards to planning we could do the Conservatory replacement without planning under permitted development as the footprint was already there, but we needed planning permission for the two storey extension at the side of the house.

I think you'd be lucky. We got a single storey extension done, lot of groundwork, bit of underpinning, (£5K), a big steel, 2 sets of big sliding doors. About £90K in all not including kitchen or fitting.

We are in quite an expensive bit of the country though.

I'm not sure project managing would save you any money - with so many trades being super busy you are better off with someone else taking that risk of delayed trades or materials.

I think 100k is about right, but I'd recommend getting a quote from a building company and then assuming it'll be about 50-100% more expensive. So, if you get a quote for 60k or so, you'll probably end up spending about 100k - this has happened to us and seems to happen to everyone I speak to.

We're in the outskirts of London and just about to finish a 100k extension, which included a bedroom (4m x 3.7m) with en-suite and a utility room (3m x 2m). About 20k of our budget was groundworks though, as our back garden is on a slope and they had to remove quite a bit of earth.

Kitchens can range hugely in price - I think the biggest expenses are moving things like gas and water, rather than cabinets etc. Knocking through walls and enlarging windows both add to the cost quite a bit, as you need a structural engineer and likely to need new steel beams.

We’ve just put on a two story side extension and we were 107k.

I don't think it would as it sounds as though not only are you wanting an extension, its also going to mean quite alot of re-jigging of the existing house. We had a double story rear extension about 4 years ago (when prices were considerably cheaper) - we got an extra bedroom upstairs and a large kitchen diner but also meant we had to change the existing bathroom, the landing, access to the kitchen etc, formed an ensuite. When you do that, its not just the cost of flooring for say the "new" bit, you're talking about having to have new flooring for the whole space so it matches. Remember all the extras - your garden will be trashed etc

We do live in an expensive part of the country but it was north of £100k.

Yes definitely achievable.

We have done two £100k extensions on what was a 3 bed 1930s detached house.

First one in 2016 got us 2 new bedrooms upstairs and a study, toilet, utility and dining/family area downstairs (no new kitchens or bathrooms hence we got a lot for our money).

Second one in 2018 got us a rebuilt insulated garage downstairs and a large dressing room (with a lot of fitted wardrobes) and posh ensuite upstairs. Prices had gone up noticeably. Might have been about £90k, lost count.

Now planning our 3rd extension! It's addictive!

We're in SE home counties.

We got quotes in 2020 for a kitchen extension of about 4m x 6.5m and the quotes varied from £70k-£100k ex vat. This did not include sliding doors or a new kitchen. I think the whole thing would have cost £150k all in. We didn't do it as couldn't afford it. This is Greater London.

You might if you're lucky. We looked into getting a single storey 6x3m extension. Architect thought we should be able to get it done for £35k. Cheapest builders quote was £48k and highest was £62k, and that's just for the structure and electrics. We'd still need to fund flooring etc. We're in Wales so assume it would be cheaper than the South of England in general.

Should add ours is current experience. Got the quotes a couple of months ago and have subsequently shelved ideas for a few years.

We’re in the middle of getting a single storey extension which will create a new kitchen/diner and an extra bedroom with en-suite. We’ve gone with a design & build company and the total cost is just under £120k (we’re in the South East).

Great post!

Do you think it would do a Loft and first floor in Greater London?

Building prices seem to have rocketed !!

Good luck with your build @TeaOnTheMountain

@Metalhead

We’re in the middle of getting a single storey extension which will create a new kitchen/diner and an extra bedroom with en-suite. We’ve gone with a design & build company and the total cost is just under £120k (we’re in the South East).

Is the new bedroom/en-suite part of the single storey extension?

noworklifebalance yes, it is, all on ground floor.

Prices have gone up A LOT in the last 2 years. I’d think it’ll get you the build but finishing and kitchen would be on top

Yowsers. I was really hoping it would cover it 😬

Thanks for all the comments everyone, it definitely seems like it will be tight. I probably would need some layout rejigging but reluctant to spend money getting plans drawn up if it’s going to be totally out of budget!

Anything I can do to save costs (other than make it smaller 🤣) ? I’ve read straight rear extensions are cheaper than side etc - does that sound right?

Our 2 extensions described above were one on each side. Our 3rd extension will be right the way across the back and will be around £150k. Imo it comes down to square footage, whether you are fitting kitchen/bathroom and the spec.

This thread is really interesting. We had quotes for a small extension a couple of years ago and they were ridiculous. We have an L shaped living room at the back of our house and we wanted the inside corner of the L knocked out and then rebuilt so it looked like like rectangle. We had three quotes and they ranged from £40k to £60k. Ridiculous amount of money for such a small return in terms of added space.

We are in the South East. We decided not to bother and we're just going to move house instead! Our neighbours on one side went for it and it looks nice. A good bit of disruption for them, and it would have been worse for us as our L was in our only living room so we wouldn't have had anywhere to sit while they were building. The neighbours on the other side looked into it as well and then, like us, decided against it

100k got us a two storey side extension and a wrap around single storey. We basically doubled our downstairs floor area.

That 100k got us to a neat plasterboard finish, all electrics etc, plumbing, underfloor heating, new boiler etc.

Didn't do kitchen, posh flooring, decorating etc, we've done that in bits and pieces.

It will definitely be tight.

I got two quotes just before Xmas and am currently waiting for a third. We have so far been quoted between £135k and £145k for a two storey extension - extending the kitchen and adding a 4th bedroom plus a bathroom.

There are ways to save money if you are able to do some bits yourselves.
We got a quote from one builder to just do the shell of the extension as we are quite able to do a lot of the internal work ourselves if we have to (although if possible I would rather just get someone to do it as I have two very young kids).
We were told £90k .... Just for foundations, breeze blocks, bricks and a roof. So will still need to find a plumber, plaster and electrician, as well as buy fixtures and fittings for bathroom and kitchen.

We are in Kent.

@TeaOnTheMountain unfortunately costs have sky rocketed so unless you have someone in your area saying we had x and it cost y, it will be very difficult for others to help you. Our architect said £150k would cover our extension; we are 13 months in and over £300k. Currently everyone is spoken to having work done is saying " it's taking double the time and twice the price". It really isn't the time to do building work if you can avoid it!