Price of a room extension? Is this expensive?

[anonymoosy]

Hi...this is the first time I will ever have extended a property. I want to have a medium size dining room added to our house. Room for a 8 seater table and a bit of extra sitting space. Flat roof, off the shelf lantern window for the ceiling. There doesn't seem much point going down the conservatory route as one of the long sides would look onto a wall. Nothing fancy - plain white walls etc...
I'm just wondering if any of you have had a room added to your property and how much it cost. I've been quoted £75/£80k by the architect/engineer and this quite shocked me, so would love if you might share what kind of costs you paid. I'm in the South, outside of London.

If you only want a separate dining room I’d look again at conservatories.

75/80k for one room??????? Way too much

We were quoted between £75 and £85k for a side return extension, so probably smaller than a proper square room. Extortionate. We didn't do it in the end.

That sounds way too much. Broadly speaking you can guesstimate £1-1.5k per square metre. Given that you wouldn't be moving any services and need v little in the way of fixtures and fittings there shouldn't be too much hidden cost. Obviously structural elements like needing a steel can increase the price but we had a new kitchen, rear extension, loft conversion with en suite and total rewire for not much more than that!!

I had a 2x5 metre extension in the side return, with roof light & French doors fully plastered & electrics/decorated & a utility cupboard built for twenty two thousand, the only extras were flooring & radiators which we supplied & they fitted, I’m in south east London borders of Kent.
That was two years ago, so that price does seem extremely expensive.

Twenty two

Forgot to say, we didn’t need any steels, as the opening was only taking out a window & door, so was already supported by a beam.

melen 22k?! We were looking at a side return extension about the same size and the quotes were 45-55k!

True I promise😃

No architect fees, as we knew what we wanted & was in within permitted development, the builder submitted basic drawings to the LA & we paid fees for building regs that was about 550.00 I think.

Oh this is all very interesting....thanks for the replies. I think my jaw hit the table when they gave the estimate. They said this was for a white-wall basic room - no fancy finishes. I've got builders coming in to quote all next week, so will have more of an idea, but the architect/engineer was recommended to me as 'in the know'. I can't believe it, just for a basic room. I have friends who have done spacious loft extensions with bathrooms for less than that!!!!

That seems VERY expensive OP! We had a loft conversion, incl a dressing room with bespoke joinery and a high-end ensuite, had to have the floors lowered on the floor below, fully decorated with Little Greene paints, expensive carpet and full redecoration from the hallway of our house up for £80k- that was 3 years ago in zone 2 of London.

Lofts are much cheaper than ground floor extensions though. It’s laying the foundations and groundwork etc, we want to do a side return and were quoted 80-100k we are London though and that includes new downstairs toilet and a new fitted kitchen.

I means includes fitting, we would still have to pay for tiles, flooring, heating, windows, doors, kitchen & appliances!
It’s crazy!

Are there access issues? Is it a hand dig out or can they get a digger in?

Is your area known to have issues with foundations?

How big is the dining room going to be?

I am in Leeds so it will be cheaper but to give you an idea, I had a 2.5m x 3.3m extension built to first fix (wires in wall no sockets, plastered shell) and I had a vertical steel put into the wall on which the new horizontal steel sat. Cost me £12k all in.

Digger chap was £200 a day, chap who collected the dig out soil was £200 a time (we needed him 4 time as had to level the garden and they can only take around 17-18 ton) and we were a full dig out, no trench foundations, so a full concrete base poured for the foundation.

I did the drawings and the architect copied them and submitted them to planning, under £400. Even the structural engineer was only £160, he didn't even site visit, went off photos of the internal and external wall bricks.

This was 4 years ago. I do know builders price very high if they do not want a job.

Some building materials have gone up 10-30% in the last 2 years. If you can do it in with block work with render rather than bricks that will save you. Foundations are usually more than you'd think (£4-5k) and if they can't get a digger or cement delivery the labour (£130-70 permanent per day) adds up. Insulation is currently expensive because it's in low supply (manufacturing problems). I'm in the SE and the three builders I know say £2k/m2 is a better guide line (including VAT which sometimes isn't added into the calculations). Steels are relatively cheap, it's all the little bits you forget (building regs, skips).

NW here and i think days of £1k-1.5k per sq m are long gone. £2k +VAT is average here and that's without any fancy extras or add-ons.

Seems a little high, but not way off. Have the builders provided you with a breakdown of their quotes so you can identify which (if any) items appear unexectedly expensive? We got multiple quotes for a 6x3 single storey extension (Surrey). The highest quote was over £100k, the cheapest around £55k from a friendly chap who struggled a little with english as his second language. The others were all around £70k. I have absolutely no idea how people find quotes that are in line with the expected build costs per meter.
We didn't go ahead in the end.

I think it's nearer £2k a square metre these days, but yes that quote is super expensive!! Get some other quotes from builders!

Sometimes it can work out nearly as cost-effective to do a larger extension as a smaller one.

how large is the extension? 3x 4.5m? 4x 6m. what type of windows? bifold fully glazed doors? any new garden terrace? could be anything between £30k - £50k.

I wouldn’t expect costs to be less than £2000 per sqm these days, building costs have increased greatly from even last year. Combination of cost increases of building materials, shortages and brexit meaning labour is leaving in droves and remaining contractors can charge a lot more. By all means shop around, but i don’t think you’ll be able to recreate the prices quoted here from 2-3 years ago. You need to work on how many sqm you are adding, a medium dining room could mean anything and is not comparing like with like.

Also, you have to include consultants’ fees (architect and structural engineer) & planning + building regs fees in his estimate (which is what your architect may have done), but that would only be about 15% more on top of construction cost. so if construction cost is say 40k, development cost would be about 46k for example.

We extended last year, part of which was a dining space similar in size to what you are talking about OP. The dining room was part of a new single storey crown roofed extension with 3 veluxs, and also included an extension to the kitchen of around 5 sqm and new fitted kichen. We also built on top of an existing side extension to give an extra bedroom at the same time. I did most of the carpentry myself (my trade. I was heavily pregnant/busy holding a new baby through part of it else I would have done it all) and all the decorating as well as project managing it. DH (also works in construction but at a desk job) did various shit jobs like installing the insulation. We both get good discounts on materials so utilised those, and used tradesmen we knew to get a good price on the bits we couldn't do. It still cost us £55k, but doing our sums we worked out that our discounts and labour got us the bedroom extension and fitted kitchen 'free'. So essentially if we were Mr and Mrs dontworkinconstruction just the finished single storey (no kitchen) would have been £55k if you can understand my sleep-deprived ramblings. We are in Bedfordshire but a stone's throw from Herts.
Your quote seems high, although it's true that materials prices are soaring and if you are in a part of the country with a shortage of tradesmen then they can quote silly prices.

There's a 3 bedroom semi detached house with gardens front and back with off road parking that sold for 65k in my town, not a bad area and nicely turned out..
so about 80 grand for 1 room is bloody expensive in my eyes!!!

I’m in the NE and we had our single storey 3mx4m extension done last summer for £22k as a finished shell. We paid extra for new flooring and a kitchen. That also included building an internal wall and fitting a pocket door to create a playroom and a bit of plumbing work which needed done upstairs as well.