Per SQM Kitchen Extension Cost

cjayd

Hi
We are considering a kitchen extension to our Victorian terrace house.
Currently the kitchen is 17SQM in floor size.

The land area to the 'side of the kitchen is 18sqm.

The extension would be a typical pitched roof, with 3 Velux skylights in it.
And then a 3 metre trifold/quad fold door at the back of the extension
The 6metre long length of the kitchen would be entirely knocked out, with a large RSJ placed to support the upper part of the terrace house

My question is:
I see a lot of referrals to industry standards of £1000 per SQM or £1500 per SQM (we are in East Berkshire, UK)

But does this refer to:
** the size of the new extension (18sqm)
** or the total floor area (17+18sqm)

ie I cannot see how it can refer to just the 'extension' element, as plumbing, flooring, plastering, wiring, floor concrete etc work will take place throughout the entire existing kitchen area and the new area - in essence knocked though to create on entirely new and large room.

Would appreciate any comments

diable

It will also depend on the foundations as they may need to go deeper due to the soil in the area.

I know it doesn't answer your question but there are varying factors to be considered.

Hintza

£1500-£????/m2. Assuming you don't go mad +/-£300/m2 upwards will be the cost of the kitchen.

teneighty

The square metre rate method is only intended to be a very rough guide to give you a budget estimate and should be based on the gross floor area of the extension only.

From your brief description with the rooflights, sliding/folding doors, RSJ etc. and suggestions of additional work to the rest of the house and your location I would say up around £1500/sqm maybe even slightly higher. Obviously if you are having a handbuilt bespoke kitchen you would need to increase the rate even further or price the units as a separate item. But like I said that is only meant to be a rough guide giving a budget of £27,000 plus VAT and any professional fees. If the works to the existing kitchen are major (I don't know why you would need to dig the floor up?) add an additional allowance for those works, say £5000 as a guess.

If you want a more detailed estimate you'll have to price all the individual elements of the build and work up a price that way. That is how the contractor or his estimator/QS will do it.

cjayd

Our quotes so far have been 36K ex VAT (or around)
Thats purely for: the building work (brick ,plaster, ground work, RSJ's, Plastering to finish, 12 lights, 12 sockets, electrics, basic trifold door, 3 velux's (basic)

i.e. Foor tiling, Labour for Tiling, Final Painting etc etc are all extra.
Kitchen and Kitchen Fitting are all extra.

If I take this on the 18 SQM of the extension, that would be 2K per SQM, and this is just a common garden variety 'side kitchen infill extension'
Which seems to be a touch on the high side.

The reason I asked about the existing internal space (ie the 17sqm), is this 'per SQM very rough rule of thumb' on various forums always refers to the SQM of the actual extension.

ie If someone had an existing kitchen of say 20SQM, and then an infill extension of 10 SQM, but the infill mean the entire 20+10SQM is being refurbished, these 'per SQM' rules can be very misleading.
eg if you are laying new concrete flooring throughout the 20+10SQM there s a cost.

Hence the reason for asking for some guidance on the existing 17SQM + the 18SQM.

But I agree - The builder that had had the best quote so far, wont break out their quote - even though they talk about using a professional Quantity Surveyor etc etc

teneighty

If you have had a number of quotes already then that is the best guide of the costs you will get. We haven't seen the site or the drawings and do not know the local market so can only give a best guess.

My gut reaction is the quotes are a bit high but the local contractors may be busy so can afford to push their rates up....who knows?

I would be concerned if the contractor is refusing to give a breakdown. I know they sometimes worry that their rates will be passed on to competitors but I would have thought they could have given some idea so that you could look at areas to save money. Try discussing it with your preferred contractor, they probably understand the job better than anyone else.

The square metre rate is not used for refurbishment work because the work is too variable, no two jobs are the same. You can have a square metre rate for plastering, flooring, painting but I've never seen overall rates quoted for refurbishment generally. Like I said before, square metre rate for the new build and a separate allowance added on for the refurb would be the norm.

cjayd

TenEighty
Thanks (and thanks to the other commenters)

I pretty much agree with everything you've said.

We have had some 'good' first verbal quotes - unusual as 2 of the builders have already done exactly the same extensions in our area (ie all terrace houses in our area are 'identical' in Square Footage etc.), with exactly the same velux's etc etc -
ie Its a bread and butter extension

But as you say - if demand is high, they might be attempting to up the price.

ie in the current environment,, less people are moving and the rate of renovation in the area has increased over the last 18 mths.

roses

Hi, I have got three quotes so for , for my side infill victorian house. Current kitchen is 7m x 3m and the total size when finished will be 8m x 5m.

Quote 1: Approx £35k + vat
Quote 2: £40k inc vat
Quote 3: £70k + vat

All of the above is plus the cost of tiles & kitchen units but includes fitting costs. I think your quote for £35k is quite reasonable.

What part of the country are you in? I have found prices don't really vary much these days based on the region, even in London but if you are in the same area as me then I can give you the details of the company who I've chosen to go with (quote 2) as they came across as the most honest, provided references, a detailed quote etc.