Building costs for knocking out load bearing wall, installing steel supports and some other structural work

[cedle]

Wow. I admit it was done 8 years ago, but we had a two-storey 3m x 10m extension with pitched roof built from the ground up inc. all electrics and plumbing & plastering for £33K. Were in the East Midlands.

Just asked a builder for a quote. Roughly:

• Remove load bearing wall and install steel (length 3.5m) (calcs have been done by structual engineer)
• Remove 2 x 2m flat roof (half wood, half concrete) and put in new wood one.
• Install 2m steel to support floor above flat roof
• Remove two existing windows, enlarge aperture and supply & fit

new basic white pvc 1800 x 1000 and 1400 x 1000 windows

• Brick up old back door, render outside to match finish
• Create new door opening in brick wall and install basic white pvc door 840 x 2085
• Move mains water supply a few metres back to outside wall and re-route up and along new steel to bathroom upstairs
• generic electrics for new kitchen
• generic drains & water supply for new kitchen (details to be firmed up on kitchen design)
• Plaster walls

And that's about it. Taking off the optional parts of the quote and the kitchen fitting costs, I've been quoted £20K for this! I'm flabbergasted and can only hope that this, as the first quote, is the "expensive one" we all laugh at when the other quotes come in!

I was expecting at least half that cost, even with door and windows cost in there (which will be £800 or so, based on trade website I bought previous ones from). Maybe I'm miles out and will be further disappointed if this quote turns out to be the cheap one!

That’s about right. That’s also quite a lot of bitty work that could go wrong. Also you have demolition of something concrete. You have skip costs presumably. I think you are a bit out of touch if you think you will get it much cheaper!

Also, £33,000 was dirt cheap. You are now looking at £1500 per m2 (at least!) for an extension so your 30m2 would be £45,000. That puts the £20,000 into perspective. Ask the same builder if they are still in business.

Sounds reasonable to me. How long do they estimate it would take?

@BubblesBuddy - at the time we got the extension done we were told £1K per m2. Bear in mind it was 2 storey, not one, so 3 x 10 x 2 = 60m2, therefore we got it done at "half price". The builder is still going strong and has a waiting least of over a year, so he must be doing something right.

I think it's way overpriced for the East Midlands. I suppose time will tell when the other quotes come in.

waiting list, not least!

@MummyShark2018 - approx 2 weeks apparently. Maybe a couple of days into a 3rd.

Well £1000 per m2 is out of date now. If he’s cheap, that’s probably why he has a waiting list.

@BubblesBuddy

Thought you'd be interested to know that I got three further quotes in and all were within a grand or so of each other at... £12K. All with good references (2 from friends who have used them) so maybe you need to readjust your pricing expectations.

My pricing was the current standard used for calculating extension costs for bog standard extensions. Great if you’ve got it for less but it depends what is included and what your extra costs will be. You didn’t get it for at least half the first quote though!

20k is way too much.