I've had a quote for an extension to the side of my house which was more expensive than I expected. What is the going rate for building work?

The work is remove the existing single skin walled structure, dig proper concrete foundations and build a rendered timber framed building with tiled roof 6m long by 1.2m wide, containing a cloak room at one end and plumbing for washing machine at the other. Plus relaying concrete to the side of the extension.

The quote was £18500 + VAT = £21000 ish.

[Edited on 3-6-2008 by smart51]

typical figures ive heard quoted are 900 per square meter for a bare shell up to maybe 1500 finished.

i know meters spelt wrong, i think metre looks daft

[Edited on 3/6/08 by JoelP]

i've never had an extension built, but when you think about the amount of work and materials going into it, i don't think thats too bad to be honest...
me and my dad have been building a small wall in the garden, not sure on how long it is less than 10m i think, but its cost over £100 in concrete for the foundation already. our foundation's no where near as thick as a house one would be. ours is probably less than half as deep as a house one would be. remember also all the material for the roofing, bricks, plastering, electrics, pluming, floor blah blah blah, then labour...

I'd expect it to be around the £20k mark for something like that - it's more about the time spent on site rather than the size of the extension.

What's the site like for access/skip location etc.

This scares me a bit. I have what sounds like an identical plan to you Smart51, and I was hoping for half that! Bugger. Still, it means I keep my 'workshop' for a while yet!

You can get it done a lot cheaper, but as said, a lot depends on the location and also how easy it is to get in and out of the site - particularly for excavating and moving excavated material, if a builder has to do this by hand and using a wheelbarrow rather than a mini digger and dumper, he'll charge a fortune.

it might be useful to ask what is involved and do some of it yourself. I'm putting up a new house and the builder reckons 70k should do it. 2300sqft. The builder is my fiancees dad and he gets 30% discount at a hardware store for all materials plus being a new build its all VAT free. I'm also a spark and intend on doing all the electrics and probably do all the tracking and boring for the plumbers and also a good bit of the stud work myself to keep prices down. Labour is by far the costliest so if you can do anything yourself it is proabably worth while. I'll save about 60% on electrical costs because i'm doin it myself.

The front of the house has a drive where a skip can be placed by lorry. The side can be accessed with a mini digger.

£21k / 8m2 = £2600 per square metre, which is why I thought it quite a lot.

That sounds spot on to me as im having a 1 bedroom/hall way extension on a bungalow and thats costing me around 18k.

I would say try and do as much of it yourself, hire a bricklayer when you need him but do the labouring for him.

Lay the floor joists and first fix timbering yourself. I did that on my loft extension and was surprised how easy it is and how much I saved.

I did all the wiring myself then just got a registered electrition to overview it and test it. The building inspector was happy with that

I got 3 quotes for the job and they all came in around 45K. That was for 2 extra bedrooms, an extra bathroom and a new pitched roof on the garage. Did as much as I could only getting trades when I needed them and Its cost me 25K. 20K labour saved!!
On this picture i did the lot, joist , insulation, electrical, stud work, boarding out roof beams there. Got the trades in to lay the fancy floor and do the plumbing. Well worth the effort IMO.

Steve

Sounds a quite a lot to me too!

Can I ask a few questions about your procurement process?

Have you drawn up any plans? Or have you paid a designer / architect / mate to do them? If not, perhaps the builder has allowed to do them in house, or he's subbing them out to a mate (and adding his % to there fees).

He might also have included Building Regs fees and Planning fees (depending on whether these would be required). Again if he's included these there will be a % on top.

Have you got a written spec? Trust me it'll save tons of grief later on. He may have quoted on 6" moulded timber skirting, when all you want is 4" MDF with a pencil round top. He may have allowed gold plated taps, when all you want is a budget one!

How many builders priced the work? I'm guessing you've only had the one quote so far. He might be flat out and doesn't need the work, or he might be scared by the timber frame bit. Most builders stick to what they know!

If it was me I'd do the following:

1. Get a set of plans drawn up, don't pay architects fees, get an architectural technician to do it. As existing, as proposed, sections, elevations etc.
2. Get a written spec done, list everything in each room / space. From roofing material to founds. Be as exact as you or your architect can be.
3. Select a few builders, preferably on recommendation, or at least firms who'll let you talk to / visit other clients.
4. Send the plans and spec out to the builders and see what happens.
5. When they send their quotes back in, read every line, in case they have any exclusions, don't just focus on the bottom line.

If you need any more advice, let me know.

HTH

Mike

Do as much as you can/feel confident to do as others have said. Failing that Guiness's post is absolutely spot on and remember DO NOT ASK FOR ANY EXTRAS after the agreed price. It's a licence for them to bend you over and take you roughly.

We had an architect do the drawings and have them submitted for buildings regulations approval, which we have now got.

We invited 3 builders for quotes. One has quoted, a second will send out a quote this week and the third is making a lot of fuss out of nothing so probably doesn't want the work.

The quote that we have is just verbal, on the understanding that he will give us a proper written quote if we think we want to go ahead.

Im not being silly but is there any polish builders near you? I know some people that have just had extensions done by them and they worked better/ faster than the brits and were hell of alot cheaper. Theyr all very pleased with the results.

As said above. Do what you can yourself. Even if u just knock your old one down and dig your footings it will save you alot.

I've just finished mine.

6M long by 3M wide, brick walls and tiled roof with skylight.

Utility room, front room extension and toilet.

I've done everything apart from the brickwork and plastering.

Sub £12k, but I put in a lot of hours and hard graft.

Pat...

And try and get a builder that will take some cash to reduce the VAT bill. You should be able to get one to take at least half cash ...... they at least have to show the VAT on the materials.