Estimating Extension Cost

[nickd01]

Is there a "guide price" - eg per sq ft I can estimate an extension cost on?

- 12ft * 6 1/2 ft
- Single story, flat roof
- It's basically filling in a side-return in a flat
- Brick construction, ideally we'd like to save the bricks from the existing 12ft wall currently on the side of the flat
- London based

Are there any websites or guides that can give me ball-park numbers to build the shell? i.e no decorating, or installing of kitchen etc

Just need to see if we're even close to being able to afford it!

Thanks

[Busamav]

so first off they have to take down a 12 ' wall , clean the bricks off for possible reuse and grub up the old foundations .

My guess is 20 k.

Edited by Busamav on Monday 12th April 16:22

[B17NNS]

I'd have thought a bit cheaper than that.

£1600m2, about £13k.

[nickd01]

Busamav said:

so first off they have to take down a 12 ' wall , clean the bricks off for possible reuse and grub up the old foundations .

My guess is 20 k.

Edited by Busamav on Monday 12th April 16:22

The old wall does need to come down, saving the bricks was to try and match the rest of the building and to potentially save costs - maybe I'm wrong here.
There's no current foundations; just grass - or am I mis-understanding "gub up the old foundations" ?

[herbialfa]

Just did a quick Google

Found this link!

http://www.growyourhome.com

Never used it or looked at it, but, it might help

[B17NNS]

nickd01 said:

The old wall does need to come down, saving the bricks was to try and match the rest of the building and to potentially save costs - maybe I'm wrong here.
There's no current foundations; just grass - or am I mis-understanding "gub up the old foundations" ?

The foundations for the wall you're taking down - they will presumably be in the way of the new founds.

Swings and roundabouts on the brick side. Good idea to match existing if you can but be aware that any costs saved by not having to buy bricks will be negated by the fact that somebody has to clean up all the old ones.

[nickd01]

herbialfa said:

Just did a quick Google

Found this link!

http://www.growyourhome.com

Never used it or looked at it, but, it might help

Very useful, thanks!
It reckons around £25k.

[dirty boy]

nickd01 said:

- 12ft * 6 1/2 ft
- Single story, flat roof
- It's basically filling in a side-return in a flat
- Brick construction, ideally we'd like to save the bricks from the existing 12ft wall currently on the side of the flat
- London based

To help, mine.

Planning Permission, Submission, Building Inspection and Architect was £1,405

Footings for a 6.6m x 2.7m extension have worked out at £579 for materials (various pipes, trench blocks and common bricks)



Bricklayer can lay at least 500 bricks a day? £120 per day?

Bricks are a £1 each(ish?) 60 bricks per M2? 1500 bricks x 2 for double skin

£3000 on bricks?

7 days work poss?

Cement £3 a bag
Sand £35 a ton

Get measuring and adding up, if you get people in to do the bits seperately, instead of asking one builder to do the lot, you'll be surprised.

[Meeja]

B17NNS said:

nickd01 said:

The old wall does need to come down, saving the bricks was to try and match the rest of the building and to potentially save costs - maybe I'm wrong here.
There's no current foundations; just grass - or am I mis-understanding "gub up the old foundations" ?

The foundations for the wall you're taking down - they will presumably be in the way of the new founds.

Swings and roundabouts on the brick side. Good idea to match existing if you can but be aware that any costs saved by not having to buy bricks will be negated by the fact that somebody has to clean up all the old ones.

Unless you clean them up yourself. (I wouldn't fancy it, as it would be a mind-numbing job)

We re-used our bricks when we built our extension, as even the "closest" match from various merchants wasn't close enough.

The results of re-using were superb.

[Busamav]

B17NNS said:

I'd have thought a bit cheaper than that.

£1600m2, about £13k.

I just haven't seen anything tendered under 15k for some years now ,even the smallest of utility room boxes tagged on , plus if the job is in London it will carry a premium.

Medium sized jobs seem to be around £1650 / m2 then vat when you price it back .

On this job , I am guessing the flat roof lead flashings will be chased in to a cavity wall , that means a cavity tray to be installed in to the existing wall .

Any openings to be formed to get in to the new space ?

Then a handfull of the builders friend " could you just "


edit , better make that 25 - 30k by the time you add some vat

Edited by Busamav on Monday 12th April 21:55