Building costs rule of thumb price?

[V8landy]

Hi

 

Would a rule of thumb be about £1,000 per sq/m for a single story extension?

 

And would that be to a finsied wired typical/avergae condtion?

 

Planning an extension, approx 5 x5

 

In picture below the blue bits are the current house, and the extension is shown. So sort of an in fill L with a bit already there.

[al4x]

depends how its built and footings required and whether you go down the employing each trade and managing it yourself or getting in someone to do it.

 

I built a 2 storey extension on my last house doing a fair bit myself with a general builder that was 32m2 and worked out closer to £750/m2 that was two bedrooms fully finished. I had quotes to do the whole thing that were approx 40K partly due to access issues etc

[Fisherman Mike]

Spot on as long as its not a Rolls Royce spec. or the location dictates abnormal finishes like natural stone and clay or stone roof tiles.

 

Smaller extensions cost proportionally more than larger ones due to ecomomies of scale. You will find that doing it yourself you will not be purchasing as effectively as a builder with a established account at the merchants. Plus Small loads of concrete, cartaway and materials generally will command a small load premium or surcharge.

 

Get a few quotes. All in finished and put provisional sums against items like sanitaryware and fixtures and fittings.

Edited May 19, 2011 by Fisherman Mike

[the_commoner]

as a rule of thumb yes £1000/m2 wont be a million miles out

[V8landy]

Thanks guys.

[jef]

Guide for Estimated Value of Building Work

Based on the RICS Review of Building Prices

 

Effective from 1st June 2010

 

DOMESTIC

 

 

 

 

 

Description of Building Type

Minimum Estimated Value (£/m2)

 

Single storey one off housing (up to 3 units)

1050

 

Multi storey one off housing (up to 3 units)

1000

 

Single Storey estate housing

919

 

Two storey estate housing

729

 

Three storey estate housing

819

 

Housing conversions involving major internal work (Assume structure intact)

399

 

Single storey extension

1050

 

Multi storey extension

729

 

Garages/outbuildings (Generally and un-heated)

362

 

 

 

 

JF

[vampire]

A rule of thumb price of a £1000 per metre has been around for years and is only a guide.

[artschool]

A rule of thumb price of a £1000 per metre has been around for years and is only a guide.

I have found that it varies quite a bit myself recently depending on how keen people are for the work. Round here its about 850m2 including bathroom and kitchen.

[V8landy]

And with this VERY rough (but good guide) of £1,000 pm2, this is to a finished state i.e plastered wired etc,

 

I am looking to do a lot of the donkey work myself, for both cost savings and general interest in the project.

[artschool]

Yes it should be a complete for that money including painting.

[V8landy]

Yes it should be a complete for that money including painting.

 

Thanks very much for that.

[artschool]

Thanks very much for that.

I am sure you already know this but i should point out that you need to have exactly what work is going to be carried out written down in the form of drawing and specification. Saves on arguments over what was expected.

[silpig5]

cant beleive mikee hasnt posted to this thread as its his line of work ,

but

after finding out how he does his work from home from the "comfort" of his office at home ive got that mental image in my head again .

 

forget the naked chef ....try the naked architech !!!

[V8landy]

I am sure you already know this but i should point out that you need to have exactly what work is going to be carried out written down in the form of drawing and specification. Saves on arguments over what was expected.

 

 

Yes, that would be my intention, and the proposed builder is of sufficient standing to draw-up one.

 

Thus allowing me to reduce cost and do some work (withun my capacity and not effect build/er)

 

e.g I will paint or e.g you fit lintel and I will knock wall down below and clear away rubble etc etc.

Edited May 20, 2011 by V8landy

[Paul T]

Been using £1000/m2 for years now and it's still a fairly rough guide to a finished state .

 

I have to ask:

 

The external walls look a bit skinny at about 100mm :blink: so you might lose a bit of floor area if your plan of the existing house is accurate?

 

Also, are you sure you're getting sufficient light into the rooms you're building in front of? Big velux rooflights to throw light into the back of a room will make a dent in your £1000/m2 .

 

Assume you will be putting in a Building Notice before you commence any work?

 

Not being critical - more a 'heads up' as you'd be amazed how many avid DIYers either forget the latter two or think it will be ok to just get on and do it.

[V8landy]

Been using £1000/m2 for years now and it's still a fairly rough guide to a finished state .

 

I have to ask:

 

The external walls look a bit skinny at about 100mm :blink: so you might lose a bit of floor area if your plan of the existing house is accurate?

 

Also, are you sure you're getting sufficient light into the rooms you're building in front of? Big velux rooflights to throw light into the back of a room will make a dent in your £1000/m2 .

 

Assume you will be putting in a Building Notice before you commence any work?

 

Not being critical - more a 'heads up' as you'd be amazed how many avid DIYers either forget the latter two or think it will be ok to just get on and do it.

 

Well spotted!

 

In answer to your questions

 

1 The plan above is simpley B&Q,s rough kitchen plan! We working backwards if you like. Yes the kitchen will reduce a bit, but we know roughly what it will cost.

 

We have only just appointed the architect.

 

2, yes it will make the inner bit darker, but we are working on that in two ways. 1, French doors on the bottom right section which will add a new acces through to the hallway, and bring more light in. and 2, arounf the middle section spanning the new and old will be a flat roof section with a sky lantern in of 2 x 3m size!!! Like this

 

 

3 Architect costs will be fixed price of £600 to get all work done to completion and approval.On top of this we will pay the council directly planning permission £150 and building regulation £361.20.

Edited May 20, 2011 by V8landy

[Paul T]

I must say 'well done' on getting everything buttoned up.

 

£600 for an Architect to design/run your project is a helluva good deal. I used to charge that just for a survey and drawing plans up 10 years ago - self employed not moonlighting!

 

Hope it all goes well for you