One bedroom + box room extension

[razorback]

No plans yet and no planning permission as yet. We live in a semi detached 3 bedroom house. We are looking to extend hopefully creating 1 bedroom + 1 box room/office.
We are looking to retain the driveway leading to the garage so essentially having a 1st storey extension over the driveway.
A few questions:-
Do builders prefer to do the whole job as opposed to client supplying materials and asking only to complete the building part only, ie structure, roof, and internal flooring and woodwork. I with the help of colleagues would complete the rest.
Can I ask a builder to quote me for works with no permission and draft drawings or would it be better to get quotes once permission has been granted and drawings completed by architect.
Finally is there a ballpark figure for the kind of extension I'm looking for.
We're looking not at a full length extension but a three quarter ext.
No measurements have been taken at this stage. One more thing presumably I need to get the deeds to establish boundary?
Information would be greatly appreciated.

 

[tony1851]

Builders generally prefer to get the materials theselves, for all sorts of reasons.
Get plans drawn/planning permission first; you may find you have to alter your original plans to get approval.

 

[freddiemercurystwin]

Good builders (IMO) are always keener when they can see you have had drawings done so know there is a job in the offing and you're not just shooting the breeze.

 

[pred]

£60k Ballpark figure!!

I never quote for the bathroom suite, only the installation. All to often the builder will turn up with the cheapest thing he can get his hands on, this also includes loft conversions, my tip if you are having a new bathroom or anything else which is on show, either get it yourself or you want to see the product first.

 

[noseall]

Often people will contact me for a "feasibility" visit to see if a job is viable. If it is I then put them in touch with an architect and then await the drawings.

I will always get asked the question "how much" and reply with a vague ball park figure of £1000 p/m² for the building work.

The beauty of having an accurate (full b'regs) drawing is that everyone is singing from the same song-sheet i.e. builders and client alike. This means that if prices vary a great deal then it is down to the status of the builder and his pricing mechanisms rather than his interpretation of the job.

Building the 'watertight shell' part of an extension is commonplace and should not phase most builders though there are some that thrive on second finish items such as kitchens and bathrooms.

Separating the materials out could be contentious for some builders and it could have a negative effect upon the client also, in that who is ultimately responsible for any defects and the all important timing of deliveries etc.

 

[razorback]

We get our first quotes tomorrow.
I must clarify, it is an elevated side extension with 1 bedroom and 1 study, 2 windows and 2 rads retaining driveway leading to garage.
Shell, flooring, pitched roof and studs as well as above only.
I believe 60k to way way too steep.
To give you an idea google 9 Howard court Middlesbrough. They have an extension that we are after.
Approximate measurements
Length 5.95metres
Width. 2.94metres.

 

[^woody^]

Between £30 and £40k.

 

[razorback]

Hi woody,
Did you google 9 Howard court Middlesbrough?
I've yet to be convinced that its going to cost even that because it is not a full extension and its going to be a shell plus a few other jobs. It's like a "half extension"
The extension is not going the full height so essentially it's on stilts/pillars so that access to the garage at the rear can still be achieved. The garage is separate it is not integral.

 

[pred]

I've just Googled it and it's a lot smaller than I envisaged, I think Woody is not far out at £30k and spot on at £40k.

 

[razorback]

Thanks all.

 

[^woody^]

I did see it.

There will be some nonstandard work in the ground, and for the piers and structural supports. Plus additional design fees.

So it's not just a case of deducting ground floor walls and the floor. It won't be too far off the cost of a two storey - more than 75%, perhaps 85%

 

[razorback]

I will post results of completed extension, plus work of builders other works. It is a lot less than quotes on here....a lot less. Wait out for more info.

 

[pred]

Don't pay anything in advance, if he wants money for skip blocks etc before anything has been done then say you'll pay for it on card, stage payments and hold a bit back till all is done and dusted.