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House extension rough quote needed
steve m - 10/8/14 at 09:27 PM

I and my wife may have to move into my parents house due "there health issues"
so wondered, what would be the rough cost of building a second storey extension over the garage and kitchen
with a normal two pitch roof to join with the existing roof
rough dimensions would be 3 metres wide by 8 metres, house depth
the garage and kitchen were already built with the foundations to support a second storey

house is brick built in 1969 with a normal tiled roof, and the tiles are available, as we bought a few a couple of years ago

we already have plans, although 30 years old will need to be refreshed, as my parents were going to do this years ago

just a rough ballpark figure, as I have a couple of builders coming round, and just wanted to be aware!

regards

steve

snapper - 10/8/14 at 09:35 PM

The garage will be demolished and foundations dug up unless you can prove they are up to current standards
Also depends where you are in the country
But £40k is what I would expect

stevebubs - 10/8/14 at 09:50 PM

50-70k round here...assuming starting from scratch..

[Edited on 10/8/14 by stevebubs]

joneh - 10/8/14 at 09:55 PM

I did exactly this to create a new bedroom and bathroom. Re-using the garage trusses and tiles came to about 30k. Needed to have the garage foundations under filled with 1m of concrete.

steve m - 10/8/14 at 10:38 PM

Thanks, something to go on, as im clueless on this type of thing,

the garage and kitchen were added about about 1986 and were built for a second storey
but might not be up to current regs

regards

steve

loggyboy - 10/8/14 at 11:12 PM

There arent really regs for foundations, as its all based on gro6nd conditions site by site, but you will at least need to dig one or more ssmple trenches to satisfy the building control officer they are to his liking.


[Edited on 10-8-14 by loggyboy]

stevebubs - 10/8/14 at 11:14 PM

Not sure if it affects the planning permission, regs, etc but did they get planning permission for a 2 storey extension first time around?

steve m - 10/8/14 at 11:38 PM

yes they did, but as I had already left home, and then my sister did, the requirement for 6 bedrooms was not needed

snapper - 11/8/14 at 06:00 AM

You could save a substantial amount if foundations are up to it
Even more if the garage wall is already double skinned

Sam_68 - 11/8/14 at 06:09 AM

quote:
Originally posted by stevebubs
50-70k round here...assuming starting from scratch..


Really? £2,000 - £2,900/m2 for a 1st floor extension to a fairly basic spec?

Damn. We need to increase what we're charging...

Slimy38 - 11/8/14 at 07:30 AM

quote:
Originally posted by snapper
The garage will be demolished and foundations dug up unless you can prove they are up to current standards
Also depends where you are in the country
But £40k is what I would expect


That's actually what ours cost. Removal of the car port, dig the foundations, garage/utility with a bedroom on top. A huge chunk of that was the foundations, both labour and materials.

We did get quotes up to 80k, but that particular quote seemed very 'extravagant', for example they quoted HSS rates for digger hire instead of being able to use their own.

Simon - 18/8/14 at 11:16 AM

Steve
This is what we did two years ago.

The garage wall is single skin, but we put a large hole in garage floor to act as inspection pit for footings then used same hole once filled with concrete to build engineering brick pillar for steels to hold inner (timber frame) walls up. Kitchen behind garage all double skin. Brick outer.

All our materials/labour etc from start to plastered (I finished the rest) and including some remedial work to existing roof was about £28,000

ATB

Simon

Ugg10 - 18/8/14 at 11:41 AM

We did an extension but found there was one significant item that affected the price - whether the builder was VAT registered, using a larger company automatically added 20% onto the small, one-man band builder.

However, the deal I did/was offered was :

- Agreed a fixed price based on the architects drawings and my (several pages of) additional items (i.e. number of sockets,wall finishings, coving etc.)
- I set up an account at the local builder's merchants (actually 2) with the builder as a signatory therefore I owned the materials, this was topped up when it got low
- Paid all trades directly (plumber, cental heating, electrician)
- Paid the builder a weekly set amount
- Deducted the thee itmes above off the fixed price (keeping a record signed by mysefl and the builder everytime a payment was made) until either the cash was gone or in my case the work was done and there was a "ballance" payment at the end (best to work it out that way).

This worked well, kept the builder incentivised to finish the job early (maximises the balance) whilst keeping his cash flow OK but also reduced my exposure by payng for several parts directly but within a fixed price budget.

Definitely worth doing the additional items list at quotations time so that you limit the in-work changes - think many times, do once is always worth remembering. by doing this we had three quotes all within 2% of each other.

We had a double sotory extension and it came out at around £1k per square metre of floor space.

Hope this helps in negotiations.