To push out the ground floor side (gable end) wall of a house to extend a lounge and kitchen. Wall to go out about 8-10′, and along the full depth of the house (about 30′). The ground slopes away at the side of the existing wall, by a couple of foot in total, so that would need to be taken into account by the new footings/walls etc. New section to have slopey roof, not flat, with a couple of skylights.

No plumbing/drains or anything need to move.

whayareckon?

£35k inc prof fees

edit: vat on top of course

Without a decent set of drawings and a site visit you’re not going to get a real world quote.
There are many things to consider. Accesibility,laydown and storage area, how soon do you need it?, wereabouts is it?etc, etc,etc.
Once these and many other factors have been allowed for can you start looking at your budget.

Feels about right ^

Rule of thumb would be circa £1,500 / sq metre

Is this just empty space (ie, just basic work doing, but assuming you’ll need lighting, power etc)? If so I would say around £30/£35k too – but if you need to spend money bringing your electrics up to speed (to get sign-off), or if you need to match specific bricks/tiles etc, you need to plumb in central heating, you want expensive skylights or non-standard uPVC windows etc you could add another £10k

i had decided to pitch in with £30k before reading the spec/thread.
not saying that builders are predictably bad with numbers but…..

i would go further and say that it will end up costing just shy of £40k, what with VAT and additions and the cost of blah going up which nobody could foresee and you agree to take half the hit on it.

My experience of builders is take the estimate and double it.

Downside of quotes is if it starts to go pear shaped they can ask for more money and if they don’t get it they can walk.

Might be cheaper to move 🙂

For a budget take somewhere between £1000/m² & £1200/m² depending on the level of finish (based on experience in Yorkshire) – I suspect that down in that there south you could somewhere nearer slackalice’s figure

For what it’s worth, it cost me (5 years ago) £28k for a 8ft x 12ft pitched roof single story extension, but that included internal work, supporting two load-bearing walls, plumbing for a downstairs toilet (full sized foul pipes) and we also needed to move the electricity to the other side of the house.

My experience of customer’s is that I can give a ball park figure to establish a budget expectancy, in the region of £1,500/sq m. If that budget expectancy is deemed affordable, a more detailed quote is then prepared, often with contingencies noted for unforeseen things that can and do crop up. Final quotes with a complete wish list can get up to £2,200/sqm easily.

However, IME, once the work starts, things like the basic fixtures and fittings are upgraded. For example, basic MK plastic light switches are changed to much more expensive metalled ones. Similarly, once the customer gets an idea of the actual new space available, additional requirements that were initially dismissed by the customer, become desirable. Likewise, final decoration, that was first agreed to be completed by the client, also gets added, ‘because we are there, so you might as well do it too please’.

This is easily managed with frequent budget reviews and the additional desirables/wants are itemised against the original quote.

The biggest reason for the situation as described by richc, is the customer going for the cheapest quote, with many of the required bits to provide a finished build not actually included in the quote. So there are indeed some unscrupulous builders. Get at least 3 quotes and if one is significantly cheaper, buyer beware! I am generally not the most expensive but not the cheapest either, but I include everything that can be foreseen as far as I am able. This does mean I do not get every job I quote for, because I haven’t provided the cheapest quote. For those, I am happy not to get as it generally means that the client cannot actually afford what they want.

Cheers all, looks like 40k is the figure to have in mind.

Very useful, ta.

Where are you based slackalice? After a quote on a small extension and I like the cut of yer jib.

HI will, bless you and thanks 🙂 Most of my work is Hampshire – Meon Valley, Petersfield, into W Sussex.

Most of my work is Hampshire – Meon Valley, Petersfield, into W Sussex.

So my extension in West Yorkshire, currently going through planning, might be a bit too far for you to travel to each day, slackalice. 🙂 Pity, you seem like a good guy!

And I’m in West Yorks too… bah!

I’m looking at build costs of about £30k (a shade under) for a 3m double width single stores extension including second fix and fitting of, but not supply of, kitchen and flooring.

I’m just waiting for a revised quote because due to the way the drains are I need to go out over the drains, so maybe an extra 0.3 – 0.5m with some roof modifications. The builder reckons it shouldn’t add too much extra on as there is some labour intensive work they don’t need to do now I’m building over the drains. If I can pull it in for 35k I’ll be happy.

The biggest reason for the situation as described by richc, is the customer going for the cheapest quote, with many of the required bits to provide a finished build not actually included in the quote. So there are indeed some unscrupulous builders. Get at least 3 quotes and if one is significantly cheaper, buyer beware! I am generally not the most expensive but not the cheapest either, but I include everything that can be foreseen as far as I am able. This does mean I do not get every job I quote for, because I haven’t provided the cheapest quote. For those, I am happy not to get as it generally means that the client cannot actually afford what they want.

I agree with that, most people go with the cheapest and then act surprised when it screws up.

Some builders do take the piss with everything is an extra. I had one diabolical builder who tried to add on tool hire for their own tools + delivery to drive them to site! And he wasn’t the cheapest.

Mind you he did managed to cause 30K’s worth of damage before I fired him!

We had an extension of similar size to the OP.
It comprised removing, rebuilding, kitchen & shower room.
First ballparks were £20-£25k, we spent IRO £70 k before we’d finished. SOmehow I’d expected that.