Help with rough idea for extension & other works costs

[Weegle]

We are in the process of buying a house, surveys been done etc and we're now at the stage where people are haggling back and forth following what each survey has thrown up. We therefore need to ave a more accurate idea of what we need for the work that needs doing to the "project" we are buying. It's an Edwardian red-brick semi with a 1920's ground floor extension (bathroom). We want to knock off the back and build a double storey extension which would result in 3 bedrooms & a bathroom upstairs, then a larger kitchen, WC and extra room (study) on the back. The extension would be approx 3m x 3.5m. The whole house needs a new damp proof course and re-plastering (we've been quoted £2000 for this but that includes walls which would be knocked down with the extension). The brickwork also needs re-pointing, some reparation work to one of the chimney stacks, the wall ties need replacing, new windows throughout (although that isn't urgent), central heating needs to be installed and a new fusebox and wiring to the extension. The extension will also include a new kitchen and bathroom so there's those costs involved. I'm guessing we could use an architectural technician as we know what we want to do, just need someone to draw the plans. We've done a rough tot up of what we think but I'd be grateful if anyone could give me their rough idea of figures as it would help us now decide what to push them for/what to concede on for ours. If I've left out any vital info let me know! The damp proof course came as a surprise (and the current owners have invalidated their guarantee by not replastering correctly) so the practical side of that rather than the money is what is annoying us as it will now mean instead of us being able to camp in the two rooms unaffected by the extension for the most of the duration of the works we are now going to have to move out completely at some point meaning additional expense and of course upheaval. I'd be very grateful if anyone could help??? We are in the south east.

Just renovated our Edwardian semi...

As a guide, we had a small-ish single storey extension (to the kitchen at the back of the house) which cost £25k including fitting of new kitchen, all electrics / plumbing, plastering & decorating, flooring etc - but didn't include new doors and windows, which were an added £4k)

First things first:

£2,000 for damp proofing and re-plastering a whole house seems exceptionally cheap to me. Have you got several quotes on this? In fact, on all the work?

I'm unclear about your extension - it's double storey - how many rooms/how big?

Are you planning on using an architect or master builder to project manage this for you? That will affect the cost big time, but may be a cost worth considering for such a big job...

Is the house in good nick? Extension aside, does it need rewiring, new kitchen etc. And is this reflected in the asking/agreed price of the property?

Also, don't underestimate how much added expense is involved in moving out while works are going on. If works run over, the costs will mount (although I'm not trying to put you off doing this. We moved out for 3 months when the worst of the extension was going on...)

Thank you...

The quote for the damp proof course is by the people who did the original one (which would be covered by the guarantee if the current owners had replastered correctly). I have also had this same company recommended by two other people, so feel happy with that.

The extension would be double storey - the downstairs would replace current kitchen (and make it larger), add a WC and a room at the back approx 6ft x 12ft. The upstairs would comprise a bathroom and a double bedroom. Overall 3m x 3.5m approx.

Hadn't considered whether to use someone to project manage. I had originally thought No, I am quite good at that sort of thing but maybe I would need to - what would that cost?

No the house is not in good nick - and is massively represented in the price and how much we have knocked it down already. We agreed on the price before getting the additional damp survey done. All the other things that our structural survey picked up are things we had anticipated and therefore reduced their price accordingly. But as I say the damp proof course is so much more than the cost - because of the replastering of the ground floor room at the front which we hadn't anticipated (without the damp problem we would have had one ground floor room and one bedroom unaffected by the building works, now we'll only have one upstairs room). It doesn't need a new kitchen but it is very small and in the back of the house which would be knocked down for the extension.

We have somewhere free of charge to move to during holidays but term time would be an issue because we need to remain local, but not essential as we're talking pre-school not school. We originally anticipated that DS and I would move out for 3 months and DH camp during the weeks, which equates roughly with what you're saying.