building-cost estimate please

[tildakovach]

we are looking at an almost derelict house to buy not far from Stroud-Glos;
1) is it cheaper to knock it down and start afresh (I think it is) or 2) extend/repair?
How much can I reckon on knock down + rebuild? I know it is like "how long is a piece of string" Here are some ideas I should like to install:
- heat pumps - solar panels -aluminium windows -underfloor heating for the heatpumps, and onlyk few rads; -tv and telephone points in all rooms - total are (incl integrated garage +workshop) 244sqm - top notch insulation -own well with pump for baths, showers,carwash/garden, wcs, washing machine, i.e. all non-drinking taps; -satellite dish - i myself do all decorations (papering/painting/decorative plasterworks etc) many thanks for any reply in advance!!!

[buildersmate]

If you are serious about this type of project I suggest you spend about �20 on this book.
http://www.amazon.co.uk/Housebuilders-Bible-In siders-Construction-Jungle/dp/0952485249
It is not a technical book but contains a massive amount of information helpful to self-builders on costing their projects.
The answer to the simple part of your question is that it is invariably cheaper to knock down and rebuild. It costs an incredibly small amount to demolish and clear a site - the order of a few thousand pounds. Then you can start afresh, putting prpoer foundations in, constructed walls to current insulation standards and so on.
If you renovate and refurbish you are constantly having to account for the deficiencies in what exists and make allowances for them.

[tildakovach]

Thank you, BM, it was very helpful.
One more quicky question:
which is the most cost effective build: stone/reconstituted stone, (I think expensive), brick/breeze block (ditto) timber- frame with interior brick/breezeblock walls? (I think this one)
expressed in percentage terms by how much cheaper is it to build with timberframe than let us say breeze-block?
Thank you once again for a very proffessional and quick advice. I shall get the book too!
P.S. Gloucester Book Depository works together with Amazon, but is cheaper! operate only on -line.

[buildersmate]

You will find some up to date figures in the book! (mine's out on loan).
Stone is undoubtedly the most expensive to buy and to lay.
Timberframe houses invariably have timber (studwork) walls designed as part of the frame structure. They then generally have a brick external skin, or a blockwork outer skin rendered. I've never heard of a timberframe house with blockwork internal walls.
Timber and blockwork generally don't work out much between them. Timberframe is often more expensive in pure purchasing terms, but the structure goes up in 2 weeks or less, meaning the roof can then be put on, and the internal trades (electrician, plumber, chippie) can start their work whilst the external skin is being done by brickies - so there are savings in time and hence project management costs and overheads. So there isn't much between them in overall cost.
You will have noticed that major housebuilders are using timberframe these days - they aren't in the habit of doing things more expensive for no reason.

[tildakovach]

Thank you BM, book is on it's way to me via a sub of Amazon for just �7, second hand 7th edition.
Thank you for your tips, and comprehensive answers !
regards, T.