Renovation work? Costs???

[24again]

Obviously you don't know the house but how much roughly for the following?

New double glazed sash windows (About 20)
Rewiring a four bed detached.
Two RSJ's and sun room extension with roof lantern.
Replastering five large rooms.
Extending a doorstairs loo to include a utility room and an ensuite above.
Adding in a staircase (Already a hole for it to go up into.)
Build a new double garage.

I have rough ideas in my head but have no idea if they are realistic!

We are doing similar, in London £120,000.

I have reread it and now think £140,000.

No idea about the other items listed, but the rewire should cost about £5-6k, dependent on number of light fittings.

That amount allows for light light per ceiling, extra down lights are roughly £50 each.

That is a rough price for our area anyway, may be cheaper elsewhere.

Windows £20k if you shop around and negotiate.

Rewire £7k

Extention £70k (very size dependent, my sisters just had similar with RSJ's excluding kitchen was 55k in much cheaper area)

Replastering £400 per room so £2k

Replastering to patch wire chasing £1k

Ensuite/ loo/ utility £10k

Staircase £10k (very plain off the shelf and could be £2k)

Double garage £20k. (Wooden shed style would be more like £5k. Fancy with wiring and storage loft could be £50k)

With no specs for stuff or real detail I guestimate £140k + contingency of 20% for all those unknowns so nearer £170k