How's this for a garage conversion 'spec'?? <long alert>

[LittenTree]

Having been roundly 'advised' to get this done: Here it is!

Spec for Garage Conversion, xxxxxxxxxxxxxxxxxxxxxxxx

Divide existing integral garage to make small sitting room plus small garage space, keeping existing up and over garage door.
New room to be 2.4m x 3.6m x 2.4m high minus new wall, ceiling and floor cladding thicknesses; garage area left raw (ie not plasterboarded) but neat.

New dividing wall will need to be a fire wall (30mins).
Construction of this to be either block, with plasterboard on 'room' side; or
100mm frame, in-filled with Celotex and 'pink' plaster boarded both sides. Tied onto existing masonry.
New foundation needed to support new fire wall if block work used? Yes / No?

Floor: Floating floor with required DPCs, to level of hallway floor with small threshold as per rest of downstairs. Battens and Celotex. Glued Tongue and groove chipboard. Will be underlayed and carpeted by ourselves.

Walls: Wall against 'External wall' will need battens to cover over pipework, plus plasterboarding over; other walls can have plaster board 'dotted' onto the existing blockwork. Discuss need for Celotex insulation on 'external' wall between battens (Note- existing double skinned wall).

Separate quote for painting.

Ceiling already plasterboarded. Need advice as to whether there will be any insulation between existing PB and floor of bedroom above. (probably not!)
Options: remove plasterboard, celotex/insulate, replasterboard; or batten, celotex and plasterboard onto existing plasterboard (will lower ceiling by 12ish cms)?- to be discussed.

Coving
Skirting board

Window: as per rest of house's style. 1550 wide and high.

Electrics: Four double sockets, brushed metal as in kitchen
Two uplighters to match living room on dimmers/ us to supply uplighters, switches, plug front plates
Utilitarian wall light on wall of 'new' garage area. Will need wiring in. Electrics already in place. Us to supply light unit.

Door: new internal 6 panel door as per house doors. Rehang inwards. Do they come painted?

Radiator - plumbing ready to go ('spur' through wall from hall radiator through the wall). Need to discuss radiator options (small/modern!)

Box up gas (Potterton. Do we need a CO detector?) and fuse box, kitchen cabinet style boxing.

Questions:
We will obtain planning permission.
Do you need actual drawings beyond a line drawing showing dimensions?
Who will oversee the build and take final responsibility for the project?
Time frame? (PP will take around 8 weeks)
Contracts?
Payment instalments?
Is everyone insured?
Please quote separately for all internal decorating.( Wall, ceiling, coving, skirting boards, door, door frame.)

I also enclose a simple diagram to show the position of the new internal wall.

Would you add anything? Bear in mind builders would hopefully come and visit us and get a copy of this!