item 1-ground floor
concrete floor BRC.... size or brc ? A6, A8 ? Cq spec or BS spec
concrete floor brc - quotation include damp proof membrane? before concreting?

carporch roof slab- waterproofing?

plaster ceiling-  type ? plaster of paris  or gypsum?
for outdoor ceiling or toilets /laundry area- proposed gypsum moisture resistance-example USG BORAL WETSTOP MOISTURE RESISTANT.

Staircase- ask the contractor to confirm numbers or step - width and height of each step.. do not exceed the maximum requirements under UBBL...
staircase construction is tricky - need to properly design and confirm tread and riser.... i have seen staircase construction that are just nonsense.
Tripping Hazards and Safety Concerns: Incorrect riser heights can lead to tripping hazards and safety concerns, especially for individuals with limited mobility (old folks)

This are some input when i glance through your quotation.

cheers mate
Izwan
www.archidstudio.com