Why builders clean is a different job
Ordinary cleaning removes soil from surfaces that are otherwise finished. A builders clean deals with residues bonded to brand-new finishes that are easy to ruin: cement splashes on tile, grout haze on porcelain, silicone smears on glass, plaster dust ground into unsealed stone, adhesive from protective tape on powder-coated aluminium, and paint spots on everything.
Each of those needs the right method. Grout haze comes off with a mild acidic wash on tile that tolerates it, and takes the polish off natural stone that does not. Blades will lift paint from glass, and will scratch coated glass permanently. Protective film left in UV for months bakes its adhesive on and needs solvent and patience rather than force. Getting this wrong on a handover is expensive, because the remedy is replacement rather than recleaning.
The other difference is that dust is everywhere, not just on the floor. It sits on top of door frames and ceiling grilles, inside cupboard carcasses, in shower channels, in switch and socket boxes, behind skirting, and in the AC ductwork. If it is not removed at the right stage it circulates as soon as the system runs, and the client sees a film on every surface a week after moving in.

