Do you mean the general build clean on the house or just the build clean on the windows?
We look after quite a few sites for one of the bigger house builders. We subcontract the window cleaning from a general cleaning company who do all the internal cleaning apart from the windows. The general cleaning is done in 3 stages, build clean>reclean>sparkle clean. The windows are done in 2 stages, after the painters have finished we clean the windows, removing all tape from frames and cutting into the painted plaster ready for the Mastic to be applied. We then return and sparkle clean the windows in and out just before the homeowner moves in.
We work as a 2 man team and the houses take anywhere from 2 - 8 man hours to clean the windows depending on the size of the house. We clean anywhere from 2 - 12 houses per week at the moment.
It's hard work, far harder than regular maintenance window cleaning but it's work that can be done in any weather and its well paying and regular.