Pricing by the Sq m/ft etc is fine for most commercial work, but not really appropriate for domestic properties. It is good for obtaining a consistent price, but you will have problems later on.
Consider this:
House 1. is a 1,500 sqft 3 storey, 3 bed, mid-terraced house. As well as kitchen, living room etc. It has a family bathroom on the first floor, an en-suite on the second and a cloak room on the ground floor.
House 2. Is also 1,500 sqft and 3 beds, but it is a 2 storey detatched property. As well as the kitchen, living room etc. It also has an en-suite on the second floor, but there is another one on the first floor, along with the family bathroom. Downstairs there is a cloakroom and a utility room.
So, as I am sure you know, apart from the kitchen, the bulk of the work involved in build cleaning - is sanitaryware ie: bathrooms, en-suites etc.
In house 2. you have an extra en-suite and a utility room, but you would be charging the same price as house 1. for perhaps 2-3 hours more work, because they have the same sq/footage.
A simpler way to price domestics might be to start with an average for the development you are quoting on. So, if the majority of the houses are 3 bed 2 storey with en-suite, bathroom and cloakroom, set yourself a price based on the time you expect it to take to clean. Then look at all the other types of properties and raise or lower your price, depending on, for example, number of beds, numbers of floors, no en-suite, extra en-suite and so on.
Most developments only have about 10 different property types. Once you have a price for each one, simply apply them to the whole development, regardless of how many there are.
Hope this helps.
