Empire,
I can't remember the contract you're talking about. Are you sure you're not confusing it with this thread:
http://www.cleanitup.co.uk/smf/index.php?topic=6234.msg46204#msg46204In my limited experience, with commercial work you don't have a 'contract' in the form of a document. It's more of an agreement between you and the person responsible for the building.
However there was a threads - a long time ago - where I remember someone saying they produced a 'Contract of Works' agreement, in order that everyone knew the score when it came to what was being cleaned, frequency of cleans and method of payment.
Tosh