A vital element of any construction contract is a clearly defined scope of work.
In house building, scopes of work are not commonly used and there is a heavy reliance on quotes to establish the extent of the work. Good contractors (and suppliers) will include a list of exclusions with the quote and rely on terms of trade to carry the legal aspects of a contract. This is lazy and always leads to arguments when work or goods are not executed to the expected standard.
A good Scope of Work document will reinforce to your contractors that your company is also a professional business and clearly understands its quality standards. It will also ensure there is consistency across multiple contractors carrying out the same work.
It also serves as a legal document once the terms have been agreed upon.