Define the scope
Separate building costs from land, studies, connections, landscaping and professional fees. Ask what is included, excluded or still estimated.
Leave room to make decisions
A contingency and a ranked list of choices help absorb adjustments. Their size should be set with professionals for the actual project, not a universal percentage.
Track changes
Before each change, record its cost, timing impact and who approves it. A good decision is one whose consequences are understood.
