What to gather first
Start with measured roof area rather than the floor area of the house. Ask each bidder which removal, decking, flashing, ventilation, and access items are included before entering allowances. The roofing cost guide explains how to compare those scopes.
Build a roofing budget scenario
The starting values are illustrative assumptions, not Portland price data or a contractor quote. Replace them with measured roof area and project-specific allowances. Installation scope varies: avoid counting removal or repairs twice if a bid already includes them.
Illustrative subtotal: $13,000
Formula: roof area × installation allowance + removal + repairs + other allowances. Permit and review fees are excluded unless you enter them under other allowances. Check which office and project rules apply before budgeting those fees.
A written roofing bid should explain measured area, included work, exclusions, and changes for concealed damage. Roof age or ZIP code alone cannot establish those costs.