The component being changed
Glass-only, hardware-only and complete-frame work involve different materials and labor. Compare proposals for the same work.
Access and concealed condition
Opening size, access, finishes and damage discovered during removal can change the work. Agree how any change will be documented.
The complete proposal
Clarify removal, disposal, weatherproofing, finish restoration and completion checks before comparing totals.
Changes and exclusions
Confirm what is excluded, who approves additional work and when a revised total will be provided.
The handover
Ask which completion checks and documentation you receive and how to raise a question afterward.
Useful references
ENERGY STAR window, door and skylight information ↗NFRC performance labels ↗General guidance. Confirm the scope for your property.