01
The assembly, not just the finish
Unit supply is different from installed-opening scope. Custom sizes, glass, panel configuration, hardware and exposure selections change the product; headers, flashing, drainage and finish restoration change the building. Compare like-for-like unit schedules instead of counting every opening as one interchangeable item.
NAHB · homeowner remodeling preparation02
Ownership and maintenance
Include access to mechanisms and compatible maintenance instructions. Replacement glass, screens and proprietary fittings can have different service paths. A low-profile sill should be evaluated with exterior water management and floor transitions, not only appearance.
03
What the proposal must include
List each unit configuration, glass, finish, hardware/exposure package, screens, delivery, opening preparation, structural work, installation, flashing, sealant, painting/stucco and adjustment. Confirm whether lifting equipment, access protection and disposal are included. Owner-supplied units still require defined installation responsibilities.
04
Resolve before procurement
Approve opening details and the unit schedule before requesting comparable bids. Check local review for changed openings and the actual energy/design requirements with the team. Use direct system allowances in the cost model and avoid an invented universal per-window rate.