Site realities that move the number
Concealed rot, tight staging room, living in the home during work, roof pitch, and grading all affect labor and sequencing.
What the scope should spell out
Boundaries of the repair, system capacity, material compatibility, disposal, testing, and restoration all belong in writing, not left implied.
Permits, inspections, and other trades
Depending on scope, a permit, inspection, engineering sign-off, environmental test, or another trade may be needed. Confirm directly with the provider and local authority.
Planning context, not pricing
None of this is an offer to sell anything. Request a written scope specific to your property before comparing numbers.