Compare the installation packages
Write a common bathing-area specification, then separate the additional demolition, fixtures and finishes in a full remodel. This shows what the larger scope buys. Include protection and patching in the partial option; retaining components can still require labor around them.
Normalize the proposals
Use the same dimensions, fixtures and enclosure features for both options, then isolate the work that differs. Mark demolition, substrate preparation, connections and finish restoration as included or excluded. Ask each contractor to identify the condition that would change the recommended assembly. This exposes a real scope difference instead of treating two product labels as a complete comparison. Where either option requires specialist fabrication, identify who measures and approves those components before ordering.
How can the two totals be compared fairly?
Use a shared core scope with itemized additions for the full remodel. Mark allowances and exclusions consistently so a low partial total does not hide required restoration that appears in the full proposal.
The owner should confirm the proposed service scope and provider availability independently. This guidance does not identify an approved contractor, establish coverage for a specific property or guarantee acceptance of the project.