Begin with your building
Roof geometry, existing condition, exposure and intended use guide the comparison. Ask the project team to identify appropriate systems before comparing appearance or a headline price.
Put the same scope beside each option
Compare removal, substrate work, components, interfaces, maintenance and warranty terms. Avoid applying a lifespan or savings claim from one product to every system.
Use evidence you can check
Request named products and current documentation. Review material and workmanship warranties separately, and ask what assumptions support each proposal.