What system is actually being offered?
EPDM is a rubber roofing membrane; bituminous coverings use bitumen and reinforcement layers. Both families contain different products and installation methods. A quotation naming only the material leaves important questions open. Ask how seams, edges and penetrations will be detailed in the proposed system.
Tell us about your situation ↗Does it suit the existing roof?
Substrate condition, moisture in existing layers and surrounding junctions influence the choice. Available height at a door threshold or rooflight can matter too. A roof full of details needs different preparation from an uninterrupted rectangle. Ask why the complete build-up is appropriate and what preparation the contractor has included.
Make the scope comparable.
Compare removal of old layers, waste handling, substrate repairs, insulation, edges and rainwater outlets. Ask how completion and any warranty terms will be documented. A general lifespan found online is not a promise for a particular roof. Start with matching scopes, rather than choosing from square-metre prices alone.