Step 01Align the scope first
Check whether both proposals describe the same plan, user capacity, glass area, heating type, interior equipment, exterior cladding and level of integration. Otherwise you are comparing different projects.
Ask for one clear page listing what is included and excluded.
Step 02Do not compare wall thickness alone
Total thickness says too little. Ask for the full wall build-up: interior lining, air layer, vapour control, insulation, structural frame, ventilated cavity and exterior finish.
Ask how floor, wall, roof, glass and door junctions are resolved. Condensation and thermal bridges occur in details, not in the marketing name of a panel.
Step 03Equipment needs a name and an owner
The proposal should identify the manufacturer and model of the heater, controller, infrared emitters, Combi system, chiller or water-treatment equipment. “Premium heater” is not a specification.
It is equally important to state who sizes, connects, commissions and services each component.
Step 04Include the site
| Question | What must be clear |
|---|---|
| Base | Who verifies capacity and carries out preparation |
| Utilities | Required power, water, drainage and work boundary |
| Delivery | Transport, unloading, crane and access |
| Installation | What is included and who coordinates contractors |
| Handover | Testing, instructions and documentation |
Step 05Warranty, service and maintenance
Ask for warranties by component, a service contact, expected availability of consumable parts and a maintenance list. One broad “20-year” promise is less useful than clear conditions for structure, heater, controls and cladding.
For a project outside the supplier’s home country, confirm who actually attends the site when a fault occurs.
Step 06Red flags
- a final price without a site review or stated assumptions;
- unidentified equipment models;
- universal claims about consumption or lifespan;
- “turnkey” without a boundary of responsibility;
- a render before utilities, access and maintenance are checked;
- upselling extra elements without explaining their real use.
Step 07The strongest final question
Do not ask only “what do I get for this price?” Ask “which problem and responsibility does this proposal still leave with me?” A strong proposal makes that boundary visible before signature.