A coating is enough if the flat roof's waterproofing is sound and the aim is better thermal protection and less summer heat. A new build-up is the right choice if the waterproofing itself has reached the end of its life. A survey of the property before the quotation settles this.
For metal roofs there is the roof coating ECR Roof. How much roof and attic-floor area your house has is shown by the address calculator in the 3D model: select the roof, click "flat roof from outside" or "roof slope from inside", apply the area. Roofs for photovoltaics can also be selected there.
Evidence
CE marking to EN 15824 (declaration of performance PSC250T-2026-01) · TÜV NORD Verified Product, mark ID 141649 · U-value guarantee per package · Measurements · All evidence and case studies