Blog & resources
Understanding cool roofs before starting a project.
Our guides, translated from the French blog: what the regulations require, which incentives really apply, how the system performs and how it compares with the alternatives.
Regulation
Regulation
- French tertiary decree and commercial leases: who declares, who pays, what to negotiateFrench tertiary decree and commercial leases: who declares on OPERAT, certificate appended to the lease since July 2026, who pays for works, the cool roof.
- French tertiary energy audit: who must comply, what it contains, where the cool roof fitsMandatory French energy audit from 2.75 GWh a year: content (NF EN 16247), link with the tertiary decree and OPERAT, and the cool roof in the action plan.
- Heatwave plan for French schools: framework, thresholds, measures and the role of the roofHeatwave plan for French schools: Météo-France warnings, 2026 ministerial plan, measures, passive building solutions and up to −30 °C on the roof surface.
- HQE, BREEAM In-Use, LEED O+M: summer comfort and heat islands in building operationHQE in operation, BREEAM In-Use V6, LEED v5 O+M: summer comfort and heat island credits (SRI 82 new or 64 aged), and what an SRI 120 roof brings.
- French tertiary decree and cool roofs: OPERAT, −40 / −50 / −60 % targets, the roof's roleFrench tertiary decree: 1,000 m² threshold, −40 % by 2030, −50 % by 2040, −60 % by 2050, OPERAT, absolute or relative, penalties, cool roof contribution.
Incentives & funding
Incentives & funding
- Financing a reflective roof in French co-ownership: shares, works fund and VATFrench co-ownership: who pays for a reflective roof? Ownership shares, works fund, voting majorities, 10 % VAT and what MaPrimeRénov’ does not fund.
- Air-conditioning savings: how a cool roof cuts the bill by 15 to 40 %How a reflective roof reduces air-conditioning consumption: 15–25 % in French zone H1, 20–30 % in H2, 25–40 % in H3. Physics, factors, measurement.
Technical
Technical
- Bifacial panels and solar canopies on a bright roof: albedo, output, temperatureBifacial panels on a bright roof: albedo, published gains (IEA, Applied Energy), module temperature coefficient and compatibility with a cool roof.
- Carbon footprint of a cool roof: manufacture, application, avoided cooling, albedoManufacture (French EPDs), application, air conditioning avoided up to −40 %, albedo (LBNL): a cool roof’s carbon footprint over 20 years, no invented figures.
- EPDM membrane and cool roof: talc, adhesion test, primer and singular pointsEPDM and cool roofs: black rubber at 70 °C, talc, adhesion test, primer, seams and upstands. 95 % reflectance, SRI 120. Free study within 48 h.
- Heat and productivity at work: thresholds, errors, accidents and building leversILO, WHO, INRS, studies: −2 to −3 % productivity per degree above 20 °C, more accidents, French employer duties and what the building can change.
- Reading a reflectance, emissivity and SRI test report: standards, new and aged valuesReflectance (ASTM E903), emissivity (ASTM C1371), SRI (ASTM E1980): reading a test report, new and aged after 4,000 h, pitfalls of figures with no standard.
- Infrared roof temperature measurement: method, common errors and reading a reportEmissivity, distance, angle, time, control area: how to measure a roof’s temperature by infrared and read a handover report (−29 °C measured).
- Livestock heat stress: benchmarks by species and passive building solutionsLivestock heat stress: dairy cows from a THI of 68, broilers above 23 °C, and the passive solutions for the building, roof included.
- Thermal resistance R, U-value: how to read a roof’s thermal reportR = d/λ, U = 1/(Rsi + R + Rse): reading a thermal report, what insulation does and does not do against summer heat, and what 95 % reflectance adds.
- Steel deck: condensation, corrosion, fixings — the diagnosis before a cool roofSteel deck: dew point, anti-condensation felt, rust at the overlaps, corroded screws and washers, diagnosis before a cool roof. Free study in 48 h.
- Supermarkets and the cold chain: temperatures to hold, and what the roof changesRegulatory store temperatures (−18 °C, +2 °C, +4 °C), refrigeration’s share of a supermarket’s electricity, and up to −30 °C on the roof. Study in 48 h.
- Cool roof in winter: do you lose heat and pay more for heating?Cool roof and winter: low sun on the façades, weak sunshine, insulation that blocks the gains. Why the annual balance stays positive everywhere in France.
- Cool roof maintenance and durability: what makes a reflective roof lastCool roof durability: SRI maintained after 4,000 h QUV, 20-year conventional service life (French CEE sheet), low-pressure cleaning every 12 to 15 months.
- Urban heat island (UHI): how cool roofs cool down citiesUrban heat island: up to 10 °C of difference at night between city and countryside. How an SRI 120 cool roof cools the district and protects your building.
- Environmental impact of cool roofing: what a reflective roof really changesEnvironmental impact of cool roofing: urban heat island, avoided air conditioning, longer-lasting waterproofing, water-based product. The real effects.
- Heatwave 2026: follow the alerts, understand the thresholds, protect your buildingHeatwave 2026: where to follow Météo-France alerts, what a heatwave is and how to protect a building, up to −30 °C on the roof with a cool roof.
- The reflective roof: the anti-heat solution for your buildingReflective roof (cool roof): how it works, up to −30 °C on the roof surface, benefits, types of reflective roofs, installation and maintenance.
- The Solar Reflectance Index (SRI): why it makes the difference in cool roofingSolar Reflectance Index (SRI): definition, how to read a product data sheet, PrimaTherm® SRI 120 retained after 4,000 h QUV. How to compare roofs.
- White or coloured cool roof: what difference in performance, and when to choose a tint?White cool roof (95 % reflectance, SRI 120) or light tint: what colour changes, what French planning rules and heritage architects impose, how to choose.
Comparisons
Comparisons
- Reflective coating or white membrane: which cool roof for your roof?Cool roof coating or white PVC/TPO membrane? Waterproofing, substrates, pitch, application, durability, maintenance: the comparison to choose for your roof.
- Cool roof vs green roof: performance, constraints, relative costs, combinationCool roof or green roof? Temperature, structure, water, biodiversity, maintenance, regulation, combining the two. An even-handed comparison for decision-makers.
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