Cool Roofs (Reflective Roofs)
Also known as: Reflective Roofs
A cool roof reflects most of the sunlight that hits it instead of soaking it in. That keeps the roof surface, the interior of the building and the surrounding air noticeably cooler.
Scientific detail
Cool-roof performance is characterized by the Solar Reflectance Index (SRI), combining solar reflectance and thermal emittance. Field studies show cool roofs can lower interior peak temperatures by 2–5 °C and reduce cooling energy demand by 10–30 %, while decreasing UHI intensity when deployed at neighborhood scale.
Related terms
Reflective Cooling
Cooling by bouncing sunlight away from a surface before it can be absorbed as heat.
Albedo
The fraction of sunlight a surface reflects — 0 is black, 1 is a perfect mirror.
Passive Daytime Radiative Cooling
A material that stays cooler than the air even under direct sunlight by radiating heat to the cold sky.
Urban Heat Island
The phenomenon where cities are noticeably hotter than the surrounding countryside.
Surface Energy Balance
The bookkeeping of energy flowing into and out of a surface at every moment.
Where this concept shows up on MEER
Related projects
- Freetown, Sierra Leone
Reflective rooftops across informal settlements.
- Pune, India
Rooftop reflective installations in dense urban housing.
- California, USA
Rooftop mirror arrays measuring cooling potential.
- Beijing, China
Urban rooftop deployments.
Related publications
Related resources
In HeatLens
- HeatLens
Interactive heat-risk assessment tool.
Explore in topic hubs
Curated collections of MEER research, projects, publications and stories that feature this term.
Passive Cooling
Everything MEER publishes on passive cooling — reflective roofs, PDRC materials, canopies, reservoir systems, projects, publications and stories, gathered in one place.
Urban Heat
The urban heat-island effect, its measurement, and how MEER's reflective roofs, canopies and pavements reduce peak city temperatures and protect vulnerable urban populations.