Iranian architects have developed a Concave Roof system to collect rainwater in arid climates with low precipitation, helping cool buildings in hot and dry regions of the world. The water can in turn be filtered for drinking or integrated into interior graywater systems.

These systems help reduce reliance on artificial air conditioning (or work were it is unavailable). They could ultimately help keep people in their home regions who might otherwise have to move due to climactic changes.

BMDesign Studios’s addresses rapid evaporation with the bowl-shaped roof additions, designed to channel even the smallest amounts of accumulated rain, coalescing them into drops big enough to harvest before they evaporate.

These inverted shells also provide shade while allowing air to pass between upper and lower roofs, acting as a cooling system in the process.

Reservoirs tied into the system are situated between building walls to take advantage of the thermal capacity of the water to regular interior temperatures.

The courtyard and circulation spaces are also sunken to further cool the complex. Temperatures are higher and precipitation in parts of Iran is as much as 2/3 lower compared to global averages, so every drop counts.