What if your house could keep itself cool — and collect its own drinking water — without using a single watt of electricity?
Researchers at the **University of Sydney**, in collaboration with startup **Dewpoint Innovations**, have developed a material that does exactly that. It looks like paint. You apply it like paint. But it behaves like something out of science fiction.
The coating reflects up to **97% of incoming sunlight** — dramatically more than conventional white paint — while also radiating heat away from the building's surface. The result: indoor temperatures drop by **6 to 11 degrees Fahrenheit** compared to outside air temperature, even under direct sunlight. No air conditioning. No energy consumption. Just physics.
But that's only half the story.
**It Also Makes Water**
When a surface is cooler than the surrounding air, moisture condenses on it — exactly how dew forms on grass overnight. The coating is engineered to exploit this effect at scale.
During trials conducted at the Sydney Nanoscience Hub, the coating captured atmospheric dew on **more than 32% of days tested**. Under optimal conditions, it harvests up to **390 millilitres of water per square metre per day**.
Do the maths: a 12-square-metre treated roof section — roughly one quarter of a typical carport — could produce enough water to meet the basic drinking needs of **one person per day**.
**The Science Behind It**
The coating is made from a polymer called **polyvinylidene fluoride-co-hexafluoropropene (PVDF-HFP)** — a material with microscopic pores engineered into its surface. The pores help scatter incoming light (driving the reflectivity) while the cooled surface below creates the temperature differential needed for moisture condensation.
This is a significant departure from conventional reflective coatings, which typically rely on titanium dioxide particles. The new coating survived **six months of continuous outdoor exposure** in the harsh Australian sun with no measurable degradation.
**Who Needs This Most**
The technology is most urgently needed in two overlapping groups of places:
- **Urban heat islands** — dense cities where buildings trap and re-radiate heat, pushing temperatures 5–10°F above surrounding countryside, increasing air conditioning demand and heat-related illness - **Water-scarce regions** — areas where drought, infrastructure failure, or geography limit access to fresh water
Across the Global South, these two conditions frequently overlap. Billions of people face both excessive heat and water insecurity simultaneously.
Dewpoint Innovations is currently developing a water-based formulation of the coating that can be applied with a standard roller or sprayer — no specialist equipment, no complex installation. The goal is a scalable, off-grid solution that communities can apply themselves.
> *'This is about providing sustainable, low-cost, decentralised sources of fresh water — and reducing cooling loads — simultaneously.'* > — Research team, University of Sydney
**What Comes Next**
The team is working toward commercial release. The water-based application formula, once finalised, would make global deployment practical at scale — in rooftops, walls, and structures anywhere in the world where people are too hot and too thirsty.
A coat of paint. Cooler rooms. Clean water from the sky.
The future of building materials might be as simple as a roller and a bucket. ☀️💧
*Sources: University of Sydney · Fast Company · Anthropocene Magazine · Positive News (November 2025–2026)*