Louisville Metro government is offering new rebates for property owners who install so-called cool roofs, which use lighter-colored or reflective materials and stay significantly cooler than dark roofs.

Along with other strategies like tree planting, they’re one way to help combat Louisville’s urban heat island effect.

The urban heat island is the temperature difference between urban areas and nearby countryside. It’s exacerbated by large, dark areas — like asphalt parking lots or dark roofs.

Using lighter roofing materials has been shown to reduce a roof’s temperature by more than 50 degrees Fahrenheit. A study released last year on Louisville’s urban heat island found that if both surface paving and city roofs were lightened, it would reduce the average daily temperature across the city by one to three degrees.

The new rebate — funded through the city’s budget — will incentivize homeowners to convert their roofs to lighter materials.

“Cool roofs are one of the key strategies that were identified in the heat management study that we released last year,” Metro Sustainability Director Maria Koetter said. “So this is our first dedicated program that citizens can take advantage of to install cool roofs on their properties.”

The funding is meant to help cover the difference in cost from using lighter Energy Star shingles rather than traditional roofing material. Property owners can apply for $1 for every square foot of their roof, up to $2,000 for a new residential roof.

Commercial building owners can receive up to $5,000 for a flat or low-sloped roof and up to $10,000 for a steep-sloped roof. At least 60 percent of the funding will go to council districts that are disproportionately affected by the urban heat island. Those include districts 1, 3, 4, 5, 6, 12, 14 and 15.

Koetter said the funding would be first-come-first-served, and if the program is a success, another cycle could be funded next year. For more information or to apply, click here.