Details matter, even if they’re small and seemingly superficial. When it comes to choosing a roof color, the decision has more weight than you think, and it certainly goes beyond looks or curb appeal. The color of your roof translates to how it will perform in the realm of energy efficiency. After all, the roof is responsible for reflecting the UV radiation and keeping your home’s temperature regulated—cool in the summer and warm in the winter. Ruminating on your roof color isn’t a trivial decision, it’s a scientific one.

What’s a Cool Roof?

A cool roof sports a lighter color, one that’s shades away from the traditional midnight-black asphalt or dark wood shingle styles that’s been popular for so long. Cool roofs rely on something called the “albedo effect”, a phenomenon where light and heat are reflected off of lighter surfaces as opposed to being absorbed by darker surfaces.

Cool Roof Colors

A roof that absorbs heat is typically black or falls along the darker side of the color spectrum. For a cool roof, one that deflects UV radiation and discourages heat retention, go in the opposite direction the spectrum—white.

White is the best color for energy efficiency because of the albedo effect. With a white roof, or a roof with a color that has similarly lighter hues, the sun’s rays are reflected instead of absorbed. White—or light—roofs are proven to be energy efficient with a drastic reduction of electricity in hotter seasons and temperature regulation for a comfortable atmosphere inside the home.

You’ll notice when you change your roof color to white or a lighter shade that your utility bills won’t be nearly as expensive. Your AC unit won’t have to work as hard, which extends its lifespan.

Dangers of Dark Roofs

The albedo effect is so effective that cool roofs can decrease their temperatures on a hot day by 50-60 degrees. Alternatively, pitch-black roofs that have the traditional asphalt shingles can reach 150-175 degrees on an intensely hot summer day. Consider this extreme temperature change on a large scale and you’ll get something called a “heat island effect”. Large cities with condensed structures like buildings and roads absorb the heat thanks to asphalt coatings and dark roofs, making the entire city warmer than that of the outlying areas, thus creating a heat island effect.

Heat islands don’t just create a warmer city. There are several ways this heat absorption can negatively impact the environment:

• Increased energy usage: the hotter it is, the more energy it takes to cool buildings. Air conditioning and electricity usage work overtime to help cool the effects of a heat island.
• Greenhouse gases: with so many asphalt roads and dark roofs, the heat island effect can elevate greenhouse gas emissions and air pollutants.
• Human health: heat islands make the days insufferably hot and the nights not as cool as they should be, causing higher levels of air pollution. Heat-related health issues like cramps, heat exhaustion, heat strokes, and respiratory issues occur when the temperatures are continually spiked.

When Dark Roofs Make Sense

A dark roof isn’t always a negative thing. For homes in colder climates that don’t experience the extremes of a hot summer or year-round heat, a dark roof makes sense. A black roof with asphalt shingles will absorb the heat of the sun, so if you’re in an area that is cold most of the year, a dark roof is something you’ll need to help heat your home and decrease energy usage by giving your furnace a break.

Promoting Your Roof’s Energy Efficiency

Whether you’re looking to replace the roof in its entirety or wanting to decrease energy usage, there are plenty of solutions to promote overall energy efficiency in your roofing system.

Insulation: insulating your roofing system is one of the most beneficial things you can do to help keep it cool during the summer and warm during the winter. Any DIYer can insulate their attic in a matter of hours.

Sustainable Re-Roofing: