Roof Color and Energy Efficiency: What the Research Says

Every time someone's picking shingle colors, this question comes up: should I go with a lighter color to save on cooling costs? It's a fair question, and the short answer is yes, lighter roofs do reflect more heat. But Kansas isn't Phoenix. We've got four real seasons, and a roof that keeps your house cooler in July might cost you a little more to heat in January. The real-world savings depend on a bunch of factors, and the data is more interesting than the sales pitch.

What the numbers actually show

Research from Oak Ridge National Laboratory found that a white or light-colored roof can reduce cooling costs by 10 to 15% compared to a dark roof. In a hot climate like Texas or Arizona, that's a significant number. In Kansas, where we've got about four months of real cooling season and five months of heating season, the annual savings are more modest: probably 5 to 8% on cooling, offset somewhat by slightly higher heating costs. For a typical Kansas City area home spending $200 a month on energy, that's maybe $10 to $15 per month during summer. It's real money, but it's not transformative.

Attic insulation matters more than roof color

Here's what we tell people. If your attic insulation is inadequate, roof color doesn't matter much. A dark roof with R-49 insulation in the attic will perform better than a light roof with R-19. The insulation is the thermal barrier. The roof color affects how much heat reaches the attic, but the insulation determines how much of that heat actually gets into your living space. Fix the insulation first, then worry about shingle color if you want to squeeze out a few more percentage points.

Cool roof coatings

There's a middle ground worth mentioning. Some shingle manufacturers offer "cool roof" rated products, shingles in darker colors that use special reflective granules to bounce back more solar radiation than their color would suggest. You can get a charcoal-colored shingle that reflects nearly as much heat as a standard light gray. These cost a little more but give you the aesthetics you want without the full thermal penalty. CertainTeed's Solaris and GAF's Timberline Cool Series are both available in the Kansas City market.

Bottom line, pick the color you like. If you're torn between two colors and one is lighter, go lighter. But don't choose a roof color you hate just to save $15 a month. If you want to talk through the options, give us a call at (913) 954-4501. We'll help you balance the aesthetics with the practical stuff.