Who would walk on a black roof in their socks on a sunny day?
We did just that this week at the new Taconic Regional Headquarters for New York State Parks in Staatsburgh. But the roof was white and cool, quite literally.
Back in Westchester County, we asked Tim O'Donoghue, a second-generation roofer with lots of large commercial clients, what roof color is most popular these days. “Every new roof we put on these days is white,” he reports.
The reasons are simple: a white roof saves money.
A white roof reflects more radiation back up into the atmosphere and absorbs less heat than darker roofs. That means that the roof itself undergoes less extreme temperature conditions over its lifetime.
But, more importantly, the building underneath the roof gets less hot and requires less air conditioning.
On the hottest day of the 2011 summer in New York City, a white roof covering was 42 degrees cooler than a traditional black roof.
The white roof on Taconic Region headquarters also improves the effectiveness of the new photovoltaic system, because the panels operate more efficiently when they are cooler. Solar panels help shade the roof, extending its life. So, white roofs and solar systems have a positive, symbiotic relationship.*
Lighter colors also help on the ground.
The headquarters wrap-around driveway is not the traditional dark macadam, but a porous light colored concrete. And the parking spaces are bricks that allow water to drain in between. So the driveway lowers the typical summer time “heat island” effect and has less winter icing issues a lighter colored and more permeable pavement than tradtional black top.
If you are not in the market for a new roof, there is a low-cost alternative: paint!
As President Bill Clinton noted in Newsweek in 2011, “Every black roof in New York should be white; every roof in Chicago should be white; every roof in Little Rock should be white. Every flat tar-surface roof anywhere! In most of these places you could recover the cost of the paint and the labor in a week.”
Check out the White Roof Project for more information about what is happening in New York City. Those of us in the ‘burbs can learn from the Big Apple on this topic.
So lighten up when choosing your next roof! After all, it will be up there for 25 years.
(*The renovation of this 1930s schoolhouse by the Parks Department last year set a new standard for lowering operating costs by smart planning. The building renovation efforts combine to produce a stunning low total utility bill of about 9,000 kiloWatt-hours per month for a 31,000 square foot 3 story building with 43 separately controllable heating and cooling zones. They eliminated the old fuel oil boiler and all the old air conditioners, and use a geothermal system instead. But we’ll leave that for another column.)