Hot Cities and Cool Roofs

(Originally published in the September 2011 issues of Merchant Magazine and Building Products Digest.)

This summer’s heat waves have been horrendous.  Hot weather is known as a silent killer and is responsible for more weather related deaths than tornados, hurricanes and blizzards, combined.  Summer days are hotter than they used to be, setting all kinds of records, but even worse are the hot nights.  Overnight lows are also setting records for high heat, making it much more difficult for at-risk populations, such as the very young and very old, to recover. 

In cities, the problem is worsened again by something called the Urban Heat Island Effect.  Cities are paved with asphalt and built up with concrete and other materials that absorb solar radiation during the day and re-radiate it during the night.  Cities can be 15° F hotter in the daytime and 22° F warmer overnight than neighboring suburbs.  More city heat means more air conditioning and more electricity consumed, leading to blackouts and, of course, more carbon emitted into the atmosphere. 

The heat island effect has been understood for a long time – I first learned about it in high school.  But more recent scientific knowledge indicates that we should expect more extreme heat waves like those this summer.  I’ve argued in this column and elsewhere (see our in-depth report, The Future of Home Improvement, here: www.williamverde.com), that dealers and distributors have an obligation to learn to anticipate changing climate and weather patterns in order to serve their communities, as well as boost their revenue.  In fact, as purveyors of building supplies, we are in a prime position to take the lead on mitigating the effects of hot summer nights and urban heat islands.

There are a variety of ways we can make our cities cooler, simply and affordably.  Replacing high thermal mass materials with trees and green space is one effective strategy and where we need to go, long term.  Living roofs are being boosted in major cities for just this reason.  But there’s another strategy that can deliver results in the short term, is less expensive, and offers opportunities for most dealers and distributors right now. 

Increasing albedo, or the ability of surfaces to reflect solar radiation, using special paints and coatings, or reflective roofing materials can dramatically reduce heat gain and electricity demand.  A white roof, for example, can reflect almost 90% of the sun’s radiation, reducing interior heat and the need for air conditioning.  And the savings are not trivial.  The White Roof Project (www.whiteroofproject.com) reports that about 10% of electricity produced by cities is used to compensate for the urban heat island effect.  If enough roofs were painted white, the nation could be saving billions of dollars and hundreds of lives.  And dealers could be doing well, while doing good.

Two excellent resources to help you stock appropriate roof coatings for your community, or improve your existing product mix, are Energy Star (www.energystar.gov) and Cool Roof Rating Council (www.coolroofs.org).  Keep in mind, reflective shingles and roofing tiles offer effective solutions for residential applications, too.  But don’t stop there.  Develop a promotional strategy that combines in-store materials with larger-scale efforts in the community.  In-store signage should educate customers, highlight rebate opportunities, and promote city-wide campaigns.  Get involved and get your manufacturers involved.  New York area dealers might ally themselves with the White Roof Project, for example.  Dealers in other sizzling cities might think about creating their own “white roof projects” in conjunction with local city agencies or non-profit organizations.  Last but not least, teach your staff about the urban heat island effect and the importance of taking measures to reduce it.  It can literally save lives.