4) Decrease Lighting NeedsEnergy savings from metal roofing also extending to lighting. Skylights and other roof-installed devices can strongly contribute to daylighting. One study found that an economically optimum toplighting system (defined as using skylights with electronic lighting controls to turn off electric lights when not needed) saved 35-55% of annual lighting energy, with smaller impacts on heating and cooling energy. The same study determined that toplighting could save 11-32 cents per square foot per year, depending on climate and building type.[iii]
The latest daylighting devices have marked advantages over traditional flat skylights. These domed units have prismatic embossing that collects up to three times more of the sun’s rays earlier and later in the day, when the sun angle is low. Prisms refract sunlight into microbeams that transmit more light into the building, without glare, hot spots or UV damage. The devices have been shown to reduce electric lighting costs by up to 70% when integrated with lighting controls, providing a return on investment in as little as three to five years.
The units can reduce the number of total roof penetrations by 30% due to their higher light transmittance. A self-curbing design avoids the inherent risk of leaks around flashings found in the traditional curbs used on conventional skylights. The system is integrated into the metal panel seams to minimize the amount of contact with water flow overall.
5) Add SustainabilityRenewable energy plays a growing role in buildings, and the potential for rooftop renewables is great. The National Renewable Energy Laboratory in Colorado has estimated that some 67 percent of the nation’s commercial buildings have rooftops available for solar water heating.[iv] Whether for thermal energy or electricity, quality metal roofs accommodate solar panels without requiring penetrations that could compromise roof integrity.
Steel roofing is also 100% recyclable, and the steel in a new or retrofit roof will contain 25-28% recycled content. Conventional roofing materials, on the other hand, are frequently disposed of in landfills and sometimes classified as hazardous waste.