Ever since man first began building his own structures, a roof has meant more than just protection from the rain. It’s meant survival. Although humans have not always considered the importance of energy efficiency in the same way throughout the ages, energy has always been a key component to structural design. The roof has played no small part in this. A solidly build roof helped many cultures keep in heat, ensuring survival during the sometimes long winter months. Alternatively, some roof designs helped regulate temperatures, and even kept the interior cooler(pdf) during hot days.
Now, energy efficiency is more a matter of cost savings and environmental impact. There are a large number of energy efficient roofing options. Some are as new as possible. Others are simply a modern take on tried-and-true building practices from cultures across the world. All have been proven effective at save energy, lowering costs and making homes all the more attractive. John Anderson, of Severe Weather Roofing and Restoration in Loveland, CO suggests two options below.
1. White (Reflective) Roofing
Heat science is very well understood. At the most basic level is this: Of all colors, black absorbs the most heat, while white reflects the most heat. The difference can easily be recognized in experiments conducted using cars painted white, silver and black. There, it was discovered that black cars were, on average, around 9-11 degrees (F) hotter than their white and silver counterparts.
This same principle has been applied to roofing as well. Many people have recognized the vast temperature differences and energy efficiency benefits related to lighter-colored roofing. White in particular has been recognized as the most energy efficient roofing color. White roofing will reflect around 90% of the sun’s radiation, leading directly to lower energy costs due to cooler inside temperatures. The numbers are significant. White roofing has been shown to bring down energy costs as much as 40%.
There are certainly drawbacks to white roofing. Although the movement has caught on across the country, white roofing is only cost effective in areas with warmer climates and more sun. Individuals considering white roofing should remember that the reflective principle of colors applies all year. White roofing will reflect heat in both the summer and the winter. This is potentially bad news for those in more northern climates, where white roofing could result in a net gain in energy usage and cost.
2. Consider Metal Roofing
The black asphalt shingle has been an American staple since the early 1900s. However, this is an American classic that has resulted in a significant amount of energy inefficiency. Black asphalt shingles absorb a massive amount of heat, requiring the use of air conditioning and wasted energy. Metal is a great alternative for saving money — in the long run.
Metal roofs have been shown to reflect 40-50% of the sun’s energy back outward, radiating that heat away from the building underneath. This ultimately leads to cooler temperatures and less energy demand for cooling. Much like white roofing, the effects are primarily found in warmer climates than cooler ones. The real downside to metal roofing is not the fact that it still reflects in the winter, however. It’s the cost. Metal roofs can cost three times as much as asphalt. However, they will also last three or four times longer.
Weigh Your Options Based on Climate
Ultimately, anyone looking to save energy through roofing options needs to consider their climate first. It’s easy to get caught up in the desire to save energy, bring costs down, and help the environment, only to find out later that your efforts were wasted and even had detrimental effects. When it comes to energy efficient roofing, climate is the biggest factor. Before diving into an energy efficient roof, make sure it’s the best course of action for your home.