Published: July 1, 2018

Black or White roof? What’s the best roof for your facility? What’s the best color? These questions have brought up many different opinions as well as several surveys that seem to support almost any roof or color you want. This article will just cover the roof color: black or white.

Whether you’re renovating or building new, the roof always comes up and in many cases it’s quickly chosen based on cost or what the trend is. Your decision should not only be on aesthetics, but on relevant research, energy efficiency and material availability.

ENERGY EFFICIENCY: COOL ROOFS VS. WARM ROOFS

Roof color can have a major impact on your electricity bill. In the past, it has been argued that white roofs are more energy efficient than black roofs, thus making white roofs the best color for all types of buildings.

White roofs are known as “cool roofs” because white reflects sunlight, keeping most of its heat away from the building. Black roofs are known as “warm roofs” because they reflect less sunlight, allowing more of the heat to build up on the roof. The difference is significant: on a hot day, a black roof can be 100 degrees warmer than the air temperature, while a white roof will only be 20 degrees warmer. During the hottest months of the year, a white roof can significantly decrease your energy usage. Many of the studies we have read stop there and claim white is better. But is it?

ARE COOL ROOFS ALWAYS MORE COST EFFECTIVE?

The early roof studies concluded that white was objectively the best roof color for cost effectiveness. Most of these studies were conducted on buildings that were in the southern states. Later, studies showed that in cooler, northern climates, white roofs can still result in higher annual energy costs for facility owners.

This is because in the winter months, buildings with white roofs will reflect the warmth of the sun and result in higher heating costs than buildings with black roofs. The decreased cooling costs will be offset by the increased heating costs. As a result, in northern areas, black roofs or “warm roofs” are the best roof color for cost effectiveness and environmental friendliness. In the south and on the West Coast, cool roofs are the better option.

In the past several years, the cost of white roofs have come in lower than black roofs. To many owners, the cost of the material and installation are the major decision factors to the overall performance or cost savings.

We at FMC Architects will always try to give the best possible solutions to our clients, but in the end we use what they believe is the best for their building and location. Give us a call, we will be happy to go over your building roof choices.