The Truth About White Roofs and Climate Change

Building materials affect how resilient your home is to climate change. Besides their composition, how does color come into play? Research has demonstrated interesting results for white roofs. Some say they can combat the effects of global warming in the coming years. 

Here’s the truth about white roofs and their impact on the environment. 

How Do White Roofs Connect to Climate Change?

Your roof is just one small part of your home, so how does it relate to the global fight against warming temperatures? Consider where the weather impacts your home the most. When it rains or the sun shines, your roof benefits or pays the price, depending on the circumstances. In the summer, your roof absorbs sunlight and transfers the heat to your interior. Therefore, your utility bills could increase with heat waves. 

Now, consider which colors reflect and absorb the best. If you wear white clothes, you can stay a little cooler. Conversely, dark clothing makes you feel warmer because it feels hotter to the touch. Some experts say white roofs can reduce the impact of climate change by reflecting light instead of letting it into the house. After all, experts say surface temperatures have risen by 0.11 degrees Fahrenheit since 1850. 

White Roofs Benefits

So, could a white roof help your home and the environment? Here are # reasons why you should consider one for your building. 

1. Reducing Solar Gain

The primary goal of white roofs is to reduce solar gain. For sub-tropical and tropical climates, this change could save lives by lowering interior temperatures and reducing the risk of heat stroke. Imagine if you live in Miami during the summer and your air conditioner breaks. If you don’t take prompt action, you risk fatal consequences for you and your loved ones. Fortunately, white roofs could mitigate the issue. 

The University of New South Wales, Sydney, has researched the benefits of cool roofs compared to darker structures. Through their analyses, the experts found positive results in urban areas like Sydney, Melbourne and Adelaide. These white roofs decreased temperatures by 4 degrees Celsius, thus reducing temperatures above 26 degrees Celsius by 100 hours in the summer. How’s that for a proper cooldown? 

2. Low Price Tags

When considering these significant changes, you must compare the costs of each roof. After all, the cost of living in America increases annually. Luckily, white roofs are cost-effective compared to dark and green roofs. Affordability is a chief concern, especially in areas with lower incomes. Climate change affects those from the equator to each pole, so ensuring cost viability over the years is critical. 

While green roofs are great, they can become more expensive regarding maintenance. Excessive organic matter and roof drains require your attention, or the rooftop could do more harm than good. Also, you must have a proper irrigation system or supply the water yourself. If not, the green roof concept could be a waste of time. White roofs require less maintenance and fit economic needs.  

3. Limiting the Heat Island Effect

While white roofs can impact climate change anywhere, their effectiveness is most pronounced in urban areas. Dense cities are often more vulnerable to global warming if their buildings are close together without green spaces to absorb the heat. Thus, implementing these lighter-colored roofs could significantly benefit a large city by reducing the sun’s impact. One European city has already considered implementation en masse. 

Scientists at the Autonomous University of Barcelona (UAB) said widespread white roofs could reduce temperatures by 4.7 C during heatwaves, depending on the time and location. The researchers found existing building materials make the city’s infrastructure retain solar radiation, thus increasing temperatures. With this low-cost strategy, Mediterranean cities like Barcelona could safeguard themselves from climate change. 

White Roof Disadvantages

While white roofs can be conducive, their disadvantages are worth considering. Here are a few reasons why they might not be the best answer for climate change defense. 

1. Location-Specific Benefits

While the climate is warming, some places still get extremely cold. In fact, this phenomenon could lead to more extreme weather events. Experts say the planet could see more serious winter storms as the years pass. If you have a white roof in the winter, you might not get much help. You may need a darker roof to absorb the minimal sunlight during the cold months and increase heat. 

Therefore, the benefits of your white roof may only extend to warmer areas. If you live in the U.S., Mexico or other subtropical climates, this color makes sense for your rooftop. However, imagine how residents of Iceland and Norway may feel in the wintertime with a white roof. Even the summers here can be mild at best, so a dark roof could be the best option despite the planetary changes.  

2. Green Roof Comparisons

The debate is intense between green and white roofs. After all, both can significantly help homes in urban and rural areas defend against the heat. That said, it’s worth examining which one performs best. The answer depends on what you’re looking for, as homeowners may differ on priorities. A white roof may excel with cost-effectiveness, considering its low prices. However, green roofs have notable benefits. 

One of the best advantages of your white roof is the improved U-value — the metric determining how well a material insulates the building. A 2021 Indoor and Built Environment study found green roofs enhanced U-value by 28% and reduced solar heat gain by 76%. Therefore, indoor air temperature decreased by 2.5 C. While white roofs performed well, they didn’t compare to the green ones. 

3. Increased Maintenance Needs

Remember what your mom told you about wearing white clothes? If you put them on, you better be careful when eating or going out in bad weather. Dirt and debris could quickly ruin your outfit and make you return home for a change of clothes. Similar logic applies to white roofs, considering how many factors could affect their coloring. Just imagine bird poop or dirty snow falling from the tree onto your rooftop. 

The maintenance of white roofs could ultimately be counterproductive for combating climate change. More frequent washes mean you use more water to eliminate the dirt and unwanted debris. Therefore, you consume natural resources and strain municipal services more than necessary. If these roofs become widespread, you could see an exacerbated impact during water shortages. With more frequent droughts, they could be a disadvantage.    

Examining White Roofs for the Future

Solving the climate crisis involves using widespread solutions regardless of their size. What’s a small change that can impact your carbon footprint? Painting your roof white could be one of the most straightforward strategies for reducing heat islands and improving interior comfort. These roofs should be considered, especially if you live in a warmer climate.