What are Cool Roofs & Do I Need One?

Tips & Advice
technician installing cooling system

In a growingly environmentally conscious world, homeowners everywhere are looking for ways to be more proactive in helping to cut down on carbon emissions. Not only this but with our warming climate, everyone is looking for ways to cool down the house. The problem, however, is that many of the methods we use to cool our homes are actually damaging the climate at the same time. Electric fans, swimming pools, and particularly air conditioning systems all add up to your overall carbon footprint.

However, one of the more recent inventions that have been growing in popularity in other parts of the world is cool roofs, and with our summer months getting increasingly warm and humid, many homeowners in the UK are now actively looking into applying this system to their roofs.

But do you really need a cool roof? Well, as you’ll find out in this guide, cool roofs aren’t as drastic a change to our normal roofs as they may sound. We’ll look at what cool roofs actually do, the benefits and drawbacks, and whether or not they’re really necessary not just for your home, but for the environment as a whole.


What is a Cool Roof?

Let’s start with the basics – a cool roof is a specialised roof that is designed to reflect more sunlight than the average roof. This means that it absorbs less solar energy, and thus lowers the temperature of the building.

There are actually multiple different sub-types of cool roofs, but all of them are designed to achieve this one purpose – to reflect sunlight and cool your home. On extremely hot days, non-cool roofs can reach up to 65°C, and much of this heat is transferred directly into your home.

Many homeowners believe that the reason the upper floors of their house are so warm in summer is because heat rises, meaning all heat from the floors below eventually ends up in the bedrooms and loft. This is true, but the situation is exacerbated considerably by the heat coming in from non-cool roofs.

There are many benefits to cool roofs, therefore, both practically and financially. As we’ll explore later, there is also evidence to suggest that it helps conserve the climate too. Most cool roof systems boast thermal emittance features – in short, this means they possess the ability to shed heat by giving off ‘thermal infrared’ radiation. Below we will look at some of these benefits, and others, in greater detail.

What are the Benefits of Cool Roofs?

There are many ways a cool roof can benefit a home or community building. One of the biggest is that it can eliminate the need for an air conditioner. As the summers get undeniably warmer each year, there is a growing trend amongst UK homeowners to buy air conditioners.

These are already extremely popular across America, but they consume a lot of energy and are bad for the environment, contributing to warming the world while cooling the home. Cool roofs can cool the home so much, that the need for an air conditioner disappears.

Your home will also be generally more comfortable, both upstairs and downstairs, as there is less heat being transmitted around your home. By decreasing the temperature of your roof, its lifespan may be increased, with the various components less likely to warp under these cooler temperatures.

In certain urban environments, cool roofs can actually contribute to lowering outside air temperatures, lessening what is known as the urban heat island effect, where clusters of urban housing with many heated roofs contribute to the overall warmer temperatures in urbanised areas.

With cool roofs making houses less warm, there is less of a desire for various cooling electricals such as fans as well as the aforementioned air conditioners. This can help to decrease the electricity demand, which can help organisations save and conserve additional electricity.

Indirectly, cool roofs can therefore contribute to less power plant emissions by reducing power demand. Finally, by reflecting sunlight away from the planet, cool roofs are arguably positively contributing to the fight against climate change.

Are There Drawbacks to Cool Roofs?

There are only two stark drawbacks to cool roofs. The first is the price which, as we’ll delve into further below, can start to rise considerably based on certain circumstances such as the age of your roof. The cost mainly comes from the conversion process, which can take a lot more tools and equipment to carry out if already-existing components are incompatible.

The other drawback is the fact that cool roofs will not absorb sunlight at any time of year, including the winter. While this doesn’t tend to have much of an effect on the temperature of the home overall due to the predominantly wet and overcast weather in winter, it must be noted that your home may still become a little colder. This may increase your dependence on artificial heating.

However, the difference shouldn’t be too extreme, unlike the difference in temperatures when a cool roof is performing well in the summer months.

Does a Cool Roof Cost More Than a Non-Cool Roof?

When it comes to initial installation, a cool roof does not cost more than a non-cool roof in most cases. This is true whether you are installing a brand-new roof or instead replacing an existing one. The prices start to rise when you attempt to convert an already-existing roof that is actually in good condition. This is because removing and replacing the different components of a good roof will be expensive, while you are also still having to pay full price to install an entirely new roof.

When deciding whether or not a cool roof is financially viable, consider the benefits mentioned above. How much do they apply to you? If you don’t find yourself struggling in the heat when the summer rolls around, then maybe a cool roof isn’t for you. However, if you find summer’s increasingly uncomfortable, and spend a lot of money on electricity when keeping your home warm, a cool roof may be the ideal solution.

If you are constructing a new home, a cool roof may well be worth the investment. Several types of roofs aren’t cool roofs but can be fairly easily and cheaply converted. If you are curious as to whether or not your roof could be easily converted, consult an expert on the matter.

There are many tradespeople out there who are now familiar with this relatively recent concept, and it may be worth getting in touch to see if they can offer you any advice or even a quote.

Does the Climate Matter in Regard to a Cool Roof?

Your local climate will absolutely influence the effectiveness of a cool roof, and you’ll need to consider your location when it comes to deciding whether or not a cool roof is for you. When it comes to the UK, cool roofs will offer the best performances in southern areas of the country where it tends to be hotter. Cities are also much warmer than rural areas, meaning that the ideal area for your cool roof will be locations like London, Kent, Devon, and Bournemouth.

Meanwhile, houses in the Scottish highlands or the rural midlands/north are less likely to see the benefits of cool roofs at this point in time, although there are exceptions. Houses with little or outdated ventilation systems, semi-detached and terraced homes and larger buildings are all examples of homes that may benefit from cool roofs. Not only this but as the climate changes, your roof will undoubtedly become a more valuable asset to your home, as we’ll explore next.

Is Climate Change Making Cool Roofs More Important?

Climate change is making cool roofs more necessary year after year. No matter where you are in the world, temperatures are rising considerably, and while that means an increase in everything from storms to showers, it also means that periods of heat are longer and more intense. Despite the efforts of multiple countries, the world continues to heat up, and it seems like it will continue to do so for the foreseeable future.

While the UK is better equipped to deal with this change than many other countries, to say things will get more challenging for the country is a huge understatement, as powerful heatwaves with the potential to injure or even kill more vulnerable members of the population will become more commonplace. Another challenge the UK faces is that winters will continue to be cold and wet, meaning that we as a nation will need to start creating houses that can protect us in all weather.

This is why cool roofs are important, and why the majority of builders and tradespeople should consider utilising them in future projects. They are by no means going to be the sole solution to the increasing heat problems the country faces, but they will go far in combating the most severe effects, especially in urban locations.

It’s safe to say cool roofs are game changers when it comes to protecting your home against the hotter weather we are now destined to experience, but are we at a point where they are necessary?

The short answer is no, in part because of how they may affect your home in the winter. However, the best houses in the future will be those that are made ready for both cold and hot months, with adequate insulation coupled with heat-combating technology such as cool roofs.

So, if you’re looking to construct a new roof, or your old roof needs rejuvenation, consider a cool roof, and help do your bit to not only cope with the warming climate but also to combat it.

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