The roof of your new build is one of your biggest weapons when it comes to tackling energy prices and keeping a steady temperature indoors. Energy efficiency is an incredibly popular topic – and for good reason. The more energy-efficient an appliance, HVAC system, or roof is, the more money you can potentially save in energy.
But being energy efficient doesn’t just mean looking for low energy rating stickers and efficient LED lightbulbs – it can also start with the development of your house. Explore everything you need to know about energy-efficient roofing materials and why they matter below.
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What are the requirements for energy efficiency in Australia?
The National Construction Code (NCC) has recently been updated with some major changes surrounding energy efficiency, stating that new houses and units must now achieve a 7-star energy equivalence rating out of 10 for the building shell. This includes the walls, windows, floors, and roof, which means the material you use for the roof just got all the more important! Choosing an energy-efficient roof is a quick and often low-cost way of boosting your new build’s star rating.
Learn more about the NCC energy efficiency requirements for homes.
Why do roofing materials matter?
The roof is one of the largest components of your house exterior, meaning if it’s not made from efficient materials, there’s an incredibly large amount of space where heat can escape from – causing your heating bills to rise. Likewise, if a roof is made from a material that lets a lot of heat to energy from the sun in, you likely find that your AC bills skyrocket.
Choosing the correct material for your roof can save you or the homeowner plenty of money. If you’re planning on selling your new build, an energy-efficient roof also drives the market value up and hopefully generates more interest so you can have an easier time selling it.
What makes a roof energy-efficient?
The idea of using an energy-efficient roof is certainly appealing to most developers, but how do you know what constitutes energy efficiency?
Rooftop temperatures can reach between 30 and 40°C hotter than the air outside. When your roof is dark or prone to heat absorption, this heat can be sucked into the attic and then your living Spaces.
Most roofs come with good insulation which offers relief to some extent, but the difference between a normal roof and an energy-efficient alternative is incredible. While good insulation can help, it’s not going to stop the heat from being transferred from the roof into the attic – which will undoubtedly make your AC system work harder than it needs to.
There are two many factors to look for to make a roof energy-efficient:
Solar reflectance index (SRI)
The SRI measures the roof’s ability to reject solar heat and release any heat that gets absorbed. The higher the SRI on your chosen roof, the better. Raising the SRI from 25 to 40 can lower the roof’s surface temperature by more than 13 degrees! This could save you between 15 and 20% on your energy bill.
Solar reflectance might not seem as important in cooler climates, which don’t get as much sun, but in Australia, where temperatures can reach up to 50 degrees, it can make all the difference in summers. If you find yourself reaching for your AC unit a lot, an energy-efficient roof should be able to help you turn the temperature up by a few degrees.
Ventilation
Another factor that’s going to come in handy for energy-efficient roofs is ventilation. Good ventilation keeps any heat that’s transferred from the roof into the attic building up and reaching insurmountable temperatures. Even if your attic does absorb more of the heat from outside, at least it has somewhere to go with a proper ventilation system. Without this, there’s a higher likelihood that the heat would be lowered in your living areas to raise your prices.
The three main types of roof vents used in residential roofing are static vents, wind-powered venues, and eclectic vents. The type of vent you choose, along with how many you’ll need, will depend on how much ventilation your new build requires.
What are the different types of energy-efficient roofing materials?
It might come as a surprise that plenty of roofing materials have actually been rated as energy-efficient. However, there are definitive differences from one type to another, so let’s dive into everything you need to know:
Metal roofs
Metal roofing is one of the best choices for residential new builds in general. Thanks to its reflective nature, it’s the most energy-efficient roof material and can last over 50 years, making it excellent value for money.
You might be thinking that if metal is a conductor of heat, then surely it absorbs more heat than it’s worth to be efficient. While this is true and metal roofs do often get hot to touch, the majority of the sun’s energy ends up coming straight back off the roof and into the fresh air. This means their SRI rating will be surprisingly high.
Plus, metal roofs can be covered with reflective coating to give them an even higher rating, so they really are one of the best energy-efficient options.
Tile roofing
Tile roofing is another good choice that’s also energy-efficient. These are often made from clay, concrete, or slate, and they can be pre-treated to maximise how much heat reflects off of them throughout the day. In fact, these treatments can even be installed after the tiles are put on the roof, so it’s never too late to maximise their energy efficiency!
Tile roofs are also excellent for absorbing air and allowing it to flow beneath the tiles, which adds to their ventilation. This means that any heat that does get absorbed easily has a place to go other than down into your living areas.
Asphalt shingles
Asphalt shingles are one of the most common types of roofing material used on homes, and they’re traditionally one of the most non-reflective and heat-absorbent options available.
You might be wondering why we’re introducing them to you if that’s the case. Fortunately, the development of asphalt shingles has come on leaps and bounds in recent years, making them more efficient than ever before. New asphalt shingles are being made with solar reflecting granules to raise SRI and even make the roof’s lifespan longer by reducing its surface temperatures.
Bear in mind that many asphalt shingles still don’t have this technology, so you have to go searching if this is the material you want to go for. Without the solar reflecting granules, asphalt can reach temperatures of up to 40 degrees C hotter. So if you want to use this material, make sure you find a trusted supplier.
How much do energy-efficient roof materials cost?
On average, metal roofs can range from $50 to $180 per square metre for materials and installation. Asphalt shingles are slightly cheaper at $35 to $80 per square metre, but bear in mind that the reflective granules will likely raise this price. Depending on which type of tile you use, they can range from $40 to $140 per square metre.
Energy-efficient roofing will almost always cost more – but the benefit is that they usually pay for themselves over time in reduced energy costs. Homeowners will often pay more for an energy-efficient roof as it means fewer running costs, so for developers, we believe the choice between normal roofs and energy-efficient roofing is a no-brainer.
What are the advantages of energy-efficient roofing?
There are plenty of benefits to installing an energy-efficient roof, such as:
Saves the homeowner money
Homeowners will experience fewer energy spikes during hot and cold seasons because the roofing material should keep indoor heat in and outdoor heat out. This means they should be able to utilise their AC and heating units less, saving them plenty of money in the long run.
Developers can boost their property value
If you’re building to sell, making a big deal of the energy-efficient roof is a huge selling point. People will be more likely to pay for a feature that’ll save them more money in the long run, so you can increase the asking price and potentially make a bigger profit.
Extends the roof’s lifespan
Most roofs will last between 20 and 50 years with good upkeep, but energy-efficient materials can live even longer. This is because the materials have to deal with less absorbed heat as it’s reflected away instead, so they don’t have to withstand such intense pressure. Again, this is a great selling point to give to prospective buyers!
Boosts the longevity of AC and heating systems
When you have to use your AC unit and heating system less, they should last longer – that’s simple mathematics. These systems aren’t cheap to replace either, making this another way the roof can save homeowners money over time. Depending on how great the roof is at keeping heat out, an AC unit might not even be needed!
Can prevent power outages
An energy-efficient roof can help prevent power outages by lowering peak electricity demand, keeping homeowners more comfortable and happier with their homes. Fewer power outages also remove such a need for backup power storage systems, which can save money and take the stress away from owners.
Are there any disadvantages to energy efficient roof roofing materials?
It might be hard to believe, but there are some factors about energy-efficient roofing that could be considered drawbacks. Here are some you might need to consider:
More expensive upfront
While it’s a great benefit that energy-efficient roofing can save money for homeowners, it’s still going to cost you more upfront than a normal roof. If you have a budget allotted for your development, a more expensive roof might not fit within these parameters. This is especially true if the new build is particularly big or with an extra roof allowance, as you’ll most likely need to pay per square metre.
Less range to choose from
While you can choose from a range of roof materials that come in various colours for energy efficiency, you’re still going to have less range than if you were to use a normal roof. For example, copper, concrete, and normal asphalt shingles are all great options for normal roofs, but they’re not going to work any wonders in terms of energy efficiency.
Explore NCC requirements and regulations that you need to know for a new build
- NCC changes 2024
- NCC energy efficiency requirements
- NCC waterproofing requirements
- NCC floor waste requirements class 1
- NCC handrail requirements
- NCC disability access requirements
Get free advice on your new roof from an experienced building broker
If you’re still unsure about energy efficiency and roofing materials, Buildi’s team of experts are waiting for you to get in touch so we can offer you free advice! Why not get in touch at 1300 947 132 or through our Contact Form to see how we can help today?
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