In the vast, sun-drenched landscapes of Australia, where the sun blazes down with an intensity that can only be described as fierce, the colour of your roof does more than just complement your home's exterior.
... it's a critical factor that affects your indoor climate and energy expenditure.
Recent research in Australia has highlighted the significant differences in heat absorption between dark and light-coloured roofs, prompting a reevaluation of colour choices by homeowners and builders.
This article explores these findings and how they align with the innovative Colorbond steel colour range, steering you toward a choice that's as cool as it is savvy.
Plus, we also uncover the coolest COLORBOND® roofing colour - click to here to see the winner!
The Commonwealth Scientific and Industrial Research Organisation (CSIRO) has quantified a suspicion long held by many Australians: the colour of your roof is a major determinant of your home's heat retention.
Dark roofs absorb more heat, elevating the temperature of the structure beneath and exacerbating the urban heat island effect, which can see urban zones registering temperatures up to 4°C higher than surrounding rural areas.
COLORBOND® steel, a quintessential element of Australian roofing, presents a colour palette that's not merely varied but thoughtfully designed with Australia's unique climate in mind.
From the reflective 'Surfmist' to the understated 'Jasper,' each colour in the Colorbond range is engineered for thermal control.
The temperature difference between a roof in 'Night Sky' and one in 'Shale Grey' can be as contrasting as their names suggest.
Darker colours like 'Monument' and 'Deep Ocean' may be visually striking, but they also absorb more solar radiation, potentially leading to higher air conditioning expenses.
Conversely, lighter shades such as 'Dover White', 'Surfmist,' 'Pale Eucalypt,' and 'Classic Cream' are proven to reflect more sunlight, thus maintaining a cooler and more comfortable home interior.
Colorbond doesn't leave temperature control to chance.
Their Thermatech® technology is specifically formulated to reflect the sun's heat, even on the hottest days, ensuring that even the darker shades in the Colorbond range offer some level of thermal forgiveness.
Opting for a cooler metal roof colour transcends personal comfort. It's a choice that influences your energy bills, your ecological footprint, and the broader climate.
A lighter-coloured, energy-efficient roof doesn't just offer cost savings—it also contributes to a cooler, more sustainable environment..
Architectural scientist Mahsan Sadeghi from the CSIRO's energy business unit says
"The prevalence of dark construction materials has a substantial impact on the ambient temperature within these urban environments"
Under the Australian sun, a dark roof can reach temperatures up to 90°C, while a lighter roof may only reach 50°C on the same day.
This significant temperature difference has real-world implications for the comfort of your living space and the demand on your cooling systems.
Colorbond's selection is not just about looks; it's about combating heat.
The lighter shades in their lineup are particularly well-suited to Australian homes, reflecting the sun's rays and promoting a cooler roof surface.
Here's a glimpse at some of the standout colours:
- Dover White™ (New): Inspired by the chalky sands, glistening ghost gum bark and pristine alpine snow. Clean, crisp and timeless.
- Surfmist®: Emulating the bright, reflective properties of sea foam, this color is perfect for those seeking to maximize the reflective benefits of their roofing.
- Dune®: Offering a soft, neutral tone that harmonizes with the Australian terrain, it strikes a balance between warmth and coolness.
- Evening Haze®: A light, warm grey that delivers a modern aesthetic while still reflecting a significant amount of solar radiation.
The Dover White™ Colorbond colour stands out as the coolest metal roofing option in Australia.
With its specific Solar Absorptance (SA) value of 0.28, which ensures minimal heat absorption, and an impressive Solar Reflectance Index (SRI) of 88, maximizing the reflection of the sun's rays.
Solar Absorptance (SA) ranges from 0 (no absorption) to 1 (full absorption), with Solar Reflectance (SR) being its inverse for opaque materials.
The Solar Reflectance Index (SRI) compares roof 'coolness', from a 'hot' black (SRI=0) to a 'cool' white surface (SRI=100).
|Solar Absorptance (SA)
|Solar Reflectance Index (SRI)
The provided solar absorptance values (SA), representative of new products, have been measured in accordance with ASTM E 903-96, focusing on thermal properties rather than visual impact.
For a detailed understanding, refer to BlueScope Technical Bulletin TB 39 on the thermal performance of roofing materials.
For the full technical explaination of SA & SRI Thermal Ratings - click here
While lighter shades are designed to reflect sunlight, darker shades absorb it.
A cool white metal roof amongst a sea of hot dark roofs
Colours like 'Monument' and 'Night Sky' are deep and bold, but they also transform more of the sun's energy into heat, which can seep into your home and increase your energy consumption.
However, with adequate insulation and ventilation, the impact of these darker colours can be lessened.
Colorbond's Thermatech® technology is a game-changer, particularly for those who favor a darker palette. This technology is crafted to enhance the solar reflectance of even the darkest colors.
For instance, a colour like 'Woodland Grey', while naturally absorbent, is engineered to be more reflective than a standard dark roof, courtesy of Thermatech®.
A cool roof colour is merely one aspect of a thermally efficient home. Adequate insulation, ventilation, and shading collaborate with your roof to maintain a comfortable indoor climate.
Colorbond roofs are compatible with various insulation materials and designs, ensuring that the colour you choose is bolstered by an effective thermal system.
Selecting a cooler roof colour is a stride toward diminishing your environmental impact. Lighter roofs help lower energy consumption, reduce greenhouse gas emissions, and alleviate the urban heat island effect.
By choosing a Colorbond colour that reflects more sunlight, you're joining a larger movement toward sustainability.
When picking your Colorbond roof colour, take into account the following:
- Local Climate: The intensity and frequency of sunlight your home is exposed to.
- Architectural Style: The desired aesthetic and how it complements your home's architecture.
- Energy Costs: The potential savings on cooling during the warmer months.
- Resale Value: The attractiveness of your home to future buyers with an energy-efficient roofing solution.
Ultimately, the coolest metal roof colour is one that matches your taste, suits the Australian climate, and fulfills the requirements of energy efficiency.
With Colorbond's spectrum of colours and cutting-edge Thermatech® technology, Australian homeowners are well-equipped to make a selection that is visually pleasing, thermally comfortable, and environmentally considerate.
Whether you choose the reflective prowess of 'Surfmist' or the subdued elegance of 'Jasper', you can be confident that your Colorbond roof is designed to keep you, and your home, comfortably cool.