Energy-Efficient Home: Which type of Home is more energy-efficient?
Our focus here at Hensley Park Homes is on crafting your place in the country, and as a result our homes are traditionally weatherboard, with a suspended floor to better accommodate the verandah and deck.
And we’ve come across the question a few times as to whether a brick and slab construction is a more energy-efficient home. We like to be open and honest, so this article is to drill into this question for the benefit of all.
Firstly, we want to address the format of the question. Asking if a brick and slab home is a more energy-efficient home is a bit like asking which is heavier, a tonne of rocks or a tonne of feathers. They both weigh a tonne! Perhaps a better way to put the question is whether it’s easier to achieve a 6-star energy rating with brick and slab than weatherboard and steel.
Ok, so onto the answer. And unfortunately it’s a bit complicated.
Step one is to understand how a house is rated for energy efficiency. We’ve actually got another piece on that, but here’s a quick overview. It’s all about how the home makes use of the energy from the sun. When the sun shines onto the home, how much of it gets inside? And how much of the warmth from the sun is retained? And how easily does the home let the warmth go?
The answers aren’t necessarily good or bad, because it depends on the climate and orientation of the home, and the weather each day. If it’s freezing, then you want as much warmth as you can get and to retain it. But if you’re sweltering in the Aussie summer, then you want that warmth to disappear as quickly as possible as the day wears on.
And then the next thing is the design and features of the home. How big are the windows? Are there verandahs and other shading elements? How high are the ceilings? Where are the ‘habitable’ rooms located? Can a breeze flow through the home from north to south?
Finally it comes down to the products that the home is made of. What’s the cladding? How much insulation is included? What is the floor made of? And it’s at this point we can address the question as to which is better – brick and slab or weatherboard and steel.
In isolation, brick has a higher thermal rating, which means that it retains more heat for longer than weatherboard. And the same goes for a concrete slab vs a suspended steel floor.
But in the final wash-up, it’s been proven that it has a negligible impact on the efficiency of the way the home uses the sun. And this is mostly for 2 reasons.
The first one is because if the home is designed so that it grabs the sun in the best possible way, and the windows are the right size to let it in, and double glazed to ensure no warmth leak, then as the sun hits the north wall of the home, and a bit of the east and the west walls, then you might save a bit of money in winter due to that little bit of extra thermal capacity that the brick and slab has, but in reality that saving might be 10 to 20 cents a year, and you’ll probably lose it in the summer when you don’t want the warmth retained.
The other reason is the products themselves and how they’re used in the home. Both the brick and the weatherboard are facade or cladding material only. Neither of them are used as insulation – air is the best form of insulation and both styles have plenty of insulation. And a suspended steel floor has a special type of insulation whereas a slab has none.
So when the rater calculates the efficiency of your home, they take everything into consideration, and both weatherboard and brick homes come out comfortably over 6 stars if the home is designed effectively.
We know of many brick and slab homes that are not energy-efficient homes due to the way they’ve been designed and built, and vice versa, we know of plenty of weatherboard homes that have hit some serious energy efficiency levels due to superior design.
Every home has to achieve a 6-star rating to get building approval, and there are many homes built all the time in both styles with the occupants living comfortably in them.
So which type of construction is a more energy-efficient home?
Neither. It’s good design that really matters.
Keen to find out more?
Reach out to us. We’re here to help.