10 Ways Good Design Can Keep Your House Cool In Summer
Over the last few months we have all seen the rise is energy costs. Senior Writer for Houzz Australia, Georgia Madden, spoke to the professionals to provide the top tips to addressing energy costs when designing your home, below.
With rising energy costs and another scorching summer on the way, now’s the time to think about design strategies to keep your home naturally cooler – and there’s no better opportunity than when you’re building or renovating.
“A house in a hot climate can be made comfortable by providing heaps of air movement and shading, making the home healthier to live in and better for the planet,” says Madeline Sewall, director of houses at Breathe Architecture. “Including good design principles will ensure your home is running efficiently, limiting its impact on the environment [by using less power], reducing your ongoing cost of living – and, of course, keeping you comfortable all year round.”
1. The Benefits Of Double-Glazed Windows
When it comes to unwanted heat gain, windows are one of the weakest spots in your home. So if you’re looking to reduce your reliance on cooling and heating, it pays to upgrade to more efficient, double-glazed window styles, says Sewall.
“According to the Australian Window Association (AWA), up to 40 percent of a home’s heating energy can be lost through windows and up to 87 percent of its heat is gained through them, making double glazing an important and worthwhile investment of any sustainable home,” she says.
“With updated BASIX (Building Sustainability Index) requirements [for Australian homes], the use of double glazing is becoming more common with more local suppliers providing for it. Double glazing offers greater levels of insulation for your windows and reduces the level of thermal transmission in and out of the building, making for a more efficient home,” says Andy Harding, architect and director at Stanic Harding.
2. Use Thermal Mass
Building with the right materials will help keep your home cooler without you having to lift a finger, says Sewall. “High-density materials, such as concrete, brick and rammed earth, have high thermal mass as they take a long time to heat up and cool down. In summer, thermal mass that is shaded from the sun cools down overnight and provides a cooling effect as air moves over it.
“Smart positioning and use of thermal mass can thereby act like a natural heating and cooling system, regulating temperature highs and lows to a comfortable median,” she says.
3. The Best Orientation For A House
If a temperate indoor climate is your goal, rather than orientating your house to optimise a view (however tempting), focus on sunlight instead, says Harding.
“Houses should be able to take advantage of the daylight available and, ideally, be able to capitalise on northern sunlight, which is higher in the sky and less penetrating compared to eastern (morning) and western (afternoon) sunlight.
“Generally, the western sun carries the greatest amount of heat, therefore it is important to control this entering the home. This control needs to be flexible as winter western sun is a blessing, especially in cooler climes,” he says.
4. Window Size
You may want to rethink those wide expanses of glazing if you want to keep your house naturally cooler.
“Getting window-to-wall ratios right has a huge impact on the thermal performance of [a home],” says Sewall. “Even double and triple glazing are thermal weak points in a building’s envelope, so it’s important to balance amenity with the amount of windows by framing key views and letting in favourable light, without using sweeping expanses of glass,” she says.
“We also think deeply about ensuring that we are positioning windows to allow in daylight while minimising heat gain and loss, for example by maximising northern light and using openings in other orientations strategically,” says Sewall.
6. Encourage Cross Ventilation & Stack Ventilation
“Windows and doors should also be positioned for cross- and stack-ventilation to encourage natural air movement through a house, which helps cool people and spaces, and lets built-up heat escape,” says Sewall. “With different paths of natural ventilation through a house, artificial air conditioning can be avoided. Fly-screening on windows also helps to ensure that natural ventilation can be used comfortably year-round.”
When planning for efficient cross- and stack-ventilation in your home, it’s important to take into account the prevailing winds in your location, adds Harding.
7. Choose High R-Value Insulation
According to the Australian government’s Yourhome website, you can reduce summer heat gain by up to 35 percent by adding insulation to your ceiling. Summer heat gain can also be reduced by up to 25 percent by insulating your walls, or by up to 20 percent through insulating your floors.
‘R-value’ refers to the absolute thermal resistance of an insulation barrier and measures each product’s ability to resist heat flow. The higher the R-value, the greater the level of insulation your home will have.
“Combining insulation with good-quality glazing will help create an effective thermal barrier between the inside and outside of your house. This will give you greater control over the internal temperature of the building,” says Sewall.
“Insulation is probably one of the most important and cost-effective measures to offer additional protection to a house,” says Harding. “It can convert houses from being open airy ‘tents’ into thermally more effective ‘eskies’.”
The right roof set-up and inclusions can help with natural cooling in other ways too, says Harding. “The use of lighter, well-insulated roofs make a huge difference to the heat build-up within a house. And adding solar panels doesn’t just provide for renewable power in your home, it can also create an air gap above the roof surface [which helps minimise heat gain inside your home].”
8. Use The Right Direction For Ceiling Fans In Summer
“Simple ceiling fans can reduce indoor temperatures by circulating air. They are the cheapest cooling option and have the lowest greenhouse impact,” says Sewall. “We always look for ceiling fans that have a winter mode so that heated air can be circulated effectively rather than getting trapped up at a high level. In Victoria [where Sewall’s practice is based] the use of sweep/ceiling fans, in combination with good passive design, is generally sufficient for cooling a house during summer.”
Most ceiling fans should spin anticlockwise in summer to push cool air down towards the floor, but it depends on your model and its blade design.
9. Shade Your Home
“Stopping the sun’s rays hitting the glass is essential to avoid heat build-up within the home,” says Harding. “This can be achieved with retractable external venetian blinds, fixed or operable louvres, and fixed or operable projecting awnings. The benefit of operable systems is that they can be removed or opened when not required for shading. However, they are slightly more expensive than fixed styles.”
Sewall agrees on the importance of shading. “In summer, precisely angled shading of walls and windows – through awnings or external blinds for example – will block the intense sun from entering the building, allowing the interior to remain cool and comfortable,” she says.
Considering adding screening to your home’s exterior? “As a general rule of thumb, protection against northern sunlight is best achieved with horizontal screening, while vertical screening is more appropriate for eastern and western sunlight,” says Harding.
10. Plant Trees For Shade
Strategic planting can also provide shade to your interior, says Harding. When planning your garden to boost natural cooling, consider:
Planting trees to channel breezes and funnel cool air into your home.
Positioning deciduous trees near windows and openings to block summer sun and allow for winter sun.
Planting trees at different heights to create seasonal shading.
Here at Hurst Homes we are big on energy efficiency as were are HIA GreenSmart Professionals. We custom design all of our homes, from the solar orientation of your home, to insulation and double glazing, and the heating and cooling appliances we install. We ensure your needs are met and running costs that be be reduced are where possible. We also get all of our homes individually energy rated for our clients so they know how their house compares to others when they go to sell. For a free preliminary estimate on your dream home contact us today on 0438 692 962.
For more tips from the Houzz experts visit Houzz.com.au