10 Ways Passive Solar Design Can Slash Your Energy Bills
The money you'll save over time is a powerful incentive to work with nature rather than against her during your new build or renovation
Liz Durnan
24 August 2014
Houzz Australia Contributor. Previously a freelance writer and editor at a variety of magazines and websites in London, New York and Sydney. Now I live in the Blue Mountains bush in a strawbale house that we built from scratch. I write about my passions – mainly books and sustainable housing – while writing a book and attempting a permaculture garden.
Houzz Australia Contributor. Previously a freelance writer and editor at a variety... More
Why pay for energy when you can get it for free? Not everyone has access to full northern exposure but if you have any access to some northern sunshine, it makes sense to cut your energy bills by harnessing the power of the sun. Here are 10 tips to design or renovate your home in a way that makes the most of passive solar principles.
1. Linger over layout
Position often-used rooms, like lounge rooms and home offices, to the north of the house to benefit from the free sunshine. Place lesser-used rooms, like laundries and utility rooms, on the colder, south side.
Position often-used rooms, like lounge rooms and home offices, to the north of the house to benefit from the free sunshine. Place lesser-used rooms, like laundries and utility rooms, on the colder, south side.
2. Plan furniture positions
Why sit by a heater when there’s a big free one in the sky? Place furniture so you can bask in direct or filtered sunlight. If the eaves are positioned correctly the sun will gradually enter the room by a few centimetres each day as we get further into winter. By the winter solstice north-facing rooms will be sun-drenched. As summer approaches the sun retreats and by December, should be excluded completely leaving the house cool.
Why sit by a heater when there’s a big free one in the sky? Place furniture so you can bask in direct or filtered sunlight. If the eaves are positioned correctly the sun will gradually enter the room by a few centimetres each day as we get further into winter. By the winter solstice north-facing rooms will be sun-drenched. As summer approaches the sun retreats and by December, should be excluded completely leaving the house cool.
3. Consider all the angles
The angle and size of the eaves is also crucial. Your architect or builder needs to design the eaves so that they allow the low angle of the sun to penetrate the building in winter and exclude the high angle of the sun in summer.
The angle and size of the eaves is also crucial. Your architect or builder needs to design the eaves so that they allow the low angle of the sun to penetrate the building in winter and exclude the high angle of the sun in summer.
4. Orientate your building
Time to make use of that compass you’ve had lying around for years. You first need to consider how your block or existing house is orientated. If you have a large block which fully faces north, maximise glazing on the north side. Minimise windows to the south and west. If the block allows, build a wide shallow house on an east-west axis for maximum solar gain.
Step inside this house
Time to make use of that compass you’ve had lying around for years. You first need to consider how your block or existing house is orientated. If you have a large block which fully faces north, maximise glazing on the north side. Minimise windows to the south and west. If the block allows, build a wide shallow house on an east-west axis for maximum solar gain.
Step inside this house
5. Factor in flooring materials
The best floors to absorb the maximum amount of heat from the sun, and retain it, are concrete and earth floors. Use rugs for extra warmth by all means, but position them so that some of the concrete is exposed to the sun for maximum heat gain.
See more of this house
The best floors to absorb the maximum amount of heat from the sun, and retain it, are concrete and earth floors. Use rugs for extra warmth by all means, but position them so that some of the concrete is exposed to the sun for maximum heat gain.
See more of this house
6. Consider blissful bathing
Many people place bathrooms and shower rooms on the cooler south side of a house, but what could be more luxurious than relaxing in a hot tub on a cold winter’s day with the sun streaming through? Think about placing at least one bathroom on the north side.
Many people place bathrooms and shower rooms on the cooler south side of a house, but what could be more luxurious than relaxing in a hot tub on a cold winter’s day with the sun streaming through? Think about placing at least one bathroom on the north side.
7. Garden your way to lower bills
Deciduous trees planted on the north side of the house or deciduous vines on a northern pergola will allow for shading in summer. When they shed their leaves in winter they let the sun shine through.
See more of this garden
Deciduous trees planted on the north side of the house or deciduous vines on a northern pergola will allow for shading in summer. When they shed their leaves in winter they let the sun shine through.
See more of this garden
8. Use window treatments to full advantage
There’s been a recent trend to go without any window dressings but unless you want a very minimalist look, curtains and blinds have a big role to play in a passive solar house. On large areas of northern glazing they give you more control over passive heating and cooling. Closing the curtains on a cold winter’s evening will lock in the heat that has built up during the day. Keeping them closed on a hot summer’s day will help keep rooms cool. Having a full block-out and a sheer layer allows for even more control of light and heat.
There’s been a recent trend to go without any window dressings but unless you want a very minimalist look, curtains and blinds have a big role to play in a passive solar house. On large areas of northern glazing they give you more control over passive heating and cooling. Closing the curtains on a cold winter’s evening will lock in the heat that has built up during the day. Keeping them closed on a hot summer’s day will help keep rooms cool. Having a full block-out and a sheer layer allows for even more control of light and heat.
9. Play it smart with window materials
To keep a house warm in winter and cool in summer, insulation plays an important role. Opt for double or even triple glazing in colder climates and if budget allows. The material used is crucial, too – timber has superior thermal properties to aluminium. It will keep heat in and out when needed. Opt for the best you can afford when it comes to windows – the money you spend will be saved in the long term on energy, especially as these costs rise. (Check the bushfire rating of your area to see if timber windows are allowed.)
See more of this cowshed conversion
To keep a house warm in winter and cool in summer, insulation plays an important role. Opt for double or even triple glazing in colder climates and if budget allows. The material used is crucial, too – timber has superior thermal properties to aluminium. It will keep heat in and out when needed. Opt for the best you can afford when it comes to windows – the money you spend will be saved in the long term on energy, especially as these costs rise. (Check the bushfire rating of your area to see if timber windows are allowed.)
See more of this cowshed conversion
10. Let the air flow
Window placement is all-important in a passive solar house. As well as maximum solar gain, ventilation needs to be considered. High windows that can be opened on a hot summer day allow a pleasant cross breeze. As heat rises, excess heat can be drawn from high windows. You need to consider the local climate; a home in the Snowy Mountains will of course have different design requirements than one in Far North Queensland.
YOU TELL US
Have you designed your house to make the most of the sun? Tell us about it in the comments section below.
MORE
Eco-Clever Ways to Embrace the Extreme Aussie Climate
11 Smart Ways to Go Greener Through Design
Greening Your Home: 10 Ways to Create an Eco-Friendly Workspace
Window placement is all-important in a passive solar house. As well as maximum solar gain, ventilation needs to be considered. High windows that can be opened on a hot summer day allow a pleasant cross breeze. As heat rises, excess heat can be drawn from high windows. You need to consider the local climate; a home in the Snowy Mountains will of course have different design requirements than one in Far North Queensland.
YOU TELL US
Have you designed your house to make the most of the sun? Tell us about it in the comments section below.
MORE
Eco-Clever Ways to Embrace the Extreme Aussie Climate
11 Smart Ways to Go Greener Through Design
Greening Your Home: 10 Ways to Create an Eco-Friendly Workspace
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I have a north facing house with living area facing south and electric opening clerestory windows facing north let in the winter sun and help remove the summer heat.