Passive Solar Design
Explore our collection of Passive Solar Design
featured on Lunchbox Architect.
"In passive solar building design, windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer. This is called passive solar design or climatic design because, unlike active solar heating systems, it doesn't involve the use of mechanical and electrical devices." -- Wikipedia
Would you believe a house using Passive Solar Design principles often doesn't need any additional heating or cooling? All it needs is free energy from the sun — not even fancy photovoltaic cells or complicated heat transfer systems.
Think of how much money and energy you would save if you didn't have to pay for heating and cooling — 40% in most cases (and much more in some climates).
That's extra cash you could be spending on fine dining and cocktails!
A Passive Solar House relies on six basic principles. If you get these principles right, you could eliminate your heating and cooling bills for good:
Climate
Passive Solar Design principles vary depending on your climate. In the tropics, using the sun to heat your homes would obviously be a bad move. Instead, cooling and ventilation is much more important. Whereas in Alpine areas, the house will probably never need cooling to maintain a comfortable indoor temperature. Temperate climates fall somewhere in the middle, usually requiring heating in the winter and cooling in the summer.
So, based on your climate, a Passive Solar Design will look and behave differently. In the tropics, large overhanging eaves shade the home from the sun and ventilation is essential to keep to space cool. While in cooler climates, eaves are sized to let the low winter sun in to warm up the home, while blocking out higher summer sun.
Orientation
Because Passive Solar Design relies on the movement of the sun, orienting your home correctly is essential. In Australia (and other countries in the Southern Hemisphere), the ideal location of windows for Winter heat gain is North, because the sun rises in the East and travels through the North sky before setting in the West.
In Europe, North America and other areas in the Northern Hemisphere, the opposite is true. The sun still rises in the East and sets in the West, but it travels through the Southern sky, so for maximum Winter sun, windows should face South.
Shading
Let's not forget shading. In the tropics shading is super important to keep the home cooler throughout the year. With the exception of the most frigid climates some level of shading is important in cooler climates as well to prevent overheating in Summer.
Because the sun is higher in Summer than in Winter, shading devices in temperate climates can be designed to block out the Summer sun, but still allow the Winter sun in.
Deciduous trees or creepers are another way to shade windows because they work in sync with the seasons. In Summer, lush green leaves will protect your home from the sun. In Winter the plant drops its leaves to let the sun shine in.
Thermal Mass
Have you ever stepped on or touched concrete after the sun has set to find it's still toasty warm? That's because concrete is great thermal mass — it absorbs and then holds heat for a long time. Materials with high thermal mass (like concrete, brick and even water) are like a thermal bank account. When times are good and the sun is shining they'll absorb the heat energy. Then, when that heat disappears (when it's cloudy or the sun has set) they'll slowly release that heat back into the atmosphere. When used in a home, this helps to moderate the temperature between the day and night.
The reverse is also true, if you cool down concrete or any other material high in thermal mass, it will stay cool for a long time, radiating that 'coolth' back into atmosphere.
When used correctly, thermal mass is a great way to store the sun's energy to keep the house warmer at night or when it clouds over. In summer (or tropical climates), the thermal mass can be used to keep the home cooler.
Ventilation
In many climates, cooling is just as important (if not more important) as heating. So how does Passive Solar Design cool a house? The sun itself isn't very good at cooling!
The key is ventilation.
Passive ventilation replaces hot, stale air with fresh, cooler air. Techniques like the stack effect achieve this replacement very efficiently. Depending on the site and climate, you might also be able to capture natural cool breezes, like evening sea breezes, for example.
Our bodies are pretty good at moderating our own thermal comfort. Perspiration, for example helps to keep us cool. But perspiration only works when the moisture can be evaporated off our skin — enter ventilation. A decent breeze can keep us feeling comfortable even in extremely hot conditions.
So ensuring the home has good ventilation — particularly cross ventilation — and encouraging the air to be drawn into the home from the cooler, shady side of the house will keep the house cool and comfortable even during the peak of summer.
Combine good ventilation with thermal mass and you can use the cooler night air to keep the house much cooler during the day.
Insulation
The final key principle of Passive Solar Design is insulation. Insulation in temperate and cooler climates is incredibly important. All our efforts to passively heat or cool the home will be lost if the home isn't well insulated from the outdoor temperatures.
The type and extent of insulation will vary depending on your climate. Tropical climates will require little to no insulation, while a very cold climate will need double or triple-glazed windows and very thick bulk insulation in the walls to keep the warm air inside.
It's particularly important in a Passive Solar Design to insulate the thermal mass from the outdoor extremes. This will help the thermal mass to moderate the temperature of your home day and night and season to season.
Thinking About Passive Solar Design
A good architect will consider Passive Solar Design as a matter of course. Passive Solar Design isn't a fancy additional extra. For the most part it doesn't cost any more — in fact over the life of your building it can save serious money. It's easy to achieve with new buildings and improvements can often be made even in poorly designed existing buildings.
There's really nothing better than basking in warm, natural sunlight in your comfortable, efficient home when it's freezing cold out, or opening up your house to cooling natural breezes on a warm Summer's night. Passive Solar Designed homes are more comfortable year round, cheaper to run, and much friendlier to the environment.
Check out some of the projects using Passive Solar Design featured on Lunchbox Architect:
The architectural equivalent of a lamington made with Swiss cheese and dusted with paprika sounds like a recipe for disaster, but is it?
To unite all living spaces without creating one large space, a unique nest-like studio sits above the living area in this reno.
This heritage home has been renovated with new living spaces. A covered outdoor space ties all these new spaces together.
By working with the original roofline of this Federation home, the designer created a light-filled and spacious addition.
This home manages to be thoroughly modern while mimicking the classic gabled form of children's drawings and doll's houses.
Application of passive design principles creates a living, breathing, sustainable space that is a pleasure to inhabit.
This new living space is a sun-lover. Turning to face the sun, it is also a fun and happy space, not to mention a cost-saver.
What do you do with a triangular site? Perhaps the best solution is to think outside of the box. Or triangle, as the case may be...
As Torquay becomes increasingly cosmopolitan with more permanent residents architects are rethinking the traditional Aussie beach house.
A new living pavilion built from concrete blocks and with large windows facing the sun contrasts with the original weatherboard home.
Just a short walk from the beach and surrounded by Moona trees, a central courtyard is the link between this home and the landscape.
Tucked away in Noosa's bushy hinterland is a tent house - a place that gives the sense of permanent camping without sacrifice...
A studio connected to the main house by a decked walkway creates maximum flexibility (and reduces renovation stress) for this family.
Built for a family bursting with creative souls, this shack needed to be as stylish and as interesting as the people living in it.
Built from recycled timber and rusting steel, this Mt Duneed home already looks old, yet is built to last with little maintenance.
Built on a challenging site with significant bushfire risk, this home enjoys amazing views over bushland in the Macedon Ranges.
Staff quarters never looked so good. This prefab house is a modern and comfortable place to wind down after a long day on the farm.
House_B is essentially a C-shape, wrapping around a central courtyard to maximise light and breezes to the home. That gets an A+ from us.
Inspired by Mid-century design with a touch of Aussie shed, this stylish shack is the perfect combination of cool and practical.
A passive design and solar panels creates a comfortable house year-round which also generates income for this family.
Designing a family home is challenging because the family's needs change as they grow, that's why you have to plan for change.
Every square metre counts when you don't have much space. You need to be smart and make every element do more than one thing...
What happens if you take historic Adelaide housing and give it a modern, considered and environmentally conscious twist?
For cost efficiency this project creates two identical houses, but thanks to a clever folded facade each home fits the site.
A renovation creates flexible but calm spaces for a blended family, visiting overseas relatives, and a professional home office.
This renovation for a woman with a busy work life needed to be relaxing and low-maintenance - the perfect retreat after a long day.
Supporting the clients' desire for a sustainable lifestyle, this off-grid home uses passive solar design to reduce energy consumption.
At this highly visible corner block, the architects have designed a black extension to contrast with the white Edwardian original.
With sliding doors and a fold down bed, a rumpus room/third bedroom provides built in flexibility while reducing the overall footprint.
From the street this modern take on the other single storey cottage in the neighbourhood. But things get interesting quickly...
A deceptively simple and elegant addition which could be considered a prototype for sustainable, affordable homes.
Even after a reduction in total size, this renovation works better than the previous cluster of poorly considered renovations.
Old and new are connected by a black tunnel with no end immediately in sight. But there is a light-filled end to this tunnel.
It takes a lot of 'stuff' to run a family. Just because you're interested in sustainability doesn't mean you need to go without...
A rear extension takes advantage of a North-facing backyard to connect to the garden and generate electricity for the whole house.
With an ageing population our homes must be designed to allow us to live in them as long as possible. This house shows us how.
With the sun and a majestic tree in one direction and views of a distant nature reserve in the other, this home manages to have it all.
A 1970s-era weatherboard holiday house gets a serious revamp to make it perfect for Grandparents' retired living.
By building an extension at the end of a narrow site, Austin Maynard Architects created a courtyard instead of a typical light-well.
With a green roof and other sustainable elements this beach-side residence touches the earth lightly physically and metaphorically.
Carefully planned around a central courtyard to maximise light and connection to the garden while minimising its impact on the street.
A warm new home for a young family wraps around a courtyard space to create a protected area for the kids to play and the family to enjoy the stunning ocean views.
Studio 19 are at it again, designing two stunning community houses for a not-for-profit organisation in New Zealand.
Make space for Warm House Cool House on your bookshelf and your home can become a more sustainable and comfortable place.
A magnificent 100 year old fig tree and a small creek are treated as sacred elements in this home which embraces its environment.
There's not much diversity (or sustainability) in your average project home. With a bit of luck, Erpingham House will change all that.
In the Californian desert temperatures can soar to over 40 degrees. This family built a home without air-conditioning - are they mad?
While this modern farm house feels shiny and new, traditional elements like the generous verandah gives it the best of both worlds.
Defying gravity, a protected timber box for sleeping zones sits on top of a glass box for living in this renovation of a Sydney semi...
Sweeping views of hills, beach, rocks and ocean inspired the fan shaped plan of Fleurieu Beach House - a model for coastal living.
These homes are off the grid. They produce power, collect rainwater and treat their own waste - saving money and the planet at once.
A new home in a neighbourhood of large houses scales back the status quo to provide ‘just the right amount of space’ for a family.
Mills House eliminates bulky cupboards by converting the floor into storage space, leaving the entire width of the terrace for living.
This welcoming house has a verandah so generous it blurs the line between a courtyard house and a traditional Australian verandah.
In a natural clearing of bushland, this home with simple detailing and an earthy palette captures the spirit and joy of camping.
Rectifying a poorly planned '90s renovation this new courtyard arrangement lets in plenty of light and feels more spacious than ever.
A home previously owned by the client's Grandmother wasn't a good fit for a young family. An innovative extension changes all that.
This off-the-grid home is close to the beach in the Daintree Rainforest — an ancient ecosystem deserving a thoughtful approach to site.
Perched on top of a hill overlooking the stunning ocean along the Victoria's Great Ocean Road is a home that balances heavy and light.
A moderate extension creates a rich space and leaves a decent-sized backyard. Jack's House is a timber 'gusset' that will serve the family into the future.
Polygreen is a printed fiberglass box in a neighborhood of red brick warehouses. The contrast is striking - a home covered in vibrant green.
Andrew Maynard Architects asked a simple question -- 'Where does the sun come from' -- and designed a Hill House in the backyard of this Melbourne home.
Fairfield Hacienda offers an alternative to the often wasted front yard. MRTN Architects have created a sunny, private courtyard at the front of the house.
Thornbury House might appear haphazardly crooked, but the angled facade doubles as a sunshade. This solar passive home is functional and visually appealing.
Pump House is a compact, off-grid home for simple living. Owners and guests can enjoy a quiet night, a cup of tea and quality time with their horse, George.
At first glance it's a typical Victorian-era worker's cottage. Only on closer inspection you realize there's something unusual going on behind that facade...
This family want to live in their home forever. They just need an architect to create a home to suit them for years to come -- in just 3.6 meters width.
Mount Ninderry House is a sustainable house that takes full advantage of its stunning natural setting without the extra cost. And check out that pool!
Even during the heat of summer this passive solar design remained cool and kept the family comfortable. Reclaimed materials integrates with the original.
Snowy Mountains House is designed for living off the grid in style. The home works with nature to resist extreme winds, collect rainwater and shed snow.
Salt Creek Rural Retreat is a one bedroom, one bathroom sustainable accommodation. The tiny prefab building enjoys beautiful views over 20 acres.
Bridge House takes full advantage of a naturally stunning site, straddling a creek bed and touching the earth lightly environmentally and physically.
Southern Highlands House's new tiny work space, feels more like an art piece than an office - well proportioned, beautifully curved and effortlessly simple.
How exciting to unload an architecturally designed house off a truck, unwrap it (like a giant Christmas gift) and move straight in -- with Happy Haus, you can!
Tucked away in a subdivided backyard in Melbourne's Inner North, Nest Architects created a delightfully compact two-bedroom home with a beautiful sunny garden.
This modern replacement for a derelict weatherboard cottage takes full advantage of the sun, the surf and views of the rolling hills.
Eco-friendly Bruny Shore House reaches out from one of the steepest parts of the site to take in the dramatic Tasmanian coastline.
The 8.2-Star Energy Rated Leura Lane House is an impressive 2-bedroom prototype for energy efficient housing perfect for rural sites.
Rather than gutting and starting again, a simple reconfiguration was all it took to make this home brighter and more comfortable.
A modest, cement clad building sits deep on a north facing bank opening to the landscape and overlooking the valley and ocean below.
Despite only adding six square meters to this home, Welsh and Major's reconfiguration and tiny pavilion have made a dramatic difference.
A project home from the 1970s with poor solar orientation is reconfigured and realigned. Now it catches the sun for energy efficiency.
A bayside extension clad inside and out in timber battens blurs the functional and decorative.
Aireys Inlet House -- like all good second homes -- creates connection to nature in contrast to the clients' busy city lives.
A local shed company prefabricated this home, saving both time and cost. But Whyatt House doesn't look like a typical shed…
Ilma Grove is an extension to a heritage home in Northcote, Victoria. The extension provides more space and guarantees a sustainable lifestyle.
This small house is sustainable, low-maintenance, affordable and it's pre-fab so it arrives (practically) ready to move into.
This new shack takes better advantage of the views and has enough space to host this multi-generational family during the holiday season.
Thanks to the home's unusual form, the garden of Reverse Shadow Casting House will always be sunny and bright.
In an effort to find more space for a growing and ageing family, Andrew Maynard Architects created a home that has shared space and more private zones.
You can't see the sea from this modern beach house. Undeterred by the lack of view, it faces a sheltered internal courtyard instead.
A prefab home designed around passive solar design principles is warm, comfortable, energy efficient and looks prefab-ulous.
A modest, energy efficient home in New Zealand's spectacular wine country makes the most of sweeping views…
This passive solar home was designed to maximise available light and space on an oddly shaped block in the inner suburban Melbourne.
Designed in a flood-prone area, this modest, sustainable beach house touches the earth so lightly it appears to float!
Hereston Gardenhouse pops up in a disused back yard and demonstrates a way to make cities more dense and (importantly) sustainable.
