The direction a house faces shapes how it feels every day. It affects how warm the living room gets in July and how hot the bedrooms are in January. Getting it right is easiest at the design stage. Getting it wrong can mean years of higher heating and cooling bills.
This guide covers the basics of orientation for Australian homes. It draws on the federal government’s Your Home guide to sustainable house design. The ideas apply to new builds and to renovations alike.
Why the sun’s path matters
In Australia, most useful sun comes from the north. Winter sun sits low in the sky and reaches deep into rooms that face it. Summer sun sits higher and is easier to block with a simple overhang. That difference is the basis of passive solar design.
The federal guide on orienting your home says good orientation can greatly reduce the need for heating and cooling. It also points out that the best approach depends on your climate zone. A design that suits Hobart will not suit Darwin. So the first step is knowing which zone your block sits in.
Finding solar north
Orientation is measured from solar north, also called true north. This is not the same as the north on a compass. A compass points to magnetic north, and the gap between the two varies across the country.
Your Home suggests starting with magnetic north and adding or subtracting the local magnetic variation. Many smartphone compass apps can also show true north directly. Check this on site before the plans are drawn. Your designer can then mark it clearly on the site plan.
Matching the design to your climate
Your Home groups Australia into climate zones and gives broad advice for each. In the hot humid, warm humid and hot dry zones, the aim is to keep direct sun off the walls as much as possible. Catching and funnelling cooling breezes matters more than winter warmth. The guide notes that higher parts of the Great Dividing Range and inland arid areas still benefit from northern sun.
In the temperate zones, which cover much of southern Australia, the goal is balance. Living spaces that face north get full winter sun. Simple horizontal shading such as eaves can keep out the high summer sun. Cool temperate and alpine zones go further, aiming for as much winter sun as possible with suitable glazing and thermal mass.
The guide also takes a longer view. Hotter summers and more intense heatwaves are expected over the life of a house. That makes shade and access to cooling breezes more valuable as time goes on. A house designed today has to cope with the climate of the coming decades.
How far off north is still fine
Few blocks line up perfectly with the compass. Your Home says living areas work best facing solar north. It also says some angle away from north still allows good passive heating. Its suggested range runs up to about 15 degrees west of north and around 20 to 25 degrees east.
For glass, the guide offers a rough rule of thumb. North facing glass should be about 10 to 25 percent of the floor area of the room’s exposed thermal mass. Too little glass and the room misses out on free winter warmth. The right figure depends on the room and the climate, so ask your designer to check it.
Where each room should go
Once you know where north is, the floor plan starts to sort itself out. The aim is to put the rooms you use most during the day where winter sun can reach them. Rooms you use briefly can act as a buffer on the harder sides. The NSW Government’s BASIX orientation and siting guidance follows the same pattern.
- Living areas on the north side, opening onto outdoor space that gets winter sun
- Laundries, bathrooms and garages on the south or west where possible
- Bedrooms away from the west, since late afternoon heat makes sleep harder
- Fewer windows on the east and west, where the sun is strongest and hardest to shade
Wet areas often end up on the south side for this reason. That placement does not have to make them dark or dull. Our guide to modern bathroom design covers ways to plan light and finishes in these rooms. Kitchens need similar thought, and many common kitchen design mistakes start with poor placement on the plan.
Shading east and west windows
Low morning and afternoon sun is the hardest to control. It comes in at a flat angle, so eaves do little to stop it. Your Home warns that west facing walls and glass take the strongest heat at the hottest part of the day. Where you do need windows on these sides, plan the shade from the start.
The guide suggests verandas, deep balconies or adjustable shading for east and west glass. Dense planting on the west can shade walls and also block cold winter winds. In cooler climates, deciduous plants on the north let winter sun through and give shade in summer. This is where house and garden design need to work together, and a professional landscape designer can plan planting that does the job.
Making the most of an awkward block
Good orientation is possible on almost any block, according to Your Home. Blocks that run north to south give the best solar access on small sites. On a block with the street to the south, living areas and gardens can face north at the rear for privacy. On a block with the street to the north, the lot needs enough width for a front entry plus private living space that faces north.
East to west blocks are harder. They need enough width for outdoor space that faces north, and they are more prone to overshadowing. Narrow blocks with tall houses next door also need careful design to get enough northern glass. A slope that faces south increases overshadowing as well. The guide adds that a new design should not take away a neighbour’s solar access.
Improving orientation in a renovation
You cannot turn an existing house around, but you can change how it uses the sun. Your Home suggests moving living areas to the north side where the layout allows. Openings can be added or changed to catch winter sun and summer breezes. Glazing on north facing living areas can also be increased.
Small changes help too. Prune vegetation that blocks winter sun, or replace it with deciduous species. A solid veranda roof on the north can become a pergola with slats or louvres. For apartments, owners corporation rules often limit outside changes, so the choice of unit matters more.
Orientation decisions also touch the roof. If solar panels are part of the plan, think about roof planes at the same time as the room layout. It helps to understand the financial feasibility of a solar energy system before the roof design is fixed.
Frequently asked questions
Is solar north the same as compass north?
No, they are different. A compass shows magnetic north. Solar north is found by adjusting for the local magnetic variation, and many phone compass apps can show it.
Which rooms should face north?
Living areas you use during the day should face north. They gain the most from winter sun. Outdoor living space on the same side works well with them.
Do eaves matter in a hot climate?
Yes, shade matters most in hot climates. Your Home recommends generous eaves suited to the climate, including on the south side in tropical areas. The aim is to keep direct sun off walls and glass.
Can I fix a poorly oriented house?
Not entirely, but a renovation can help a lot. Moving living areas north, changing windows and adding shade all make a difference. Pruning or replanting trees is a simple place to start.
This article is general information only. Building rules and energy requirements differ between states and councils, so check with your local council and a qualified designer before you build.
