Orientation

What is orientation?

Orientation is how a building is positioned in relation to the sun’s paths in different seasons, as well as to prevailing wind patterns. In passive design, it is also about how living and sleeping areas are designed and positioned, either to take advantage of the sun and wind, or be protected from their effects.

Why is good orientation important?

Principles of good orientation

To achieve good orientation, the most important factors to consider are:

• the climate of your region
• true north and sun angles for your site or building
• optimum building design for your climate zone
• the effects of climate change.

Ideally, you should choose a site or home with good orientation for the climate in your region, and build or renovate to maximise the site’s potential for passive heating and passive cooling.

Your climate

Your climate will dictate your heating and cooling needs, and thus the best orientation for your home. Some climates need mainly passive heating, some need passive cooling, and most need a combination of both. Bear in mind that the climate is warming, and hotter summers with more extreme heat waves will become the norm during your home’s lifetime.

To understand your climate, you can first check your climate zone. This will give you a broad idea of your heating and cooling needs in each season. You can also conduct research to find out more about your local conditions, especially prevailing breezes.

True north and sun angles

In Australia, the main solar access comes from the sun’s path in the north. When people talk about orientation, they generally mean how your house – and especially living spaces – are orientated with regard to true or ‘solar’ north.

All references to north in Your Home are to solar north, not magnetic north.

True or solar north is not the same as magnetic north. Solar north can be significantly different from magnetic north, depending on where you live.

To determine the appropriate orientation for your home, you will need to establish true or solar north for your location. Use maps, a street directory, or a compass to establish magnetic north and then estimate true or solar north by adding or subtracting the ‘magnetic variation’ for your location using the following map. Most smartphones have a compass app that can be set to show true north.

You will also need to determine the sun angle in different seasons for your region, because the position of the sun varies across regions. Knowing the angle of the sun at different times of the day and different seasons will allow you to design window and shading elements to best capture or block solar access, depending on your needs.

Orientation for your climate

North-facing walls and windows receive more solar radiation in winter than in summer because the sun is lower in the sky. East- and west-facing walls and windows receive more sun in summer in the early morning and late afternoon when the sun is lower in the sky.

Your building design and how you treat north-facing walls will determine how much solar access your home receives.

How much solar access you want will depend on your climate zone. Briefly (remembering that these climate zones are averages, and each site will have unique characteristics):

• In Climate zone 1 (Hot humid summer, warm winter), Climate zone 2 (Warm humid summer, mild winter) and Climate zone 3 (Hot dry summer, warm winter), aim to use design and shading to minimise direct sun on all façades, while capturing and funnelling cooling breezes. In these climate zones, in locations at higher altitude on the Great Dividing Range or in the inland arid zones, solar access to north façades is recommended.
• In Climate zone 4 (Hot dry summer, cool winter), Climate zone 5 (Warm temperate) and Climate zone 6 (Mild temperate), the aim is to balance winter sun and summer shade. North orientation of living spaces is desirable, because the position of the sun in the sky allows full sun access in winter. In these climates you can easily shade northern façades in summer with simple horizontal devices such as eaves.
• In Climate zone 7 (Cool temperate) and Climate zone 8 (Alpine), the aim is to maximise solar access. North orientation of living spaces, combined with appropriate glazing and thermal mass, will enable you to take best advantage of solar access to heat your home.

Climate change

When deciding the best orientation for your home, bear in mind that the climate is warming. Hotter summers with more extreme heat waves are becoming more frequent. Passive heating is still very desirable in most climate zones, but passive cooling is becoming more important. Additional attention to shading of windows and walls (particularly west facing) and exposure to cool breezes and other forms of natural cooling is needed.

Orientation for passive heating

Orientation for passive heating is about using the sun to heat your home in winter and keeping unwanted summer sun out. Orientation for passive heating is most suitable for parts of Climate zone 3 and Climate zones 4–8.
 

Photo: Huw Matheson

In most climates, passive heating can be achieved relatively easily by locating living areas and windows on north-facing walls to let in low-angle winter sun and using horizontal shading devices to exclude high-angle summer sun.

Source: Dr Holger Willrath, Solar Logic

The best orientation for living areas is solar north; however, orientations of up to 15° west of north and 25° east of north still allow good passive sun access.

Variations in orientation towards east and west can even have advantages in some climates and for some activities. For example, in cold climates, orientating your home slightly west of north increases solar gains in the afternoon when they are most desirable for evening comfort, but east of north can warm the living areas of the home more in the mornings, improving daytime comfort for those people who are at home then. In warmer climates, orientating your home to capture local breezes will improve comfort. Breezes will vary from site to site depending on local topography and climate zone.

Poor orientation and lack of appropriate shading can exclude winter sun and cause overheating in summer by allowing low-angle east or west sun to strike glass surfaces at more direct angles, increasing solar gains.

The site

For good passive heating, choose a site that can accommodate north-facing living areas. Good orientation can be achieved on blocks of all different directions.

Source: AMCORD

However, achieving good solar access on smaller sites is more likely on north–south blocks because they receive good access to northern sun with minimum potential for overshadowing by neighbouring houses. In summer, neighbouring houses can provide protection from low east and west sun.

Narrow blocks with tall neighbouring houses may limit the options for solar access. On narrow blocks, careful design is required to ensure there is enough north-facing glass for adequate passive solar heating.

North–south sites on the north side of the street allow north-facing living areas and gardens to be located at the rear of the house for privacy.

North–south sites on the south side of the street should be wide enough to accommodate an entry at the front as well as private north-facing living areas. You can set the house back to accommodate a north-facing garden and consider creating a private outdoor living courtyard with plantings or even a garage on the northern boundary where planning permits.

Sites running east–west should be wide enough to accommodate north-facing outdoor space. Overshadowing by neighbouring houses is more likely on these sites — particularly if multilevel housing is permitted — because winter sun is lower in the sky, particularly in southern latitudes.

A north-facing slope increases the potential for access to northern sun and is ideal for higher housing densities. A south-facing slope increases the potential for overshadowing. Your design for solar access should not compromise that of your neighbours.

Source: AMCORD

Smaller individual lots in a subdivision are ideally located on north-facing slopes where they still receive solar access at increased densities.

South-facing slopes can be better suited to medium density if design strategies are used to overcome the impacts of overshadowing. For example, party walls can be designed to provide thermal buffers and smaller floor areas can be solar heated with carefully designed and shaded east- or west-facing windows using the right type of glazing.

The home

For passive heating, the ideal orientation for living areas is within 15° west and 20° east of true or solar north. Standard eave overhangs will allow winter sun to heat the building and exclude summer sun with no effort from the occupants and no additional cost. Poor orientation can exclude winter sun and cause overheating in summer by allowing low-angle east or west sun to strike glass surfaces.

Buying a home

• Choose a home with living spaces that have good access to winter sun. Look for a suitable area of glass on north-facing walls with access to winter sun; as a general guide this should be 10–25% of the exposed thermal mass floor area of the room.
• Check that there is not too much west-facing glazing and that it is properly shaded to prevent overheating. Bear in mind that external shading devices can be added later.
• Check that there is no significant overshadowing of windows and roof by nearby buildings and trees.

Source: Sustainable Energy Authority Victoria

Building a new home

• Build close to the south boundary of the site to protect solar access and maximise sunny, north-facing outdoor living areas, while ensuring you do not cause overshadowing to southern neighbours.
• Locate living areas on the north side of the home to take advantage of winter sun and locate openings to capture cooling summer breezes, taking care to ensure proper shading as well.
• Use smaller, well-shaded windows to increase cross-ventilation to the south, east and west.
• If your view is to the south, avoid using large areas of glass to minimise winter heat loss, and ensure the glazing is well insulated with double glazing and thermally broken frames.
• Avoid west-facing bedrooms to maintain sleeping comfort.
• Locate utility areas (laundries, bathrooms and garages) on the south or west side, where possible.
• Plant deciduous vegetation on the north side to allow winter sun in but provide summer shade.
• Landscape using fences and plantings to funnel cool breezes and block or filter harsh winds.

Choosing a home off the plan

• Choose a design that allows daytime living areas to face between 15° west of north and 20° east of true north on your site. Most off-the-plan builders will mirror or flip a design to suit your needs at no extra cost.
• Turn north-facing covered verandas into pergolas by replacing roofing material such as tiles or metal with slats or louvres, particularly over window areas.
• Reduce the amount of south-, east- and especially west-facing glazing, or relocate some to north-facing walls.
• Shade east- and west-facing glass by adding or relocating shade structures, such as verandas and deep covered balconies.

Choosing an apartment

• Choose an apartment with good orientation because external modifications such as shading are often prohibited by owners corporation rules. North-east corner units, north–south cross-over (split level) or cross-through (one side to the other) are ideal. Avoid units facing west.
• Look for solar access to living areas.
• Look for north-facing living areas and balconies or sheltered balconies or courtyards with winter solar access.

Renovating

• Adjust floor plan and orientation to trap the winter sun and encourage summer breeze flow by adding new windows, changing openings and relocating rooms.
• Relocate living areas to the northern side of the home to take advantage of winter sun and cooling summer breezes.
• Increase glazing on north-facing living areas.
• Prune vegetation that blocks winter sun; alternatively plant deciduous vegetation that allows winter sun in but provides summer shade.
• Plant shade trees in appropriate locations; landscape to funnel cool breezes and block or filter harsh winds. 

• Prune vegetation that blocks winter sun; alternatively plant deciduous vegetation that allows winter sun in but provides summer shade.
• Plant shade trees in appropriate locations; landscape to funnel cool breezes and block or filter harsh winds.

Orientation for passive cooling

Orientation for passive cooling keeps out unwanted sun and hot winds while ensuring access to cooling breezes. Some passive cooling is required in most Australian climates. In hot humid climates that do not have cool winters, orientation should generally exclude direct sunlight and radiant heat (from nearby structures) at all times of the year while maximising access to cooling breezes. However, note that some localities in these climate zones (higher altitude or arid zones) will still benefit from winter sun access.

The site

In tropical areas, northerly solar access is not desirable. Land with a south-facing slope provides increased shade. South is ideal for views because south-facing windows require minimal shading.

In all warm climates, look for a site with good access to cooling breezes. Ensure that landscape and adjacent buildings funnel rather than block beneficial breezes and provide shade to all walls.

Cool breezes can come from a range of directions depending on your region. For example:

• near the coast, breezes are generally onshore
• in many inland areas, there are no regular breezes during the day; however, at night, cool air currents can form as cooling night air flows down slopes and valleys
• in flat inland regions, brief thermal currents created by day–night (diurnal) temperature differences occur later at night or in early morning.

You can find out about the prevailing winds in your area on the Bureau of Meteorology’s website. These data will relate to the specific location of the weather station. Because winds are also influenced by local topography, combining the data with detailed local knowledge is always ideal.

Breezes can be diverted, so find a way to direct them through your home using fences, outbuildings, plantings and windows.

The home

For passive cooling, choose or design a home with limited or no exposure to direct sun and maximum exposure to cooling breezes. Use careful design to improve performance in the case of poorly orientated sites or existing homes.

Buying a home

• Choose a narrow, elongated or articulated building to facilitate passive cooling.
• Look for shading for north-facing windows.
• Avoid west-facing walls and windows if possible, because they receive the strongest radiation at the hottest part of the day.
• Look for 100% openable windows that face prevailing breezes. Also look for 100% openable windows or openable insulated panels located on more than one side of a room to improve ventilation and optimise overnight radiant cooling.
• Look for shaded outdoor living areas (courtyards, verandas and balconies).

Building a new home

• Design narrow buildings with long walls orientated to cooling breezes.
• Configure rooms to capture and encourage the flow-through of prevailing breezes, and position door and window openings to improve cross-ventilation paths.
• Minimise east- and west-facing openings because they receive the strongest sun and are the most difficult to shade; however, if they are needed for ventilation, ensure they are well shaded.
• Use generous climate-appropriate eave overhangs (including on the south in buildings above the tropic of Capricorn).

Choosing a home off the plan

• Choose a home designed and built from materials that suit your climate.
• Make sure your design can be positioned on your site to capture cooling breezes and has a minimal area of west-facing windows.
• Mirror or flip the design to suit your site and breeze paths.
• Locate windows or doors to the optimal location to capture cooling breezes.
• Make sure windows have significant openable area for ventilation (casement or louvre).
• Ensure all openings are shaded by eaves or devices of an appropriate width.
• Include south eaves in tropical climates.
• Opt for an open carport (not a closed garage) to allow for breezes.

Choosing an apartment

• Choose an apartment with good orientation because external modifications such as shading are often prohibited by owners corporation rules. North-east corner units, north–south cross-over (split level) or cross-through (one side to the other) are ideal. Avoid units facing west.
• Look for passive shading to north-facing glass or well-designed adjustable shading to east- and west-facing glass.
• Look for south-facing balconies or north-facing balconies with good shading.
• Look for well-designed cross-ventilation to distribute cooling breezes.

Renovating

• Reconfigure rooms to capture and encourage the flow-through of cooling breezes.
• Position door and window openings to improve cross-ventilation paths.
• Add windows to allow for cross-ventilation and night purging.
• Add shading on windows and outdoor areas.
• Block east- and west-facing openings or add shading.

Orientation for challenging sites

Small blocks

Designing a house with ideal solar orientation can be challenging on a small block. The following diagrams show how good orientation principles might be applied on small lots in eastern Australia. Breeze and wind directions should be reversed for Western Australia and adapted to suit local conditions in other regions. The passive heating principles remain the same.

For cool or cold climates the orientation in the following diagram maximises late afternoon solar gains and allows morning sun in winter. It excludes summer sun from west and south-facing windows and minimises exposure to westerly winds while allowing reasonable breeze access.

Dense planting to the west shades walls from summer sun and protects them from cold winter winds.

This configuration is also useful in warmer climates where cooling breezes are from the south-east. Use bigger overhangs on north eaves to reduce solar gains in spring and autumn in these climates. Breeze-filtering plantings to the east provide shade from morning sun in summer.

Source: Adapted from Suntech Design

For warm temperature climates, the orientation shown below maximises exposure to cooling breezes but reduces passive solar heat gains. It requires shade plantings to the west to eliminate solar gains through south-facing windows in summer and protect the house from westerly winds.

In warmer climates, shade plantings on the east are also required but should not block breezes. Clerestory windows along the spine of the house can increase solar and breeze access to sleeping areas.

Source: Adapted from Suntech Design

For temperate climates, a simple configuration (diagram below) allows for passive heating of living areas during the day, and cooler, southerly sleeping areas during the night.

In cooler climates, a thermal mass wall separating these zones would transfer solar warmth to sleeping areas.

In warmer regions, passively shaded clerestory windows along the spine of the house would allow hot air to escape from bedrooms in summer while allowing in a small amount of winter sun.

Source: Suntech Design

For hot humid climates, the orientation shown below suits Darwin, where cool breezes come predominantly from the north-west, and it can be simply reconfigured for east- or west-coast tropical sites.

It divides the home into separate pavilions to maximise the cross-flow of breezes. Canopy trees partially overhang the roof and shade all walls without blocking breezes. Where such shading can’t be achieved, an elongated east–west floor plan will limit low solar access to east and west walls.

Both the building form and understorey plantings are designed to funnel breezes into the building and allow them to escape.

A pavilion design allows hybrid cooling, where 2 pavilions might be free-running and the third designed and insulated for air-conditioning. Installing a thermal mass dividing wall in the third pavilion with non-air-conditioned sleeping spaces behind it would help create night-time sleeping comfort after the early evening air-conditioning is switched off.

Source: Suntech Design

Limited solar access, no solar access, or no cooling breeze access

On sites with poor orientation or limited solar access, high levels of thermal performance are still achievable through careful use of different strategies and systems. Strategies include:

• low mass construction 
• sealing your home 
• carefully designed glazing and shading systems 
• hydronic heating that ‘borrows’ solar energy from the roof and distributes it to the house.

• Beagley S (2011). Greenhouse friendly design for the tropics,[PDF], COOLmob, Northern Territory Government, Darwin.
• Bureau of Meteorology (BOM). Wind roses for selected locations in Australia.
• Cole G (2011). Residential passive design for temperate climates, Acumen, EDG 66 GC, February, Australian Institute of Architects.  
• Department of Housing and Regional Development (1995). AMCORD: a national resource document for residential development, Commonwealth of Australia, Canberra.
• Hollo N (2011). Warm house cool house: inspirational designs for low-energy housing, 2nd edn, Choice Books, NewSouth Publishing, Sydney.
• Sustainability Victoria (2020), Energy smart housing manual.
• Wrigley D (2012). Making your home sustainable: a guide to retrofitting, rev. edn, Scribe Publications, Brunswick, Vic.

Learn more

• Explore Design for climate to make sure your design suits the climate in your region
• Refer to Passive heating for more information on improving thermal performance
• Read Building rating tools to find out how using these tools can improve your design

Authors

Original author: Caitlin McGee

Contributing authors: Chris Reardon, Dick Clarke

Updated: Dick Clarke 2020