North-facing is not always what you think in Australia

"North-facing" is the most common phrase in Australian property listings after "renovated kitchen". For Southern Hemisphere properties, a north aspect gets the sun all day, warms the living room in winter, and supports solar panels on the right roof face.

But "north-facing" is not always what you think. Three different "norths" exist on any Australian property document, and they do not align. The confusion can cost you a misplaced solar array, an overheated west-facing kitchen sold as "northern aspect", or a winter sun angle that misses your living room by 6 metres.

This post unpacks the three norths and how to use the right one for the right question.

The three norths

True north (geographic / solar north)

The direction of the geographic North Pole. The direction the sun reaches at solar noon (the highest point of its daily path). The reference for solar access, panel orientation, garden design, and shadow calculations.

True north on a property document is typically marked with a small star symbol or an arrow labelled "N".

Grid north

The vertical direction on the council's grid coordinate system. Almost all Australian council mapping uses a grid that is rotated slightly from true north to accommodate the curvature of the Earth's surface.

The difference between true north and grid north is typically 0.5 to 2 degrees across Australia. Small enough to ignore for most purposes.

Magnetic north

The direction a compass needle points. Magnetic north drifts over time as Earth's magnetic field shifts. In 2026, the magnetic declination across Australia varies from about 4 degrees east of true (Perth) to 12 degrees east of true (north-east Queensland).

For property purposes, magnetic north is rarely relevant unless you are surveying without GPS.

Why the difference matters

For most residential decisions in Australia, the difference between true north and grid north is small. But two specific situations are large enough to matter:

1. Solar panel orientation

Solar panels should ideally face true north for maximum annual yield. If your roof is "north-facing" according to the lot map (grid north) but actually 7 degrees west of true (e.g. in north-east Queensland), your solar yield is reduced by 1-3% compared to a true-north-facing array.

For a 6.6 kW system over 15 years, a 2% yield loss is roughly $2,500-3,500 of lost feed-in revenue and self-consumption savings. Small per year. Real over the system life.

2. Habitable-room solar access for council DA

Council DCPs require new dwellings to demonstrate solar access to habitable rooms (typically the living room) for a minimum number of hours on the winter solstice (June 21).

The solar access calculation uses true north, not grid north. A buyer who orients the living room toward "north" on the site plan (grid north) may discover the actual solar access on June 21 is less than required because the sun arc tracks true north, which is 5-7 degrees off the grid orientation in some areas.

If the difference is significant, the building's design has to change. The window has to widen. Eaves have to be redesigned. Cost: $4,000-12,000 in design changes if caught late.

Where the difference is largest

True-north vs grid-north divergence is largest in:

• Far north Queensland (Cape York, Cairns): up to 8 degrees
• North-west Australia (Kimberley, Pilbara): up to 7 degrees
• South-west WA: 4-6 degrees
• South-east Tasmania: 4-5 degrees

The divergence is smallest in:

• East coast major cities (Sydney, Melbourne, Brisbane): 1-3 degrees
• Adelaide: 2-3 degrees

For most urban Australian properties, the divergence is small enough to ignore. For rural and far-northern properties, the divergence is large enough to plan around.

How to read the right north for the right question

Three habits:

Solar panel orientation

Use true north. Most solar installers know this. If the installer's quote shows the panels "facing north on the property map" without specifying which north, ask. The good installers use true north as their default.

Council DA solar access analysis

Use true north. The DCP solar access requirement is calculated using actual sun paths, which follow true north. If your architect's solar access diagram uses grid north, the calculation may be wrong.

Property listings and casual descriptions

Use grid north. When the agent says "north-facing backyard", they mean according to the lot map, not according to the sun. The casual usage is fine for shorthand, but apply the divergence when it matters.

Garden design and outdoor furniture placement

Use true north. The sun arc determines where the shade falls and which corner is sunny in winter. The lot map will lead you wrong.

The 30-second check

For any property, open the lot's contour map or aerial photo with a north arrow. Then check the true-north arrow on a topographic map (e.g. NSW SIX Maps, QLD QSpatial) at the same location. The angle between the two arrows is the divergence.

If the divergence is under 3 degrees, you can ignore it. If it is over 5 degrees and you are planning solar or new construction, apply the correction.

Why this matters most for new builds

For an existing dwelling, the divergence is baked in. The kitchen is where it is. The solar panels are where they are. You can adjust at the margins but the major decisions are fixed.

For a new build, the divergence affects every design decision. The architect's first-pass site plan uses grid north (it is what the cadastral plan provides). The actual solar performance requires true north. The two have to be reconciled, ideally early in design, not late.

"North-facing" is shorthand. The shorthand works for most casual conversation. It does not work for design, solar, or anything that depends on the actual sun. Knowing which north you are talking about is the difference between a property that delivers the warm winter light you imagined and one that misses by 6 metres.