Safe clearance distances between buildings and powerlines are legally required to protect people and property. Electricity can flash over a gap. A person can be some distance from a powerline and still get an electric shock or severe burns.
You must allow for weather conditions when applying any safe clearance distances - for example, powerlines can swing in the wind or sag in the heat.
Before you start building
Before starting work, you will need to find out:
- the type of powerlines near the construction site, for example aerial or underground, high or low voltage
- how far overhead powerlines could swing or sag in windy or hot conditions
- the location of the building and the powerlines to allow enough space for people to work safely, including for scaffolding, future structures and where trees will be planted
- if powerlines need to be moved, so you can finalise the cost with the electricity network operator before you start building
- if scaffolding is to be erected, to allow for the scaffold’s width so that you meet safe clearance distances - Working safely near powerlines
- what approvals and permits are needed from the network operator and the Office of the Technical Regulator.
The electricity network operator , SA Power Networks or ElectraNet can advise on the sag and swing of transmission powerlines.
Fences with a height of two metres or less are exempt from compliance with minimum clearance distances. However, they must not restrict safe access to powerlines for repair and maintenance and must include gates to allow for truck access to the powerline.
Locating a swimming pool under any powerline is not recommended.
Safe clearance distances
The minimum safe distances between buildings and powerlines are set out in the Electricity (General) Regulations 2012. These distances are legal requirements that must be maintained at all times.
The clearance distance, and how it is measured, depends on whether the powerline is:
- a transmission powerline - 132 kV or higher powerline
- an aerial distribution powerline - 66 kV or lower powerline
- an underground powerline.
Clearance distances for transmission powerlines – 132 kV or higher
The minimum safety clearance distance for transmission powerlines is measured from the centre line and on each side of the powerline.
| Voltage of the transmission powerline | Minimum horizontal clearance distance |
|---|---|
| 275,000 V (275 kV) | 25 metres |
| 132,000 V (132 kV) Excluding single pole lines | 20 metres |
| 132,000 V (132 kV) Single pole lines | 15 metres |
Clearance distances for aerial distribution powerlines – 66 kV or lower powerline
The minimum safety clearance distances depend on:
- the voltage
- whether the conductor (powerline wire) is bare or insulated
- the maximum swing or sag of the line due to wind, temperature and the distance between poles
- type of building or structure.
Clearance distances are measured from the point of maximum swing or sag of the powerlines. SA Power Networks can advise on voltage and the maximum swing or sag.
| Voltage | Up to and including 1 kV | Insulated above 1 kV | Above 1 kV up to and including 33 kV | 66 kV | ||
|---|---|---|---|---|---|---|
| Conductor type | Insulated | Bare | Insulated with earthed screen | Insulated without earthed screen | Bare or covered | Bare |
| Dimension A | 2.7 m | 3.7m | 2.7 m | 3.7 m | 5.5 m | 6.7m |
| Dimension B | 0.1 m | 2.7m | 2.7 m | 2.7 m | 4.7 m | 5.5m |
| Dimension C | 0.1 m | 1.5m | 1.5 m | 1.5 m | 3.1 m | 5.5m |
| Dimension D | 0.1 m | 0.6m | 0.1 m | 0.6 m | 2.5 m | 4.5m |
Dimension A: Vertically above parts of a building or structure normally accessible to people – for example, balconies, terraces, walkways, bridges and scaffolds.
Dimension B: Vertically above parts of a building or structure not normally accessible to people but where people could stand – for example, roofs with a slope of less than 45 degrees, parapets wider than 0.1 metre, pergolas and carports.
Dimension C: Horizontally from parts of a building or structure for both normally accessible to people or where people could stand such as parts of buildings in A and B.
Dimension D: In any direction from those parts of a building or structure not normally accessed by people.
Clearance distances for underground powerlines
You must contact the electricity network operator to find out the exact location and the type of underground powerline before you start building.
If an underground powerline must be relocated to allow for the construction, the costs must be negotiated and finalised with the electricity network operator, usually SA Power Networks, before work begins.
Safe access to an electrical service pillar or pit - which supplies your property - must be available. You cannot build or place anything over or too close to it, including structures such as garages, retaining walls or moss rocks.
| Voltage of the underground line | Clearance distance |
|---|---|
| 33,000 V or less | 2.0 metres |
| 66,000 V to 275,000 V | 3.0 metres |
Permission to build inside the safe clearance zone
The Technical Regulator can approve buildings and structures within the clearance distance in limited circumstances.
Easements for powerlines
An easement allows legal access or use of your property for a specific purpose. If there is a powerline on your property, the electricity network operator typically:
- has the authority to inspect a powerline and take action to prevent an electrical hazard
- could have legal access to maintain the powerline
A statutory easement might not be identified on your certificate of title.
Digging or excavating near stobie poles
Digging near stobie poles and other electrical infrastructure could put you and the surrounding property at risk. You could contact underground cables or de-stabilise the pole causing it to fall over or start fires.
Legal requirements
You must have written permission from the electrical network operator if you intend to dig deeper than 30 cm within 3 metres of a stobie pole
The ground level can’t be raised directly under powerlines if it means the legal clearances can’t be met.
Planning approvals and powerlines
All development applications must include a statement under the Electricity Act confirming that the development plan complies with legal clearance requirements.
A planning and building approval does not mean that the building plan complies with the minimum clearance requirements prescribed by the Regulations.
Contact the Office of the Technical Regulator before submitting your development application if you are unsure.
