Building safely near powerlines
Electricity can be extremely dangerous. To protect people and property, safe clearance distances between buildings and powerlines have been established in the Electricity (General) Regulations 2012.
Dangers of buildings near powerlines
Electricity can be extremely dangerous to people and can cause serious injuries or even death.
When building or extending, always ensure there is enough space between the building and the powerlines to minimise the risk of electric shock, fire, power cuts or damage to the property or powerlines now and in the future – see Safe clearance distances.
Electricity can flash over a gap. A person can be some distance from a powerline and still be in danger of receiving an electric shock or severe burns.
In addition, aerial lines swing in wind and sag due to heat – this movement must also be accounted for in any clearance distance. To ensure safe approach limits are maintained when working near powerlines, take the movement of the lines into account.
Before you begin building near powerlines
Before starting work on your building you need to know and consider:
- the type of powerlines near the construction site – eg aerial, underground, high or low voltage.
- the amount of swing or sag of overhead powerlines – the electricity network operator SA Power Networks (formerly ETSA Utilities) or Electranet can provide this information.
- the location of the building in relation to the powerline – allow enough space for a safe work environment, future structures and scaffolds, trees and so on.
- any approvals or permits from the electricity network operator or approvals you may need to obtain from the Office of the Technical Regulator
- the possible need for relocating powerlines – the cost of altering the powerlines should be negotiated and finalised with the electricity network operator before the start of construction
- scaffolding - in designing the building you should also allow for the width of any scaffold you may need to erect. This is to ensure that the scaffold may be positioned so that legal clearance distances are met. You should also consider future needs for erecting a scaffold, see Working safely near powerlines.
Safe clearance distances
The minimum safety clearance 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.
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.
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.
See Identifying powerlines for advice about identifying powerlines.
Clearance distances for transmission powerlines – 132 kV or higher
When building near high voltage transmission powerlines (132 kV or higher), the minimum safety clearance distance is measured from the centreline of the transmission powerline 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
For aerial distribution lines (66 kV or lower), the minimum safety clearance distances depend on:
- the voltage
- whether the conductor (powerline wire) is bare or insulated
- swing or sag of the powerline due to wind, temperature and distance between poles
- type of building or structure.
The electricity network operator in South Australia, SA Power Networks can provide information on the voltage and the maximum amount of swing or sag of the powerline.
Clearance distances are measured from the point of maximum swing or sag of the powerlines.
|Voltage||Up to and including 1 kV||Insulated above 1 kV||Above 1 kV |
up to and including 33 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 - eg balconies, terraces, walkways, bridges and scaffolds.
Dimension B: Vertically above parts of a building or structure not normally accessible to people but on which people can stand - eg 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 normally accessible to people or not normally accessible to people but on which they can 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 accessible to people.
Clearance distances for underground powerlines
Before starting construction in areas with underground powerlines, you must contact the electricity network operator to find out the exact location and the type of the underground powerline.
Minimum safety clearance distances must be met when building close to underground powerlines.
Where it is necessary to relocate an underground powerline to allow for the construction, the relocation costs must be negotiated and finalised with the electricity network operator, usually SA Power Networks, before the start of construction.
If your property is supplied from an electrical service pillar or pit, you must not construct or place anything over or too close to it. This includes structures such as garages, retaining walls or moss rocks as they may restrict safe access to the service pit. Contact SA Power Networks for more information.
|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 has powers to approve buildings and structures within the clearance distance, in limited circumstances where it is safe to do so. Contact the Office of the Technical Regulator for details.
Easements for powerlines
An easement is a legal privilege to use another person's property for a specified purpose. In relation to powerlines, this means that the electricity network provider has legal permission to access and maintain the infrastructure.
There are different kinds of easements on properties containing powerlines. If there is a powerline on your property, the electricity network operator may have a statutory easement to access and maintain the powerline. Even if there is no statutory easement on a property, the electricity network operator has the authority, at any reasonable time, to inspect the powerline and take action to prevent or minimise an electrical hazard.
Digging or excavating near stobie poles
Digging near stobie poles and other electrical infrastructure could present risks to your safety and the surrounding property. You could contact underground cables or de-stabilise the pole causing it to fall over, start fires or increase the risk of contact with people.
Before digging, call 1100 or visit the Dial before you Dig website.
If you intend to dig deeper than 30 cm within three metres of a stobie pole, you are legally required to obtain a written permission from the electricity network operator.
It is also prohibited to raise the ground level directly under powerlines if it reduces the ground clearance to less than that prescribed by the regulations.
Planning approvals and powerlines
A planning and building approval issued by a council does not mean that the building plan complies with the minimum clearance requirements prescribed by the regulations.
All development applications submitted to councils must include a signed Electricity Act Declaration Form acknowledging that the development plan complies with prescribed clearance requirements.