There are two types of solar systems available, which may decide whether you need to apply for a building consent when installing a solar panel system.

What is the difference between the solar systems?
- Solar photovoltaic panels

Solar photovoltaic systems, also known as solar PV, are made up of panels of solar cells. Solar PV gets its name from the process of converting light (photons) on the panels into electricity (voltage) via a solar inverter. The electricity produced can be used to operate any electrical items linked to the system.

Solar PV panels differ from solar hot water systems in that they do not pass water through them. This makes them lighter placing minimal additional loads onto the roof structure.

- Solar hot water

The name says it – a solar hot water system heats up water.

Solar hot water systems operate with a collector that uses the sun’s thermal energy to heat the water going through, and a storage tank. Due to liquid running through the collectors, these systems place additional load on the roof structure.

There are different systems available depending on the type of collector and circulation system as follows:

  • Direct systems circulate water through solar collectors where it is heated by the sun. The heated water is then stored in a tank, sent to a tank-less water heater, or used directly.
  • Closed-loop or indirect systems use a non-freezing liquid to transfer heat from the sun to water in a storage tank. The sun's thermal energy heats the fluid in the solar collectors, which then passes through a heat exchanger in the storage tank, transferring the heat to the water. The non-freezing fluid cycles back to the collectors.

These systems can be either active/force-circulation, or passive.

Do I need a building consent for solar panels?
- Solar photovoltaic panels

Generally speaking energy work does not require a building consent – refer to section 43 of the Building Act 2004.

Therefore if you are installing solar PV a building consent is not required. If however the photovoltaic panels also form the roof cladding, for example “Solartile” from Monier, a building consent will be required.

Regardless of whether or not a building consent is required for a solar PV system, all work must comply with the NZ Building Code.

- Solar hot water

You will need to obtain a building consent for a solar hot water system. This is to ensure correct installation due to safety issues associated with water heating devices.

All solar hot water installations require a certifying plumber licensed under the Plumbers, Gasfitters, Drainlayers Act 2006 to install the system.

To apply for a building consent for a solar hot water system you will need to provide the following:

  • Completed building consent application form
  • A copy of the current property title
  • Product specifications, including attachment details
  • A floor plan
  • Elevations of the dwelling
  • A plumbing schematic
  • Hot water cylinder specifications, including details of the safe tray