Part J9 Energy monitoring and on-site distributed energy resources

Where a solution is proposed to comply with the Deemed-to-Satisfy Provisions, J2D1 clarifies how compliance with Parts J2 to J9 achieves compliance with J1P1 to J1P4.

Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A2G2(3) and A2G4(3) as applicable. (See commentary on Part A2).

The Deemed-to-Satisfy Provisions, including those related to house energy rating software, described are limited to the most common forms of construction and the simplest forms of buildings. It is expected that the more innovative construction techniques and the more complex buildings will be designed and assessed using a performance approach.

A major consideration in developing the measures was the likelihood of a building being heated or cooled by an air- conditioning system, and whether the Deemed-to-Satisfy Provisions should assume this to be the case, or only apply the provisions if a heating or cooling system is installed. It is recognised that most Class 3, 5, 6 and 9 buildings and some Class 7 and 8 buildings are heated or cooled, and this is the basis of the provisions. Consideration was also given to the fact that although the first owner may be prepared to ‘manage’ their building in the appropriate manner, the next owner or tenant may not, and instead may install air-conditioning.

Because of the performance-based structure of the NCC, a Performance Solution may be proposed instead of the Deemed-to-Satisfy Provisions.

Part J9 does not apply to private dwellings, i.e. Class 1 buildings, therefore it is also not applied to the sole-occupancy units of Class 2 buildings, or Class 4 parts of buildings.

The access for maintenance and power monitoring procedures for Class 8 electricity network substations have inherent and critical characteristics that either supersede or vary from the procedures adopted and applied to other buildings. Therefore, Part J9 does not apply.

In order for maintenance personnel to ensure that active energy efficiency items and systems continue to operate at their required level of performance, they need to know the energy usage of the building over time and also the usage of individual services in a large building. To facilitate this outcome, the data collected by energy meters is to be made readily accessible to personnel without requiring the physical inspection of meters. The data must be transmitted to a communications platform (e.g. a computer) in a format (e.g. a .csv file) that allows for its analysis by maintenance personnel.

The intent of J9D4 is to ensure that the building is ready for the installation of EV charging equipment, should this be desired by a future user of the building.

J9D4(1) mandates that, subject to J9D4(2), carparks associated with Class 2, 3, 5, 6, 7b, 8, and 9 buildings must be equipped with electrical distribution boards that are solely dedicated to EV charging. The reason this clause states that the number of required distribution boards is “subject to J9D4(2)” is to indicate that the number of boards relates to the number of car spaces required to be ready for EV charging equipment. For example, as 10% of car spaces attached to a Class 5 building are required to be EV ready, the carpark associated with the building would need to have at least 100 car spaces on a storey before requiring one EV dedicated distribution board. Additionally, they must be clearly labelled to indicate their specific use for EV charging equipment.
Note: For the purposes of J9D4(1), a carpark is associated with another building if the carpark is on the same site as the building and is provided to serve that building. i.e., a carpark is considered associated with a building if it shares the same property location and is specifically intended to provide parking for the occupants or users of that building.

J9D4(2) has more requirements for these distribution boards. First, each board must be connected to a charging control system capable of managing and scheduling the EV charging based on the building's overall power consumption and needs. For carparks associated with a Class 2 building, the circuits must be capable of supporting an EV charger that delivers a minimum of 12 kWh from 11:00 pm to 7:00 am. Similarly, for Class 5 to 9 buildings, the circuits should support an EV charger delivering a minimum of 12 kWh between 9:00 am and 5:00 pm. The specified hours match the times when EVs are most likely to require charging for each building type. In Class 3 buildings the capacity should be significantly higher, with each circuit supporting an EV charger needing to deliver a minimum of 48 kWh from 11:00 pm to 7:00 am. The higher capacity matches the anticipated needs of drivers who are likely to have travelled longer distances to get to a Class 3 building.

Beyond current requirements, the provision also looks to the future. While there is no requirement to install EV chargers from the outset, the electrical boards are to be designed to facilitate subsequent installation of 7 kW (32 A) type 2 EV chargers. The percentage of carpark spaces that must be capable of supporting these future installations varies depending on the class of the associated building. Additionally, the boards must contain enough room—specifically, a width of at least 36 mm of DIN rail for each outgoing circuit—for future installation of individual sub-circuit electricity metering of the electricity use of EV charging equipment. This space is to be labelled to denote its purpose.

Limitations and special cases

The provision exempts stand-alone Class 7a buildings from these requirements. This is due to the typically lighter electrical loads of these structures, making the addition of EV charging facilities excessive and unwarranted. However, all other carparks that exist in connection with specific buildings or groups of buildings should adhere to these requirements.

J9D5 addresses the infrastructure required for future installation of solar photovoltaic and battery systems. The provision encourages sustainable energy solutions by mandating the necessary setup on the main electrical switchboard and roof area.

Main Electrical Switchboard

J9D5(1) stipulates:

• The main electrical switchboard should contain at least two empty three-phase circuit breaker slots and four DIN rail spaces, labelled for use by solar photovoltaic and battery systems.
• The switchboard must be sized to accommodate solar panels that could cover at least 20% of the building's roof area.

Buildings with solar panels covering at least 20% of the roof are exempt from the requirements of J9D5(1)(a)(i) and (b). Buildings with installed battery systems are exempt from the requirements of J9D5(1)(a)(ii) and (b).

Roof Area Requirements

J9D5(2) addresses roof area conditions with at least 20% of the roof area should be kept free for installing solar photovoltaic panels.
Buildings with already installed solar panels covering at least 20% of the roof, or those with 100% shading for more than 70% of daylight hours, or special use cases like terraces and roof gardens, are exempt. These exemptions are intended to cover buildings where the use of rooftop solar panels will be ineffective or impractical.