Part J6 Artificial lighting and power

See comments for Deemed-to-Satisfy Provisions of J0.0.

J6.2, J6.3, and J6.5(a)(ii) do not apply to Class 8 electricity network substations. The safety of workers requires manual lighting controls for inspection and maintenance activities of hazardous high voltage equipment.

There are two approaches available for the sole-occupancy units of residential buildings in J6.2(a)(i). They are a lamp power density approach or an illumination power density approach. The former is simpler while the latter provides considerably more flexibility for a dwelling with sophisticated lighting control systems. 5 W/m² for inside a dwelling is the criterion in both approaches.

Lamp power density is the simpler means of setting energy consumption at an efficient level for sole-occupancy units of Class 2 buildings or a Class 4 part of a building. It is a defined term and is calculated by adding the maximum power ratings of all the permanently wired lamps in a space and dividing this sum by the area of the space. With this approach there are no concessions for using timers, motion detectors or other control devices.

If the illumination power density approach is used the 5 W/m² can be increased by dividing it by the illumination power density adjustment factor in Table 6.2b where applicable. This more complex approach has been included as an increasing number of dwellings are using sophisticated control systems in order to reduce their energy consumption.

Lamps plugged into general purpose socket outlets are excluded through the definition of lamp power density and illumination power density because of the difficulty in regulating such portable appliances.

When illumination power density and one or more control devices are used, the adjustment factor is only applied to the space(s) served by the control device. The adjusted allowance for this space is then combined with the allowances for the remaining spaces using an area weighted average, which subsequently increases the allowance provided in J6.2(a)(i)(A) or (B).

The area of the space refers to the area the lights serve. This could be considered a single room, open plan space, verandah, balcony or the like, or the total area of all these spaces.

To comply with J6.2(a)(i), the design lamp power density or design illumination power density must be less than or equal to the allowance. Trading of allowances between J6.2(a)(i)(A) and (B) is not permitted.

J6.2(a)(i)(B) includes outdoor living spaces such as verandahs, balconies, patios, alfresco spaces or the like that are attached to a sole-occupancy unit of a Class 2 building or Class 4 part of a building.

J6.2(a)(iii) requires the power of the proposed installation to be used and may mean the light fittings be specified or some other administrative condition be applied.

J6.2(a)(iv) requires the less efficient halogen lamps to be separately switched from fluorescent lamps. This is because the halogens may not be needed all the time but would have to be on if they were controlled by the same switch as the more efficient fluorescent.

J6.2(b) covers other building classifications. Requirements for these types of buildings are more detailed than the requirements for sole-occupancy units of Class 2 buildings or a Class 4 part, in order to cater for the greater range of applications.

Where lamp power density or illumination power density may be used for sole-occupancy units in Class 2 buildings or a Class 4 part of a building, only illumination power density (IPD) can be used to measure compliance for all other applications.

Lighting in non-residential commercial buildings is progressively moving towards the use of LED lamps for general lighting and for special lighting. At present other lamps are available, but because of the shift to LED lamps for general lighting, the illumination power density levels in Part J6 reflect this newer technology. The aggregated design illumination load is the maximum load in the lamp’s operational cycle.

J6.2(b)(i) describes the process for determining the illumination power allowance for artificial lighting, however it does not apply to the sole-occupancy units of a Class 2 building or a Class 4 part of a building.

The maximum values in Table J6.2a have been derived on the basis of a lighting design complying with the recommendations of AS 1680 for the nature of the task, including an allowance for a safety margin in design and the physical limitation of placing a discrete number of fittings in a uniform array. The maintained illuminance will be designed to suit the use of the area and again is based on the illuminance levels in AS 1680 or an equivalent document from an overseas standards organisation. However, the levels are not being controlled by Section J of the BCA; only the power allowance for achieving the desired illuminance.

The following table shows how some of the illumination power density values correspond to the lighting levels of AS 1680.

The allowance is for the power supply to the lighting.

The values have been generally set at a level that can be achieved with reasonable surface reflectances, direct (rather than indirect) lighting, and low loss control gear. The use of the space has also been taken into account. However, Performance Solutions, developed to the satisfaction of the local building control authority, can be used for spaces that have complex or specific lighting needs. AS 1680.1 includes scenarios of where it may be appropriate for higher illumination levels. Where higher illumination levels can be justified to the local building control authority, a Performance Solution based on the notes to Table J6.2a could be developed. Alternatively, energy saved by more efficient building services or through the installation of on-site renewable energy systems may also be used to increase the allowances for lighting, again subject to the approval of the local building control authority.

There are two levels for offices. General open areas that are lit to more than 200 lx may use 4.5 W/m². For offices lit to less than 200 lx, where task lighting is intended to supplement the general lighting, the maximum for the general lighting is only 2.5 W/m².

The table provides values based on the illuminance level.

It is recognised that there are many variables in lighting that limit the ability to achieve the maximum illumination power density. One is the size of the room and so note 3 of Table J6.2a explains how the illumination power density may be increased for small rooms. A further series of adjustment factors have been included in Table J6.2b and Table J6.2c that allow credit for additional energy control devices or to allow the use of high Colour Rendition Lights.

The adjustment factors are applied to the maximum illumination power density in Table J6.2a. This means that if a designer chooses to use a less efficient light source or luminaire, compliance can be achieved by the use of a supplementary control device such as an occupancy sensor or photoelectric device.

Occupancy sensors represent an efficient way of tailoring the lighting to the usage of the space. The fewer lights that are controlled by an individual sensor the greater the energy saved, however, there is less cost saving on the energy to offset the cost of the sensor. Therefore, there is a graduated scale of adjustment factors for the area of lights controlled.

For lecture theatres, auditoria and large spaces of transient usage, the contribution of detectors should be assessed using a Performance Solution rather than the Deemed-to-Satisfy Provisions.

The lighting control requirements are directed at enabling occupants to save energy on lighting and power when the space is not occupied or the service is not needed.

J6.3(a) requires each room or space to be individually switched or controlled. This is to ensure that when lighting to a small area is required, lighting to a larger area is not also activated.

J6.3(b) requires that an occupant activated device be installed in a sole-occupancy unit of a Class 3 building, based on the likelihood that guests may not switch off the power when leaving the room.

This power includes the lighting, air-conditioning, exhaust fans and bathroom heating when the room is not occupied. The control device is not detailed so the requirements can be met by various systems such as a security device like a room key slot at the door, a motion detector, or any device or system that can monitor the occupancy of the unit. For the purpose of applying this provision, occupancy should be taken as the physical presence of people in the room rather than having someone registered or checked into the unit.

J6.3(c) requires lighting to be locally switched from a position that is visible in the room or in an adjacent room. If the controls are in an adjacent room, then the lighting that is controlled must be visible from the switching position. This is to reduce the possibility of lighting being left on in unoccupied areas because it cannot be seen.

Most buildings are required to have local control of the lighting in manageable blocks. This is to avoid the situation where a large area of lighting has to be switched on when only a small area is required, simply because there is no subdivision of the switching area. Buildings with lighting that is likely to be totally on or totally off, such as a theatre or swimming pool, are exempted.

J6.3(d) requires a non-residential building or storey (i.e. other than a sole-occupancy unit in a Class 2 or 3 and Class 4 part) over 250 m² to have controls to prevent most of the lighting being left on 24 hours a day. This can be a time switch or occupancy sensor. The time switching has to comply with Specification J6. Simple manual override switches or bypass switches are not allowed as they give the ability to permanently disable the control. The time switch control does not preclude the need for local control.

J6.3(e) applies to only certain buildings and specifically to switching the lights near windows.

J6.3(f) requires the artificial lighting in fire-isolated stairways, passageways and ramps to be controlled by motion detectors. Note that this does not apply to emergency lighting required in accordance with Part E4.

These are additional control requirements for decorative and display lighting as distinct from those for other artificial lighting in a space.

It is not practical to apply illumination power density to external lighting in the same way as it has been applied to internal lighting because it is difficult to define the relevant area for all situations. The requirements are therefore aimed at ensuring efficient light sources are used or that the lighting only operates when it is required.

All external lighting must be controlled by either a daylight sensor or time switch.

A time switch is required for boiling water and chilled water storage units that continually maintain water at temperature because they can waste energy overnight and during weekends. This clause is not intended to apply to units that heat or chill water as it is being drawn off.

The intent of this provision is to ensure lifts that are expected to have high frequency usage are the most efficient.

A lower energy rating has been allowed for dedicated goods lifts, i.e. a lift used for carrying goods or materials and in which only the attendant and the persons required to load and unload are intended (or permitted) to travel. This is in recognition that these lifts have different requirements than passenger lifts.

The intent of the provisions is to ensure that escalators and moving walkways are configured to save energy when not in use.