If you’re doing any work where you, as the contractor, are designing the lighting system of a commercial or residential installation, then you must comply with the BCA. There’s no more placing lights around a building ‘willy-nilly’ as there are now a number of energy efficiency requirements to which you must adhere.
Simply put, these new requirements are designed to provide a 6-star energy rating for new residential buildings, improved energy efficiency requirements for hot water and lighting systems in new residential buildings, and increased energy efficiency requirements for all new commercial buildings.
Incidentally, these provisions have been in effect since May 2010 in South Australia and the ACT. Queensland, Victoria, New South Wales, Western Australia and Northern Territory adopted them from May 2011.
Ultimately, the changes mean that wherever a planning permit is required for the construction of a new home or major renovation, the customer will require a Certificate of Occupancy. This certification will be determined at the commissioning phase by the local council’s building inspector, usually from the home’s lighting plans.
The provisions are mainly designed to affect hard-wired lighting but do extend to a number of other areas where electrical power is used. Free-standing lighting connected by the usual plug‑into-a-wall-socket, bathroom heater and light units and any fans, exhaust or ceiling, without lamps are exempt. As are decorative or display lighting which is switched on/off and controlled separately from normal lighting.
Following are a number of points to provide you a heads-up on just what is affected by these energy efficiency provisions.
Roof and ceiling construction
Where downlights are installed, there is usually a loss of insulation in those areas. An electrician must realise that this will limit the number of these devices allowed to be installed and he must be aware of the appropriate R-value of the insulation for compensation. The more downlights, the higher the rating of insulation required.
It’s important to note that insulation is not permitted to interfere with the safe and effective operation of a domestic service or fitting. Necessary clearances per the Wiring Rules or manufacturer’s instructions are to be followed when installing any devices within the ceiling.
Artificial lighting and power
Specifications have been set for the illumination power density (IPD) of artificial lighting, excluding heaters that emit light. This allowance is based on the power drawn by the system, not just on the capacity of the lamps. Tables are provided in the BCA to enable correct calculation of the IPD.
Specifically, the IPD must not exceed:
1. 5W/m2 in the interior of a house (Class 1 building).
2. 4W/m2 on a verandah or balcony of a house (attached to a Class 1 building).
3. 3W/m2 in the interior of a garage (Class 10 building).
These values can be exceeded if control devices, such as dimmers and lighting control systems, are used.
Allowances for lighting control
Any allowance given for the inclusion of lighting control systems is based on various adjustment factors. The ratings defined above are divided by the appropriate adjustment factor based on the type of control device and the percentage of area being controlled.
Apologies in advance for the calculations below, but it is important that you understand that lighting controls from the most basic to fully automated enable a far greater allowance as to the wattage per square metre than the three IPD values above:
1. The very basic adjustment factor is for a lighting timer in a corridor. Here the factor is 0.7 (e.g. 5÷0.7 = 7.14W/m2).
2. By moving to a motion detector (pardon the pun) there are various factors applicable depending on:
a) At least 75% of the area, or if the area being switched in one block is less than 200m2 and is controlled by one motion detector, at a minimum the allowance factor is 0.9 (eg. 5÷0.9 = 5.56W/m2).
b) Up to six lights are switched as one block by one motion detector, at a minimum the allowance is 0.7 (eg. 5÷0.7 = 7.14W/m2).
c) Up to two lights are switched as one block by one motion detector, at a minimum the allowance is 0.55 (eg. 5÷0.55 = 9.1W/m2).
3. A manual dimming system where lights are controlled by a rotary knob or a slider, and where not less than 75% of the area is controlled by such,
the allowance is 0.95 (eg. 5÷0.95 = 5.26W/m2).
4. A programmable dimming system where pre-selected scenes or levels are automatically altered by the time of day, a photo-electric cell or occupancy sensor and where not less than 75% of the area is controlled by such – the allowance is 0.85 (eg. 5÷0.85 = 5.88W/m2).
5. A dynamic dimming system where the lighting level is varied automatically by a photo-electric cell to either proportionally compensate for daylight availability or lumen depreciation of the lamps – the allowance is 0.9 for fluorescent lamps (eg. 5÷0.9 = 5.56W/m2) or 0.8 for high pressure discharge lights (eg. 5÷0.8 = 6.25W/m2).
6. A fixed dimming system where lights are controlled to a level and that level cannot be adjusted by the user, and 75% minimum of the area is controlled by such to reduce overall lighting level and power consumption of the building – the allowance is the percentage of power to which the dimmer is set divided by 0.95.
7. A combined daylight sensor and dynamic control device where:
a) Lights within the space are adjacent to windows, where the distance from the window equals the depth of the floor to window head height – the allowance is 0.5 (eg. 5÷0.5 = 10W/m2).
b) Lights within the space adjacent to roof lights – allowance is 0.6 (eg. 5÷0.6 = 8.33W/m2).
Note: Bear in mind that these allowances in the combined scenario are not available for tungsten halogen or other incandescent sources.
All ballasts for lamps must now be of the electronic type, with halogen and fluorescent lamps being required to be switched separately. This will incur limitations on the use of inefficient fluorescent and halogen lamps.
Switch locations and the areas of control are to be taken into consideration when designing an installation. This requirement will effectively ensure that where a space is not occupied or the service is not needed, there will be an energy saving in regard to light and power usage. Any switching is not to activate larger areas where only small areas need lighting.
Building perimeter lighting
Lighting around the perimeter of a building needs to be controlled by a daylight sensor, timer or motion detector.
Facilities for energy monitoring
Most commercial buildings, depending on their size, will be required to have a facility to record and monitor energy consumption.
I can already hear people saying “You need to be Einstein!” and other comments as to the usual over-governing by our government bodies, but it is important that all installers take this as an opportunity to provide more value to their customers and to the cleaner and greener strategies that should now be our focus.
Inefficient systems will be a thing of the past with these provisions now mandated. The use of control systems will limit the unnecessary wastage of energy and ensure that only the areas to be serviced by electrical lighting are in use only when occupied. No matter what the job you get asked to quote on, all electricians will need to be aware of these provisions as the use of lighting controls will substantially increase the value to the customer. A grand opportunity indeed!