Embracing the NCC and Wiring Rules


The National Construction Code and the Wiring Rules should go hand-in-hand, and new business will emerge. Gary Busbridge spells it out.

wiringrulesAs I travel around this big country giving talks, there’s an unnatural quiet among audience members when I ask whether anyone has looked at the Building Code of Australia.

A while ago I investigated and discovered it has been mandatory since May 2011 for electricians engaged in residential work to follow the code – as it is for chippies, brickies or plumbers.

The reason I keep mentioning the subject is not only that it’s mandatory but also that it presents a great opportunity for your business in regard to energy efficiency.

You can tell customers how to improve energy efficiency and increase the value of their home just by having some smart and not-so-smart electrical devices fitted.

Let’s start by explaining the code and its goals.

This three-volume set of books has been renamed as the National Construction Code (NCC). Volume 1 is for commercial construction, Volume 2 for residential construction and Volume 3 for plumbing.

The main goal is to maintain a consistent approach to health, safety, amenity and sustainability at a national level. Energy efficiency is a key to sustainability and is aimed at reducing greenhouse gas effects. The efficiency of the design is star rated from one to 10. New homes are generally supposed to be designed to a six-star rating.

How is this measured? Well, the software program NatHERS is used by an accredited assessor to determine the number of stars for a dwelling. It is based on specific climate zones plus location, layout, construction type, window orientation, shading, local wind direction, occupancy and dwelling dimensions.

A zero star rating means there is a shell of a house that does nothing to protect against the discomfort of weather extremes, much like the ‘swag’ example I use in my talks. A 10-star rated home is unlikely to need any artificial cooling or heating. This scale is based on maximum energy consumption per unit area (MJ/m2) loads.

It’s not particularly what you, an electrician, need to know about, but a little explanation can give some idea of what the assessors provide.

The program sets the climate zones based on postcodes, for example, Adelaide is climate zone 16, Port Hedland is climate zone 2 and Mascot is climate zone 56. By using these climate zones and the amount of energy consumed to heat and cool a home, a star rating can be assigned as follows:

A 0.5 star home uses:

  • 584MJ/m2 in Adelaide;
  • 643MJ/m2 in Port Hedland; and
  • 352MJ/m2 in Mascot.

A six-star home uses:

  • 96MJ/m2 in Adelaide;
  • 215MJ/m2, in Port Hedland; and
  • 51MJ/m2 in Mascot.

A 10-star home uses:

  • 3MJ/m2 in Adelaide;
  • 62MJ/m2 in Port Hedland; and
  • 5MJ/m2 in Mascot.

To put it in context, houses built around 1990 average about one star, and before 2003 less than 1% of houses achieved six stars.

Fortunately all that is directed at the home designer, so this is where the electrician comes in.

During the life of a building numerous hot water systems, lights and appliances are installed and maintained, and their energy consumption is not included in the rating program.

Household energy use can be attributed to heating and cooling (about 40%), water heating (about 20%), appliances including refrigerators and cookers (about 30%) and lighting (about 6%). If some of these were dealt with appropriately there would be huge savings for your customers.

The specifics of the energy efficiency measures are listed in the NCC, but the following is a guide to what is required.

With heating and cooling it is as simple as using a system that is zoned, or space heating and cooling only in the rooms that require it. Fans provide a cost-effective means of cooling, and evaporative coolers are great cost savers in areas of low humidity.

Lighting costs can be reduced by taking into account various factors listed in the NCC and designing the lighting in an efficient manner.

Maximising the use of natural light helps in a big way. The use of control devices such as dimmers, timers, motion sensors and daylight sensors will ensure that the design is most efficient. However, you must consider issues such as lamp technologies, safety requirements and life-cycle costs to balance this out.

Increasingly, energy usage can be attributed to home entertainment and home office equipment because of the standby power mode. We used to make do with an on/off switch, but now everything needs to be ready at our beck and call. Standby power could account for up to 10% of a home’s energy consumption.

The ultimate way to cut energy consumption is to automate or remotely control the on/off modes of devices and the adjustment of operating settings. This automation can be teamed up with smart phones and the like to further improve energy efficiency.

Another way of boosting efficiency would be to employ solar power systems, or even wind generation.

Then, to top it off, you could install energy monitoring systems – from a simple monitor for tracking electricity use in the entire home, to complex systems that cover electricity, gas and water.

Your customers will welcome the opportunity to see where energy is being used, then change their habits to reduce consumption.

Whether working on a new installation or adding to an existing one, an electrician is well placed to advise the customer about an energy-efficient option, to the benefit of both. The electrician has created an ‘up-sell’ and the customer is rewarded by lower energy costs.

In conclusion there’s some good news: the NCC volumes will be offered free of charge in 2015 as a download, eliminating the excuse that the publications are costly and difficult to acquire.

The energy efficiency section is on its own, and not hard to understand. So get yourself a copy and study the provisions. It may be as important to you as the Wiring Rules.

About Gary Busbridge

Gary Busbridge

Gary Busbridge has been with Clipsal for more than 33 years. Since 1997, he has been involved with Standards Australia and has held memberships in several Standards committees.

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