DELITOS CONTRA LOS RECURSOS NATURALES

For operational rating of commercial buildings, the most widely used tool in Australia is the National Australian Built Environment Rating System (NABERS). The NABERS scheme is administered by the NSW Office of Environment and Heritage (OEH), and there are several tools, such as NABERS office, NABERS retail, etc., which allow direct comparison against similar buildings, with similar intensity and hours of operation. To determine an energy benchmark, this rating system compares the annual energy consumption data against averages developed for different climatic areas in Australia. The benchmark values of energy intensity can be calculated from the NABERS reverse calculator (NABERS, 2015). The other important benchmarking tool in the Australian context is Green Star. Green Star is currently available for Design and As-built ratings. Green Star Performance (GBCA, 2014), which uses operational data, was launched as a pilot tool in 2013, and at the time of writing (May 2015) had seven completed ratings.

The NABERS rating scheme is a performance-based rating scheme, which has been operating in Australia since 1999. It was known initially as the Australian Building Greenhouse Rating (ABGR) scheme, and was primarily focussed on office building energy use in NSW. Over the period to 2009, the scheme expanded to include other states, and other measures of environmental performance including indoor air quality, waste and water. In 2009, the ABGR was incorporated

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into NABERS as NABERS Energy for Offices. NABERS ratings are available for three rating scopes, base building, tenancy, and whole building. Bannister (2012b) identified the following as key aspects of the NABERS ratings:

1. The ratings are based on operation consumption (12 months of actual data);

2. The ratings are normalised for unavoidable operational factors, such as hours of occupancy and climate, but not building specific efficiency factors;

3. The rating scale is based on a median building achieving a rating of 2.5 stars;

4. The base building/tenancy split means ‘the base building rating can be used as a generic measure of efficiency in procurement.’

As part of the NABERS process a building owner may enter into a commitment agreement; a commitment to design, build and commission or upgrade a building to a certain rating greater than 4 star. A commitment agreement allows the building owner to advertise the NABERS rating from the outset of the project, prior to a 12 months operational data being available. The rating is reviewed when the performance data is available. At the time of writing (May 2015) there were 154 commitment agreements awaiting performance rating. Commitment agreements require BPS of the development, in accordance with the simulation protocol discussed in Section 2.6.4.

Until the end of 2010 NABERS was a voluntary rating scheme; however it had a high level of adoption reaching over 50% of the national office market in 2009/10 (Bannister, 2012b). A key driver for voluntary adoption was the inclusion of NABERS base building rating requirements into government leases. By 2009, it was a requirement of all state and federal governments (except Tasmania) that leased buildings achieved a minimum 4.5 star NABERS rating. In 2010 the Building Energy Efficiency Disclosure Act was introduced, which mandated disclosure of a building’s NABERS ratings in certain circumstances. Building owners are required to disclose a Building Energy Efficiency Certificate (BEEC) for sale and lease transactions of more than 2,000 m2 of NLA. A BEEC comprise a NABERS rating, tenancy lighting assessment, and general energy efficiency guidance for the building. Mandatory disclosure is designed to improve access to information about energy efficiency of buildings and encourage potential tenants or owners to select more efficient buildings, creating pressure for building owners to improve efficiency.

Commercial building disclosure legislation has made the NABERS scheme increasingly important to businesses. The legislation is a significant driver of NABERS energy rating uptake. At the time of writing, 70% of all NABERS ratings were associated with a BEEC. Figure 2-13 shows the total

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NLA of office building rated under the NABERS energy scheme, and the area weighted average rating. It can be seen that since 2005 there has been a greater than 500% increase in floor area rated under the scheme. There has also been a steady increase in the area weighted average rating. In 2013 72% of the national office market had been rated under the NABERS scheme at some point in time – 1984 individual buildings (IPD, 2013). At the time of writing (May 2015), there were 1324 current office energy ratings; 189 tenancy, 261 whole building, and 874 base building ratings.

Figure 2-13 Total NLA of offices rated under the NABERS energy for offices scheme. Also shown is the area weighted average rating for the rated stock. Modified from IPD (2013).

As of December 2013, the area weighted average NABERS rating was 4.1 stars (IPD, 2013). The distribution of NABERS energy office ratings by NLA is presented in

Figure 2-14. The distribution is centred on 4.5 stars, with a long tail to lower ratings.

IPD (2013) examined the investment performance of NABERS energy-rated office assets. In general, it was found that more highly rated offices (4.5 – 6 stars) returned substantially higher capital growth, and higher total return. Income return was essentially unaffected by star rating (0.1% higher for higher ratings); Capital return was 3.1% for high ratings, 2.4% for all offices, and 1.5% for 0-4 star offices, based on a sample of 591 assets from the IPD database. Higher rated buildings also had lower vacancy rates, higher rents, and slightly longer lease terms. This re- enforces the findings from Section 2.2.

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Figure 2-14 NABERS energy rated office NLA by star rating (IPD, 2013).