Energy ratings given a clearer ruling

The energy star ratings set for Australia's commercial property sector will twinkle more clearly after a long-awaited ruling by the body administering the scheme.

After lengthy public consultation, the National Australian Built Environment Rating System has ruled it will recognise low-emissions energy supplied off-site to boost a building's ratings.

The catch, though, is that it will also require that the NABERS Energy certificate disclose what the building's star rating would have been if the green energy had not been purchased.

The ruling has been closely watched by property owners, such as Investa Property Group. It had sought to capitalise on excess power it was generating from an advanced gas-fired tri-generation plant at its six star-rated The Ark building in North Sydney, to lift the rating on its building at 126 Philip Street, in Sydney's CBD.

"Some of the [co-generators] providers didn't want us to separately disclose on certificates how much the NABERS ratings would be without that purchase of co-gens," said Matthew Clark, the director of water and energy programs at the NSW Office of Environment and Heritage, which administers NABERS.

"It's about how much transparency we give to the market, and the question from some parties [was] that too much transparency might not be a good thing," he said.

Investa said it was not disappointed by the ruling.

"We anticipated this outcome," said Shaun Condon, Investa's head of environment and safety. "There was discussion around whether the rating should reflect the benefit provided by trigeneration electricity [but] we feel this approach is appropriate."

The ruling treats imports of low-emissions energy similarly to purchases of green power, a move that office owners can also use to lift a building's energy star rating. By disclosing how much the rating owed to the purchase of green energy the market can gauge the underlying environmental performance of the building itself. Mr Clark said such information was useful for tenants should the property change hands and a new owner begin sourcing energy from elsewhere.

The ruling should reinforce the validity of the NABERS scheme, said Stephen Hennessy, a director of consultants WT Sustainability.

"It is a robust system and it needs to continue to be recognised as a robust system," Mr Hennessy said.

Elsewhere, Craig Roussac, Investa's manager for sustainability, has resigned to develop and commercialise Investa's Pulse technology devised to provide daily energy performance to building operators. The company said it will "maintain an ongoing relationship" with Mr Roussac's new company.

Beck Dawson, previously Investa's Sustainability Manager, has been appointed head of the company's corporate sustainability.