Shoot for the stars to power the towers

Demand is rising for green office blocks as owners and tenants seek to cut costs. 

 The national green star rating system for office buildings is having one important side effect - those that are energy efficient are becoming much more valuable than those that are not.

An awareness of climate change has driven office-block tenants to want to reduce greenhouse emissions, but the biggest influence appears to have been cost. By upgrading a typical 20,000-square-metre office space in central Sydney from a two-star to a four-star rating, the owners would save enough energy to power 180 average houses.

The National Australian Built Environment Rating System (NABERS), which complement the green star ratings, are moving towards mandatory disclosure of energy performance from November.

''The early adopters who have been rating their buildings with NABERS for years have shown that ratings lead to better environmental performance and therefore lower costs for both building owners and tenants,'' says Matthew Clark, the director of water and energy programs at the NSW Department of Environment, Climate Change and Water, which administers the scheme. ''The higher the NABERS rating, the more attractive your building is to the market.''

Last financial year, the number of city office buildings seeking a rating rose 260 per cent, while the number of people trained to assess a building's energy performance in NSW is now 695, up from 261 three years ago....