Meridian Energy's $36 million headquarters on Wellington's waterfront has received a top rating for energy efficiency.
The four-storey office block, which was built in 2007, has been rated 5.5 stars out of 6 under new rating scheme NABERSNZ.
The scheme, which started in Australia, was introduced to New Zealand only in June and the Meridian building has received the highest star rating of the five buildings which have been assessed.
It costs building owners $2000-$5000 to be assessed under the NABERSNZ scheme but Green Building Council chief executive Alex Cutler said it was worth it.
"What it does is it gives you a huge amount of granular information about your building," Ms Cutler said.
"If you have commissioned it well and if you're running it well and you're paying attention to how your services are running, then your building will get a good rating."
That meant it was much more likely to get good tenants, as they were looking for well-run buildings with lower operating costs.