Energy efficiency assessment reveals building's star quality

An independent assessment has awarded Environment Canterbury’s Tuam Street offices with a 4.5 star energy efficiency rating for its energy consumption for a 12-month period through to October 2018, which equates to “excellent performance” on the NABERSNZ scale.

National Australian Built Environment Rating System New Zealand (NABERSNZ) is an office energy performance benchmark licensed by Energy Efficiency and Conservation Authority (EECA) and administered by the New Zealand Green Building Council. It is used by all New Zealand’s publicly listed commercial property firms to help them improve energy use and reduce carbon emissions.

Factors considered

The NABERSNZ assessment of the office carried out by Global Action Plan Oceania, involved: 

  • conducting a computer count to indicate building occupancy;
  • surveying staff for an indication of hours of use;
  • gauging meeting room use;
  • measuring generator consumption; and
  • measuring power consumption.

The culmination and analysis of this data allowed the building to become NABERSNZ Energy certified with a 4.5 star performance rating. The NABERSNZ scale is from 0 to 6 and shows energy performance compared to other buildings.

Interestingly, there has only been one other ‘whole building’ rating in Christchurch, the IAG Building, which received 5.5 stars.

Aim high

Bronwyn Simmonds, Asset Services Manager at Environment Canterbury, said: “As a signatory to the Local Government Leaders’ Climate Change Declaration, formally benchmarking the performance of our building is a great way to demonstrate the actions that we are taking internally to mitigate climate change and reduce running costs.

″Our excellent energy efficiency is due to a number of factors, including our quality new building, constant commissioning of our plant and time settings, and positive changes in staff behaviour.″

She continued: “Our rating was right on the cusp of a five star, so given that solar panels have been installed since this rating and we have made further positive changes to our settings, I would expect to be reporting an ever better rating later this year.”

Rating scale

For reference, the NABERSNZ rating system is as follows:

  • 0 stars = very poor performance
  • 1 star = poor performance
  • 2 stars = below average performance
  • 3 stars = good performance
  • 4 stars = excellent performance (NB ECan’s current level)
  • 5 stars = market-leading performance
  • 6 stars = aspirational performance