14.02.2018 : Alan Barbour

Energy efficiency – what next for commercial buildings?

33 Customhouse Quay in Wellington has been accredited by the New Zealand Green Building Council (NZGBC) with a 6 star NABERSNZ rating for energy performance – the first New Zealand building to achieve the top 6 star rating. We caught up with Alan Barbour, who was responsible for the environmental design of the project, to talk about this benchmark for commercial energy efficiency.

33 Customhouse Quay has been awarded a 6 star NABERSNZ rating – why is this significant?

While a few buildings have previously achieved 5.5 star ratings (including Beca’s refurbishment of Aorangi House, our Wellington office), 33 Customhouse Quay is the first building in New Zealand to be awarded the maximum 6 star NABERSNZ rating for measured energy use.

The building was designed and constructed to be a leading edge building, and to set new benchmarks for sustainability and efficiency. The 6 star NABERSNZ rating confirms the value added by the combination of low energy design and the ongoing commitment of the landlord and tenant.

What impact will the rating have on the wider commercial property market?

33 Customhouse Quay was designed to set new benchmarks for energy and environmental performance, to encourage the commercial property market to improve performance. Now that a 6 star rating has been shown to be achievable, we expect that some clients and tenants will choose to target a 6 Star rating as an aspirational goal for their buildings.

What changes are we likely to see in terms of improving the energy efficiency of commercial buildings over the next few years?

We now have much better operational data from New Zealand buildings to feed back into continual design improvements. Designs are regularly targeting improved performance outcomes, so we expect the main change will be an increase in energy performance agreements and more focus on high return specialist services. Building tuning, for example, utilises dashboards and new diagnosis software tools such as ‘B-Tune’ to offer significant savings and short payback periods.

What’s stopping us from bringing all commercial buildings up to this standard?

The value equation must work for the building owners and for the tenants and this needs to be assessed on a case by case basis. For some projects, a lower standard of efficiency is the right outcome to ensure that the design and operational needs of the project align with its financial models.

On the other hand, there is still a perception that significant capital must be invested in order to achieve high levels of energy performance. A focus on whole of life costs, as opposed to initial capital costs, can overcome this barrier, as can having a wellbeing focus that considers the improved health, comfort, and productivity benefits of an energy efficient building.

For existing buildings, we encourage our clients to make the best use of what they already have, as opposed to seeking major refurbishments. By monitoring, understanding energy consumption, and tuning the building services so they operate as effectively as possible, we can make significant energy savings in a cost effective way. With technological advances, we can analyse masses of system performance data to automatically detect inefficient operation. Shaan Cory leads B-Tune, Beca’s building tuning service. B-Tune uses an advanced technology platform to support our building scientists to consistently find annual energy savings of 10-30% with little capital expenditure on the building systems.  

How can we overcome the challenges to making all commercial buildings energy efficient?

Energy Efficiency and Conservation Authority (EECA) funding helps and Beca is a programme partner of the EECA. The key is to align the design and construction and operation phases, to set ambitious targets and to keep these targets in mind throughout the process to reach a successful outcome.

Ultimately in NZ this is likely to be market driven, unless the NZ government introduces mandatory disclosure, which has been a major driver for energy performance in Australia. There also needs to be more demand from tenants for low energy buildings.

How do the Australian and New Zealand markets compare in terms of building energy efficiency?

In terms of energy efficiency, the Australian building code is more mature than New Zealand, and requires the whole building to be assessed, including all building services, to meet a minimum level of energy efficiency. This means that the bare minimum level of performance is higher than in New Zealand.

However, the carbon intensity of the Australian electricity grid is vastly higher than in New Zealand, meaning that this can, in some cases, encourage the use of gas as opposed to electric heating while delivering lower carbon emissions overall. New Zealand clients don’t have the opportunity to purchase Certified Green Power to improve the carbon intensity of a building rating as the renewables component in the NZ grid is low carbon already.

Beca is consistently sharing learnings across our hubs, seeking to use the best practice examples from each region to improve performance and value outcomes for all our building designs.


Find out more about B-Tune.


Client: Stride Property Ltd

Architect: Studio Pacific Architecture in association with Peddle Thorp

Tenant: Meridian Energy Ltd


NABERSNZ is a system for rating the energy efficiency of office buildings. It’s an independent tool, backed by the New Zealand government. In addition to the cost savings and environmental benefits of reducing energy use, benchmarking the energy performance of efficient buildings can also increase property value. Ben Masters leads Beca’s NABERSNZ and Green Star Performance assessments.

Image courtesty of Simon Devitt Photographer.

About the Author

Alan Barbour

Technical Director - Building Services

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