Around 80,000 buildings in Australia have fallen through the ‘green gap’ and are missing out on retrofit opportunities that would improve their energy productivity, resilience and sustainability.

While the bulk of the nation’s premium and A-Grade buildings have already been upgraded – and a massive 30 per cent of our CBD office space is now Green Star-rated – the lower end of the market has been slower on the sustainability journey.

The ‘mid-tier’ of B, C, and D-grade market continues to lag behind the leaders in terms of energy retrofits. A simple comparison is illustrative. While premium and A-grade buildings now average 4 star NABERS Energy ratings, the mid-tier market averages just 2.4 stars.

Our mid-tier buildings remain the lowest of the low hanging fruit. Our buildings present some of the cheapest and fastest opportunities to reduce our emissions, and we can do this with proven and readily-available technologies.

In 2015, the Australian Government Department of Industry Innovation and Science commissioned the GBCA to gain deeper insights into the mid-tier commercial office building sector, to identify key stakeholders, and to outline barriers and opportunities to drive change.

With the support of Sustainability Victoria, the City of Melbourne and EY, we hosted an industry think tank capturing the insights in a new report – Mid-tier commercial office buildings in Australia: A national pathway to improving energy productivity.

Of the 64 million square metres of commercial building stock around Australia, we estimate that just 12.7 million square metres is premium or A-Grade. The rest – around 52 million square metres – could be classified mid-tier.

Mid-tier office buildings are generally under 10,000 square metres, and tend to have a lower level of energy efficiency than premium or A-grade assets due to clunky HVAC systems, minimal controls and outdated lighting. It was also found that it was rare for these buildings to have an on-site dedicated team for facilities management.

The ownership profile of mid-tier office buildings is diverse. This makes communicating the business case for energy efficient upgrade a challenge, as the drivers for mid-tier building owners are as unique as they are.

Our think tank participants identified a range of actions and initiatives, all of which have been outlined in detail in our report. These include:

  1. Developing a robust and trusted evidence base
  2. Building a compelling and quantified business case for energy efficiency upgrades
  3. Creating a shift in awareness, knowledge and behaviour
  4. Developing and identifying tools to promote improved energy performance
  5. Establishing representative bodies and networks
  6. Promoting innovative financing mechanisms.

We already know how to take these buildings from carbon-hungry dinosaurs to exemplars of energy efficiency.

Wollongong City Council achieved Australia’s first 5 Star Green Star – Performance rating for its Administration building in 2015. First occupied in 1987, the 13-storey building is a great example of how older assets can be retrofitted, modified and tweaked to gain long term sustainability.

Over the past decade, council’s environmental sustainability officer Dr Carl Hopley and building manager David Peterson implemented a range of energy upgrades, including a new heating, ventilation and air-conditioning system, heat reflective blinds and lighting upgrades. These interventions halved energy consumption.

But wanting to benchmark their building’s performance against best practice, Hopley and Peterson turned to the Green Star – Performance rating tool for existing buildings. The process enabled the building management team to identify additional energy efficiency opportunities, from HVAC maintenance to adjustments to lighting.

In the last 12 months, council has “trimmed a bit more energy consumption off the building through ongoing commissioning and fine tuning,” Hopley explained.

“We simply looked for opportunities to improve the building’s performance. The result demonstrates how regular building tuning can deliver improvements in sustainable performance.”

There are old buildings all over Australia that can become exemplars of energy efficiency. It’s time to work together to help them get there.

Download the Mid-tier commercial office buildings in Australia: A national pathway to improving energy productivity.