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Case study: Energy efficiency tips from the experts

Case Study | 15 Jul 2021

A powerhouse of professionals, known as NABERS Accredited Assessors, have worked tirelessly over the last two decades to help measure and manage the performance of buildings. We checked in with three of them to find out their top tips for energy efficient offices.

NABERS by the numbers

  • More than $1 billion in energy costs have been cut from bottom lines since NABERS started assessing building energy efficiency in 1999
  • A massive 78% of Australia’s office space is now rated with NABERS
  • More than 7 million tonnes of carbon emissions have been saved – enough to power 93,430 homes for a year.

Energy efficiency in seven steps

While Australia has made great strides toward energy efficiency over the last two decades, commercial buildings are still responsible for around 10% of our greenhouse gas emissions.

But there are several quick wins for any building owner looking to up the energy efficiency of their asset – and few people are better placed to understand than those on the ground assessing energy performance.

NABERS relies on an army of independent assessors – each skilled in the management and operations of buildings, and with expertise in energy and water efficiency, waste management or indoor environment quality.

We asked three experts – NettZero’s Michelle Tommosgård, Grosvenor Engineering’s Jake Xerri and DeltaQ’s Grace Foo – for the low-hanging opportunities hidden in plain sight. Here’s what they said…

1. Measure first for better management

“We cannot manage what we don’t measure,” says Michelle, Senior Sustainability Engineer and National Technical Manager with NettZero. Michelle and her team at NettZero have undertaken more than 1,800 NABERS ratings over the past 12 years, so she speaks from hard-won experience.

“Any building management team looking to achieve better energy efficiency should always start with the basics,” Michelle explains. The quickest wins are usually found after determining the areas that consume the most energy. This may be mechanical or electrical, it could be your common areas or may be an energy-hungry tenant. “My message is: measurement, measurement, measurement,” Michelle says.

2. Deep dive into the data

Grosvenor’s Sustainability Engineer Jake Xerri is part of a network of engineers working more than 19,000 properties around Australia. Jake is inspired to help his clients save money and reduce their environmental impact simultaneously – and that starts by getting his hands on historical electrical meter data. “This is an effective and relatively inexpensive way to see how your building is performing,” Jake says. As you dive into the electrical consumption data, expect to spot trends, see long-term patterns and find sources of energy waste. “You’ll quickly notice if there is unusually high electricity usage, like a pump left running, during after-hours periods and then you can take steps to rectify it.”

Committing to a NABERS rating sends a fundamental message to your tenants that your team is paying attention to building performance and wants to improve it over time. That’s a powerful message that is likely to make tenants want to stay or draw in new tenants. - Jake Xerri, Sustainability Engineer, Grosvenor Engineering Group

3. Take the time to tune in

Building tuning remains the “low-hanging fruit” of energy efficiency, says Grace Foo, Principal Consultant with DeltaQ. Grace has managed and delivered energy-efficiency projects for more than a decade and is a key contributor to government policy work, including revisions to energy efficiency provisions in the National Construction Code.

Grace says building tuning remains a “largely untapped opportunity” because it has “low marketing currency”. New solar panels on the roof are “very visible”, but building tuning is hidden from tenants. “But it’s not surprising to get a 15% to 30% reduction in energy consumption just by ensuring control set points are reset, based on demand, to maximise equipment performance.”

Grace recently analysed energy reduction, skilled job creation and emissions abatement potential of investments in solar, lighting or building tuning. The results? “We found building tuning created the most value,” Grace says.

4. Organise your admin

One of the easiest ways to improve a building’s energy efficiency is found in sorting out simple back-end systems, advises Jake. Organising paperwork, creating easy-to-use templates and ensuring diagrams and building schematics are up-to-date may seem mundane. “But it is astonishing how much time is lost trying to find missing documents and collect data that has been scattered about,” Jake observes.

“I’ve seen multiple occasions where sub-meters within a building could not be located because schematics were incorrect. Rectifying these discrepancies can help clear up knowledge gaps, and in some cases realise significant savings. Once you get your systems in order, you’ll free up time to start looking into the parts of your building that could use improvement.”

NABERS communicates complex and technical measures in a simple message of 6 stars – and this has been an incredibly powerful tool to make the invisible efforts in the plant room visible. For building owners, this means greater ability to access finance, the ability to track and report on progress with ESG obligations to stakeholders and to differentiate your portfolio's standing from your peers. - Grace Foo, Principal Consultant, DeltaQ

5. Let there be light

Heating ventilation and cooling chews up around 39% of a typical office building’s energy budget, so it’s easy to see why building owners and managers focus on HVAC. But lighting is responsible for a quarter of energy consumption.

“I’m always surprised to see how many buildings still use T8 fluorescent and halogen downlights,” Jake says. LEDs use about 75% less energy than halogen light bulbs and last up to 10 times longer, reducing replacement costs and the number of light bulbs that find their way to landfill. And with a payback period of less than one year, it’s easy to see why lighting upgrades are a quick win.

6. Upskill for uplift

Buildings may be bricks and mortar, but they are entirely dependent on people to ensure they perform at their peak. NettZero’s Michelle says energy efficiency training is an essential element in good management. “People operate buildings. When they are well trained and supported by good measurement reporting, they better decisions.”

NABERS is an excellent platform to benchmark building energy usage. Over time, I think NABERS Indoor Environment ratings will have a big impact too. Tenants may sign their lease based on a building’s indoor environment quality. When this is the case, a NABERS rating will be a deciding factor. - Michelle Tommosgård, National Technical Manager and Sustainability Engineer, NettZero

6. Rethink and rest

Buildings are evolving, living organisms that, with help, can continually adapt to their conditions. All three Assessors agree that Covid-19 has presented unparalleled learning opportunities for building owners and managers.

Most buildings increased their energy and water performance during the Covid-19 period, and “some stood out for their impressive responses to changed conditions,” Jake says.

“NABERS data has shown us the extent to which building owners have been unable to turn down services due to leasing arrangements and failures in design,” Grace adds. She points to one building she worked with that was “physically unable” shut off services to 80% of its area. “The building had to run at 100% to service the 20% of area which was still occupied.”

“NABERS gave us a standardised measurement system that made it obvious which buildings were performing well during lockdowns and lower occupancy and which ones could use more attention,” Michelle adds.

Armed with that knowledge, our army of NABERS Accredited Assessors can make Australia’s commercial offices even more efficient.