Most commercial sites can cut whole building energy use by 15 to 30 percent within 12 months. I have watched it happen again and again when teams follow a clear sequence: audit first, tune controls and lighting, tighten the envelope, then tackle plant and onsite generation. You will track progress with simple metrics like electricity per square metre and peak demand.
You will focus on low risk actions before larger capital investments. Once data proves the returns, you can step up with confidence. The result is lower bills, better compliance, and occupants who stay comfortable all year.
Define Success and the Metrics That Matter
Clear targets turn vague ambitions into measurable results.
Link your goals to NABERS, the National Australian Built Environment Rating System. It scores buildings from zero to six stars, and each rating lasts 12 months. A six star building produces roughly half the greenhouse emissions of a five star performer.
Understand the Commercial Building Disclosure program as well. Office spaces of 1,000 square metres or more usually need a Building Energy Efficiency Certificate before sale, lease or sublease. Track base building and whole building energy separately so tenant plug loads do not inflate your base building performance.
Recommended Metric Targets
Benchmark whole building electricity quarterly against a rolling 12 month baseline.
Aim for fittings at 100 to 120 lumens per watt.
Target 10 to 20 percent peak shaving through controls and staged equipment starts.
Maintain comfortable temperature and glare control so tenants stay satisfied.
Regulations You Must Align To
Compliance alignment prevents costly redesigns later.
From October 2023, Section J of NCC 2022, the National Construction Code, applies nationally. Always confirm local adoption notes with your certifier before procurement begins.
Focus retrofit work on J4 building fabric, J6 HVAC (heating, ventilation and air conditioning) systems, J7 lighting and power, and J9 energy monitoring. Part J9 requires time of use meters for buildings over 500 square metres, and sub metering of major services over 2,500 square metres. You must also reserve at least 20 percent of roof area for future solar.
Start With Data: Metering, Baselines, and Audits
Good data builds a defensible business case.
Gather at least 12 months of interval electricity data and all energy tariffs to capture seasonal patterns.
Follow AS/NZS 3598.1, the commercial energy audit standard, for commercial buildings. Type 1 gives you a high level scan. Type 2 adds robust financial evaluation.
Type 3 supports investment grade design and measurement plans. Prioritise sub metering of HVAC, lighting, plug loads, lifts and hot water so you can separate base building from tenant use.
Facade and Glazing: Cut Solar Heat First
Addressing the envelope reduces cooling loads before you touch the HVAC.
In Australia, HVAC can account for up to 50 percent of a commercial building's energy use. Tackling solar gain at the facade reduces plant runtime and capacity needs significantly.
Government guidance notes that some window films can halve the solar heat gain coefficient of existing glazing. External shading can block up to 90 percent of incoming solar heat. Target a lower solar heat gain coefficient (SHGC) on west and north exposures in hot and mixed climates.
On many sites, facilities teams first map where summer heat loads and glare are worst, walking the facade with thermal images and tenant feedback. This helps you prioritise panes and orientations before you invest in films or external shading. If west facing glass is driving afternoon heat spikes, consider Sunguard Australia for commercial window tinting to cut solar heat gain and glare while preserving daylight and occupant comfort. Test a small area first and check glare levels before a full rollout.
Lighting Upgrades That Pay Off Quickly
LED retrofits deliver fast, visible savings while improving light quality.
Lighting can use up to 40 percent of energy in commercial premises. LEDs use up to 75 percent less energy than halogens and can last 25 times longer.
Set clear specification targets. Aim for fittings at 100 to 120 lumens per watt with a colour rendering index of at least 80.
Install occupancy sensors in intermittently used spaces and daylight harvesting near windows. Engage tenants early to agree on after hours policies. Label circuits and sensor zones clearly so maintenance teams can troubleshoot without disabling controls.
BMS Tuning and Low-Cost HVAC Optimisation
Tuning existing systems can unlock double digit savings before you spend on major plant.
Studies on hundreds of buildings show commissioning can cut whole building energy use by around 16 percent, with one to four year paybacks.
Focus your building management system (BMS) tuning on chilled and hot water reset, supply air temperature reset, outdoor air economiser operation, static pressure trim and variable speed drives. Define expected outcomes, such as fewer hours with simultaneous heating and cooling, lower peak fan power from pressure resets and shorter after hours runtime through tighter overrides.
On-Site Renewables and Storage
Your roof can cut daytime grid draw and carbon emissions in a visible way.
For small commercial rooftop PV (solar photovoltaic) systems between 15 and 100 kW, typical payback runs about two to five years with current incentives. Design to NCC J9 solar readiness by reserving at least 20 percent of roof area.
Size arrays to building daytime load first, then assess batteries for tariff shifting and resilience. Follow grid connection steps early, including preliminary approval from your distribution network service provider (DNSP) and voltage rise studies, to avoid delays. For sites ready to electrify and cut daytime grid draw, Expert Electrical TAS can solar power commercial installations sized to your roof area and load profile, while streamlining grid approvals and paperwork.
A 12-Month Sequencing Roadmap
A phased approach lets you move fast without losing control.
Quarter one: complete the audit, implement metering, fix schedules and capture no cost control wins. Quarter two: deliver lighting upgrades and facade measures with mock ups that prove comfort gains.
Quarter three: commission and tune HVAC, replace end of life equipment with variable speed alternatives and finalise hot water electrification designs. Quarter four: install PV, consider batteries if tariffs justify them, and close out measurement and verification so you are ready for your next NABERS rating.
Conclusion
Start with an audit and data, prioritise controls and lighting, address the facade where it hurts most, then step into plant and rooftop generation when the numbers add up.
Track what matters, align with Australian codes and rating schemes, and build repeatable practices so improvements stick.
With a sequenced approach, you can reduce costs, improve comfort and show measurable progress within a year without unnecessary risk. The path forward is clear. Take the first step this quarter.
FAQs
These short answers cover the questions that building teams keep coming back to.
How quickly can a typical site see noticeable reductions in electricity bills?
Zero and low cost actions like correcting time schedules and enabling economic cycles can show impacts within one or two billing cycles. Commissioning studies indicate median savings near 16 percent in existing buildings when tuning is done well.
What should I fix first if I only have a small budget this quarter?
Start with data and controls, and confirm schedules, trims, and sensor accuracy. Then move to targeted lighting and simple facade measures that address glare and hot spots. Document each change and monitor results weekly to build your case for the next investment round.
How do I ensure upgrades help my disclosure obligations and ratings?
Coordinate scope with Section J triggers and confirm requirements with your building certifier early. Plan the timing so upgrades align with NABERS re-rating windows, and verified savings count toward the next certificate period.
When does storage make sense alongside rooftop solar?
Consider batteries after you size solar to daytime loads. Evaluate tariffs, demand charges, and resilience needs to justify capacity. Pilot with a modest system and expand only if measured savings meet targets.
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