Investa – Lifting a Premium Asset from 5.0 to 5.5 Stars with Strategic Optimisation
Investa is one of Australia’s leading commercial property groups, known for its focus on sustainability, data-driven operations, and portfolio-wide performance. At 259 Queen Street in Brisbane—a premium commercial asset with a strong NABERS track record—Investa partnered with Bueno to take an already 5.0-star NABERS Energy rating even higher.
The goal was to push the building’s performance to 5.5 stars, enhancing its market appeal, reducing operating costs, and strengthening its value as a government-leasable asset. Through advanced analytics and targeted optimisation, Investa aimed to demonstrate that even high-performing buildings can go further—with measurable benefits for owners, tenants, and sustainability outcomes.
The Challenge – Outperforming during extreme cooling demand
In 2024, Queensland experienced a 30% increase in Cooling Degree Days (CDD) compared to the previous year, placing additional stress on HVAC systems across many buildings. While most assets in the region saw a spike in energy consumption over summer, Investa and Bueno worked to reverse the trend at 259 Queen Street—balancing emissions reduction with high tenant comfort expectations.
The Journey Begins – Targeted fault insights and collaborative optimisation
Bueno’s Performance Services team worked closely with site staff to identify and resolve inefficiencies using high-integrity fault detection and analytics. The focus was on isolating mechanical system drift, correcting sensor/control logic issues, and optimising setpoints and runtimes across critical systems:
Chilled Water System
Overshooting issues from Chiller 1 were resolved by replacing faulty sensors and adjusting control logic.
Savings: 11,500 kWh / ~$2,300 annuallyTenant Condenser Water System
Installation of VSDs and pressure control logic upgrades.
Savings: 70,000 kWh / ~$11,000 annually
NABERS impact: +0.04 starsCooling Tower Systems
Fan logic and temperature resets improved performance outside operating hours.
Savings: 96,000 kWh / ~$16,500 annuallyZone Temperature Control
Lockouts applied to heating coils, tenant AC setpoints adjusted.
Savings: 17,500 kWh / ~$3,500 annually
The Results – Lifting performance while reducing summer load
Even in one of Queensland’s hottest recorded summers, 259 Queen Street recorded a 4.5% energy reduction, outperforming market norms. The combination of strategic fault detection, targeted system improvements, and close site engagement delivered:
Total electricity reduction (summer): 187,000 kWh
Annualised site action savings: 195,000 kWh / ~$33,300
NABERS uplift: Now tracking at 5.57 Stars
Thermal comfort: Maintained at 93%
These results highlight the ability to lift performance in high-grade buildings through detailed optimisation, even under seasonal pressure.
Next Steps – From high performance to sustained leadership
Investa’s success at 259 Queen Street shows what’s possible when building analytics and operational expertise align behind a common goal. Moving from 5.0 to 5.5 stars not only improves environmental outcomes—it adds leasing flexibility, cost savings, and asset value.
With Bueno continuing to support optimisation efforts across its broader portfolio, Investa remains well positioned to meet evolving standards, sustainability targets, and tenant expectations in a competitive commercial market.
