Electrifying an existing commercial building is rarely a straight equipment swap.
A groundbreaking project in Australia’s commercial sector, the refurbishment of 11 Mounts Bay Road in Perth will transform the heating system of the existing office tower from gas-fired boilers to electric heat pumps.
Although the 5-storey building presents certain challenges, the team is committed to meeting global climate goals, aiming to phase out gas use and achieve net zero emissions.
Here are the standout challenges and opportunities from the project.
Challenges
Physical space constraints
The existing boiler footprint was far smaller than the space needed for most heat pump configurations, especially high-temperature and water-sourced systems.
Balancing heating and cooling
In several configurations, new electrified plant would have compromised cooling capacity or forced major electrical upgrades which added both cost and operational risk.
Embodied carbon and demolition load
Some electrification paths required full removal of relatively young chillers (~5 years old), creating unnecessary embodied carbon waste. The mechanical solution had to avoid discarding functional plant while still supporting electrification goals.
Efficiency penalties
High-temperature heat pumps (to mimic boiler operation) resulted in poor energy efficiency and performance, making them unattractive from both operational and sustainability perspectives. Mechanical engineers had to rethink the water temperature strategy instead of chasing like-for-like output.
Power supply uncertainty
A major site power upgrade looked to be necessary, particularly where heating and cooling loads might stack. Mechanical and electrical teams had to model load profiles carefully to confirm that peak electrical demand actually occurs during cooling, not heating. This avoided an unnecessary electrical infrastructure upgrade.
Unknown performance of existing equipment
Because heat pumps generally supply lower flow temperatures than gas boilers, we weren’t sure whether existing heating coils could still deliver sufficient output at 55°C. Mechanical teams validated this by temporarily reducing boiler temperatures and monitoring BMS performance during winter, an essential real-world test.
Opportunities
Right-sizing plant
Although the installed boilers totalled 800 kW, site feedback revealed only one boiler operated at a time and heating demand rarely exceeded ~400 kW. This unlocked major opportunities: smaller modular heat pumps, reduced capital cost and easier integration into the plantroom.
Modular heat pumps simplify installation and access
Smaller units could pass through the existing access hatch, avoiding crane lifts and reducing disruption, cost and safety risks. Mechanical design becomes more flexible with modular, scalable equipment.
Confidence in lower-temperature heating
The winter building management system (BMS) trial validated that the building could maintain comfort at reduced water temperatures. This finding dramatically widened the range of viable heat pump options and improved system efficiency. It also removed the need to replace heating coils, saving capital and reducing waste.
Buffer tanks add resilience and efficiency
Thermal storage allows heat pumps to charge overnight at milder ambient temperatures, improving energy performance and offsetting performance drop-off during cold periods. This enables smaller plant and smoother system operation.
Electrification delivers clearer long-term benefits
Heat pumps with a coefficient of performance (COP) of ~3 are close to parity with gas. As the Perth grid becomes cleaner, emissions reduction will accelerate.
A whole-of-building optimisation rather than like-for-like swap
The project highlights that electrification is not a mechanical equipment replacement exercise, it’s an opportunity to reassess load profiles, rethink system temperature strategies, integrate heating and cooling more intelligently, reduce embodied carbon and improve resilience.
