Geothermal Drilling at a Heritage Home in Kooyong, Melbourne

Project Overview:

GT Drilling executed a specialized drilling project for a heritage-listed residence in Kooyong, near the iconic tennis club in Melbourne. The initiative was led by Luxury Living Builders, with SóGeo serving as the heating and cooling installer for the upcoming ground-source system. GT Drilling’s tasks included drilling five boreholes to a depth of 120 meters, installing FRANK PE100 RC loops, and conducting thorough testing to ensure each probe’s readiness for future geothermal integration. Over two weeks, the team navigated heritage constraints, limited front-yard space, and layered geology, culminating in a discreet yet robust infrastructure for year-round comfort.

Goals & Scope:

The client’s primary objective was to lay the foundation for an efficient geo-exchange system—capable of providing geothermal heating and cooling—without compromising the property’s heritage status or local noise regulations. GT Drilling’s responsibilities covered drilling, loop installation, and borehole sealing, while SóGeo took charge of designing and eventually installing the interior components of the ground-source heat pump. By focusing on minimal exterior alterations and compliance with heritage standards, this approach preserves the home’s historic façade and ensures seamless integration with SóGeo’s planned HVAC setup.

Site Conditions & Drilling Methods:

The property’s heritage listing and minimal yard space demanded precise equipment logistics and careful scheduling. GT Drilling deployed the GT35 rig, leveraging its compact form and on-board mud pumps to handle varying strata. The initial 30–40 meters contained clay, giving way to basalt at depth. A mud drilling technique stabilized each borehole, ultimately reaching the required 120 meters. Once drilling concluded, the team inserted FRANK PE100 RC loops and grouted the boreholes from bottom to top to seal off any aquifers or fractures. This specialized grout further enhanced thermal conductivity, optimizing system efficiency for future geothermal operations.

Collaboration & Execution

Throughout the two-week schedule, GT Drilling worked closely with Luxury Living Builders to accommodate heritage requirements and maintain a tidy, low-impact worksite. Simultaneously, SóGeo provided input on loop design specifications, ensuring the probes aligned with the eventual heating and cooling framework they planned to install. Each loop underwent a comprehensive pressure test before final sign-off, guaranteeing reliable performance when SóGeo completes the interior mechanical systems.

Outcome & Significance:

With five 120-meter bores successfully installed and tested, this heritage home in Kooyong now has a discreet yet powerful geothermal infrastructure in place. By locating loops underground, the project preserves the property’s historic façade, avoiding any bulky external plant equipment. GT Drilling’s methodical drilling and mud-pumping approach, combined with SóGeo’s expertise in designing the future heat pump system, creates a foundation for modern, energy-efficient climate control. The collaboration underscores how heritage preservation, meticulous planning, and advanced geothermal techniques can coexist, delivering sustainable comfort in a manner respectful of Melbourne’s architectural heritage.