By taking a modern approach to insulation, residential building developers can maximise the usable area of their apartments, helping improve profit margins and return on investment.

The release of NCC 2019 introduced the Australian building industry to the concept of thermal bridging. This means bridging between building elements must now be accounted for when calculating the Total R-value of a built system to negate its impact on internal thermal comfort.

Thermal bridging is defined as a weakness (break) in the thermal envelope of your building. It is the path of conductivity between one side of the envelope and the other, where heat can travel or be lost through the building materials, like framing that forms part of your building envelope.

However, the impact of thermal bridging on internal comfort and energy efficiency can be negated by installing a continuous barrier of insulation that separates the bridging point from the internal lining of the building.

The Kooltherm range from Kingspan Insulation is an example of a more modern cost-benefit approach to continuous insulation as illustrated in a recent white paper commissioned by the company on a 23-storey apartment building.

This Class 3 apartment building featuring a concrete external wall construction was examined to quantify the potential space saving benefits that resulted from insulating with Kingspan’s high performance slimline Kooltherm K17 insulated plasterboard, in comparison with conventional steel stud and track wall systems using 90mm glass wool fibre batts. 

The study found that Kooltherm K17’s slimline design allowed for a reduction in wall thickness of 74mm, which meant there was more usable space without compromising the thermal performance, or the enjoyment of thermal comfort.

The external length of insulated wall across each floor plate was 62m. Based on a thickness difference of a 74mm wall, a 4.6m² floor footprint could be saved at each floor level, equating to 106m² across the 23 levels – equivalent to the size of two one-bedroom apartments.

Killian Smith, Kingspan Insulation’s technical services manager stated, ‘’As the release of the NCC 2019 Energy Efficiency Requirements continues to bring its challenges, at Kingspan we have created a compliant and slimmer insulation solution while still achieving the same level of thermal performance and comfort.’’

The rising real estate values place immense pressure on Australian developers and their design teams to maximise usable internal areas and boost returns on their investment. Every square metre of additional space created with the Kooltherm K17 system produces a net gain in value.