The Australian Building Codes Board is seeking to mitigate the impact of the Australian construction industry on the environment by increasing the energy efficiency of buildings by up to 40% by 2030.
In May 2019, the National Construction Code (NCC) was updated with new requirements for the energy efficiency of buildings (Section J, Volume 1). These requirements specifically referenced a New Zealand Standard in NZS4214:2006 as the method to determine the total thermal resistance of parts of the building. The introduction of this method meant thermal bridging between building elements must be accounted for in thermal calculations, directly impacting the Total R-Value of the building elements.
Thermal bridging is defined as a weakness (break) in the thermal envelope of a building. It is the path of conductivity between one side of the building envelope to the other, where heat can travel or be lost through building materials.
The impact of thermal bridging on internal comfort and energy efficiency is negated through the installation of a continuous barrier of insulation. This combats the effects of thermal bridging, limiting the amount of heat escaping or entering the building envelope via thermal bridges, along with achieving a higher energy efficiency rating.
To demonstrate how the total thermal resistance of parts of the building impacts different types of insulation materials, Kingspan Insulation enlisted Norman Disney & Young to conduct a thermal performance comparison assessment. The assessment compared the performance of a traditional wall lining system with bulk insulation against Kingspan Kooltherm K17 insulated plasterboard wall lining system.
The total system R-Value within a wall construction can be impacted quite significantly when thermal bridging is factored into the calculation. From their assessment, Norman Disney & Young were able to calculate the required thickness of insulation and total wall thickness necessary to achieve the required R-Value targets according to NCC 2016. To do this, R-Values total targets of 2.8 and 3.3m²K/W must be attained.
The key benefits
Kingspan Kooltherm K17 represents a new approach to wall insulation, achieving these targets with up to 60% thinner walls (complete wall thickness) in comparison to the traditional wall lining system. This means when thermal bridging effects are calculated and offset, walls lined with Kingspan Kooltherm K17 insulated plasterboard can be 170mm – 310mm thinner than walls lined with a traditional wall lining system (with bulk insulation).
The study looked at a floor plan with 6 apartments (ranging between a 44m² studio, 50m² one bed and a 75m² two bed apartment) in a Class 3 apartment building project, comparing a traditional wall lining system against a wall system lined with Kingspan Kooltherm K17. Across each floor plate the external length of insulated wall was 41m. Based on a thickness difference of a 170mm wall, a 6.5m² floor footprint could be saved at each floor level, equating to 98m² across the 15 levels – the size of two additional studio apartments.
Keith Anderson, Kingspan Insulation technical R&D manager states, “The key feature that differentiates Kingspan Kooltherm K17 insulated plasterboard wall lining system from a traditional wall lining system is that the insulation layer in the former is not bridged by a higher thermal conductive material (e.g. steel studs).’’
Overall, Kingspan Kooltherm K17 insulated plasterboard delivers a high thermal performance solution, with a more efficient use of space while reducing your energy costs. Using Kingspan Kooltherm K17 insulated plasterboard as a continuous layer of insulation helps manage the effects of thermal bridging and reduces wall thickness.
While real estate values continue to be at a premium, Australian developers and their design teams will continue to be under increasing pressure to maximise usable internal areas to boost returns on their investment. Every square metre of additional space created with the Kooltherm K17 system produces a net gain in value.
Read the white paper created by Norman Disney & Young.