Proposed Residence @ Legana, TAS – VURB Performance Solution

NCC energy efficiency requirement energy compliance performance solution BCA VURB


Verification Using a Reference Building (VURB)

Our added value

We were engaged to undertake a VURB Performance Solution to reduce the overall glazing cost of the project by avoiding thermally broken aluminium windows. Since the building was located in climate zone 7, only a reduction in the heating demand of the building more than that of the reference building could build our case against the energy efficiency requirements of the NCC. The window thermal performance outcome from the ABCB Glazing calculator for the first floor was relatively high and the complying performance requirement was as low as U1.1 thus, the DTS pathway was not an option at all. Averaging out the ground floor and second floor, using NatHERS, the average complying U-value of the windows was U2.6.

Heat loss due to the large perimeter of the building was high and we proposed a 50mm XPS slab edge insulation as a treatment. For 140mm external walls, we allowed 90 mm+50mm 32 kg/m3 sound insulation (total R4.2), a roof blanket with reflective vapour permeable foil facing and R6.0 ceiling insulation.
Having these changes implemented, we managed to increase the overall U-values from U2.6 to U3.4 (more than a 30% increase). Several other measures to further reduce the construction cost was also proposed in our summary report, but the client was happy with our solution and the energy report was finalized with no further changes.

NCC VURB Performance solution Energy efficiency thermal modelling
NCC BCA energy efficiency thermal modelling assessment VURB energy performance solution