This year on The Block, you get a chance to see how to build an energy-efficient 7-Star rated home

With rising energy costs and people becoming more concerned about a sustainable future, 7-Star construction offers a significant improvement in energy efficiency. This improvement is also reflected in the new National Construction Code (NCC2022), which mandates a minimum 7-Star rating for all new homes after 1st October 2023.

The Block shows that this level of performance is achievable and doesn’t have to add a lot of complexity or cost to a new build. A thoughtful approach to a house’s design and the choice of materials can make a big difference to achieving this new target and improving energy efficiency.

This is where CSR can help.

Insulation & Wall Wrap

All homes targeting 7 Star performance can benefit from increased levels of insulation in the ceiling, wall and floor. Additionally, the use of roof insulation can help improve acoustic performance of your home. All the homes on The Block installed premium insulation from Bradford Insulation – Bradford’s Gold Wall Insulation Batts.

Insulation helps to improve the building’s ability to reduce temperature fluctuation by slowing down external summer heat transfer and internal winter heat transfer. The greater the R Value, the greater the resistance to heat transfer, and the greater the insulating effect and subsequent energy savings.

It is also important to look at moisture control in new builds, which can include the installation of a vapour permeable Enviroseal RW Plus Wall Wrap (included on every house on The Block in 2023). Enviroseal™ Wall Wraps are additional layers of protection that shield your home from external water-related weather damage and accumulation of internal condensation which can result in mould or rot. Wall wrap can also assist in minimising draughts which can reduce the effectiveness of insulation


Ventilation is key to  managing the risk of moisture accumulating in the building structure and reducing temperature buildup. Excess moisture in the roof space can contribute to condensation formation which can result in mould, water staining and long-term structural damage if left unattended. The NCC now requires mandatory ventilation of the roof space in cold climates to manage this risk.

About Bradford Gold and Gold High Performance Batts

Bradford Gold™ insulation for walls is specifically designed to deliver optimal performance in exterior cavity walls. Bradford Gold wall batts are available in R-Values up to R2.7. Manufactured from Glasswool with a recycled glass content up to 80%, the batts are one of the most environmentally friendly insulation options available.


  • 7 Star Rated
  • Bradford
  • Bradford Insulation
  • Bradford Ventilation
  • Energy Efficient
  • The Block 2023