On a journey to build their dream house, husband and wife DIY duo, Alexander Roberts and Imogen Gilchrist, better known as Al and Imo, were looking to design a 7.5-star energy efficient house in Torquay, Victoria.

The project came at a crucial time as Victoria has taken a significant step towards a greener future by raising the minimum energy efficiency standards for new homes from 6 to 7 stars, aligning with the National Construction Code of Australia 2022. Energy efficient homes are more comfortable to live in, cost less to heat and cool, and help reduce greenhouse gas emissions. That’s why Al and Imo decided to go beyond the new minimum required 7-star energy efficiency standard and build to a higher star rating. They dubbed their home ‘The Good Day House’.

What was the challenge?

As part of the home’s modern design, large windows featured prominently. While this was designed to maximise natural light, it would also make the interior more susceptible to the change in seasonal temperatures. Given the diverse climate in Victoria, characterised by cold winters and hot summers, high performing insulation is a crucial component for an energy-efficient home. The couple was, therefore, eager to ensure the house had an excellent thermal performance while being as sustainable and energy efficient as possible. Another significant requirement for the family of four was to ensure good acoustics in their spacious house. The DIY enthusiasts, Al and Imo, were in search of a durable, sustainable high-performance solution that was easy to install.

What was the solution?

Building energy efficiency into the home’s foundations, Al and Imo selected Knauf Insulation’s Earthwool® product range for the entire home.

High Density R2.5 Earthwool SoundShield batts were installed in the interior walls to enhance the acoustic performance in the house, stop the spread of noise between rooms, and create a more peaceful indoor environment.

The extremely high thermal performing Earthwool R6.0 Ceiling batts were placed in the ceiling cavity. This solution offers superior energy-saving properties and acts as an effective barrier against extreme temperatures.

Earthwool is made using up to 80 per cent recycled glass and with ECOSE Technology, a sustainable, bio-based binder that contains no added formaldehyde or other harmful chemicals. Moreover, Earthwool represents no known threat to the environment – it comes with ‘Red List Free’ DECLARE Label and GreenTag Level A certification. These certifications aim to provide transparency around sustainability and health and safety.

Prior to ordering their insulation, Al and Imo researched the market’s leading products and found that Knauf Insulation ranked best for sustainability and performance, commenting, “We knew that investing in a quality product meant that, long term, we’d save money and energy, whilst living in harmony with our values. For maximum efficiency, it’s important to order batts to the correct width of the studs and cut them to size so they fit nice and snugly.”

By selecting the Earthwool product range, the DIY enthusiasts were able to install most of the insulation in a single day. “We wore long sleeves, long pants, gloves and safety glasses expecting it to be really itchy and tough to work with; however, we found that the insulation was really soft and wasn’t as itchy as we expected.”

What was the result?

Following completion, The Good Day House achieved a rating of 7.5 stars (74.8 MJ/m^2), exceeding the new minimum NCC standards. It stands as a testament to what can be achieved in sustainable home construction, setting a new standard for energy-efficient homes in Australia. The home's design reflects sustainability and future living, with an orientation around a courtyard and an open-plan, light-filled, and well-ventilated layout. The strategic use of Knauf Insulation products gives Al and Imo peace of mind that their home has been constructed with sustainability and energy efficiency in mind from beginning to end.

“Living in our 7.5-star energy-efficient home feels amazing," Al and Imo expressed. "We have put so much thought and effort into creating a space that reflects our passion for good design and aligns with our commitment to sustainability."

“Installing quality insulation into The Good Day House ensures that all the sustainable features that we’ve incorporated into the build are working to their full potential, meaning that, long-term, we get more bang for our buck. Additionally, the acoustic insulation batts, which are denser than thermal insulation batts, mean they are really effective at reducing sound travel between spaces.”

Al and Imo expect to save hundreds of dollars a year on their energy bills, thanks to the benefits of the Knauf Insulation products, which have been an integral element in delivering the energy efficiency outcomes of The Good Day House. The project serves as a living example of future Australian architecture and sets a precedent for energy-efficient homes.

Project details

Project: The Good Day House

Location: Torquay, Victoria

Application: Ceiling and Walls

Construction type: Residential — House

Products Used:

• Earthwool SoundShield R2.5HD
• Earthwool R6.0 Ceiling Batts

Supplier: Pricewise Insulation