Lauren and Scott, the homeowner’s, alongside Sally from Sash Architecture, engaged us after developing their home’s conceptual design, to investigate and understand their home’s energy efficiency performance.

This home is Lauren and Scott’s forever home, and with 2 children, wanted to make sure their home was going to be healthy and comfortable today, and well into the future.

By moving through Step 1, we were able to showcase what their home’s potential truly was. After various interventions, the home reached an outstanding performance level, achieving 9.3 Stars.

Alongside this high-performance was a home that reduced more than 60% of it’s heating, cooling and total energy demands compared to the compliance performance of 7.0 Stars.

The home achieves operational net-zero, with potential savings over $100,000 over 30 years.

Importantly, the home achieved resiliency in a changing environment, averaging 9.5 Stars across the various climate change scenarios up to 2050.

To summarise before diving into the data, this home achieves some outstanding outcomes that all contribute to a healthier, more comfortable, and more resilient home.

P.S., our favourite key takeaway was this: the (very close, and almost) complete elimination of both heating and cooling needs within their children’s bedrooms. To us, this is an incredible outcome, and shows just how incredible and valuable this process can be.

The Starting Point

Before our investigations being, we need to establish a baseline. This involves coordinating an initial home specification that is then built upon incrementally.

Sally had successfully integrated passive solar design features into the home; with plenty of northern glazing, minimal western glazing, and the garage and utility spaces placed strategically on the south-western corner of the home.

The home achieved an initial rating of 6.3 Stars, and after some minor interventions, achieved the first step of hitting compliance levels of 7.0 Stars.

Key Suggestions for Going Beyond Compliance

After investigating lots of different configurations, implementations, and strategies, the key suggestions that helped us go beyond compliance were:

Exposed concrete floors in a darker colour
High levels of insulation throughout
- Slab-edge: R1.0
- Walls: R4.0 to external walls, 140mm studs to the internal garage walls with R4.0, and R2.7 to the remaining internal walls
- Ceilings: R7.0 with heeled-trusses to enable insulation to all edges of the ceiling
Ventilated cavities in the walls, and roofs, with Class 4 Vapour Permeable Membranes
High-performance glazing (uPVC double-glazed) with light-coloured frames
Large, strategically placed ceiling fans in high-cooling demand spaces
Insulated and weatherstripped garage doors
2 window adjustments:
- Reducing a western facing window
- Splitting northern facing windows into Bed’s 2 and 3 to introduce some operability and ventilation

These suggestions resulted in a performance outcome of 9.3 Stars.

Influence of Airtightness on Thermal Performance

We can mimic how a Heat Recovery Ventilation (HRV) system influences the performance of the home by removing exhaust fans and the kitchen rangehood. In a non-regulatory simulation, we can also showcase the influence of airtightness on performance.

With no exhaust fans and a recirculating rangehood, and airtightness at 3.0 AC/H @ 50pa, the home achieves performance of 9.9 Stars.

Room by Room Comparison

From here, we showcase to Lauren and Scott the benefits of going beyond compliance. We stand back and let the data and insights do the talking.

**Figure 1:** Room Star Rating Enhancements

**Figure 2:** Comparison of Heating Loads

**Figure 3:** Comparison of Cooling Loads

The Human-Centred Benefits

**Figure 4:** Average Annual Internal Temperatures

The Transformation

The data doesn't just tell a story, it reveals a remarkable transformation.

Imagine: some rooms lagging in performance, now reaching perfect 10 Star performance. Even the most challenging space, Flex 1, soared from a mere 5 stars to an impressive 9.5, a dramatic shift powered by substantial reductions in heating and cooling demands.

But the true impact lies in the heart of the home. In the Kitchen and Living area, cooling needs were cut by over 75%, creating a haven of year-round comfort. But most importantly, the children's bedrooms. They achieved the impossible, a complete elimination of heating and cooling needs. A testament to future-ready design, this is what happens when architects and energy efficiency consultants unite.

These aren't just numbers; they're the building blocks of a healthier, more comfortable, and resilient home. This project demonstrates the power of collaboration and the tangible benefits of exploring early the energy efficiency performance of the design.

Imagine delivering a home to your clients where their family thrives. A home with comfortable temperatures year-round, lower energy bills, and a healthier environment for their children. That's the power of working with ARKATA.

As this case study demonstrates, our collaborative approach to energy-efficient design delivers exceptional results. By integrating sustainable strategies, we helped the homeowner’s Lauren and Scott, and their architect Sally, achieve a 9.3-star energy rating, creating a healthy, comfortable, and resilient home.

Ready to create future-ready homes for your clients?

Contact us today at 0431 922 265 to explore how we can help you create a home that is healthy, comfortable, and built to last.

A Case Study: Lauren & Scott’s Home