PROJECT FILES: When people hear the term high performance home, they often think first about insulation, glazing and energy efficiency. Those things matter, but on the South Coast of New South Wales, they are only part of the picture.
At Bombora, the bigger question was how to build a home that would stand up to the long-term realities of a coastal environment. Salt, moisture, wind-driven rain and material durability are not background issues here. They shape how a home should be detailed, built and protected over time.
That is what made Bombora such an important project for us. It is not a Passive House, and it should not be described as one. But it is absolutely a high-performance house — one that pushed us to think carefully about the building envelope, moisture management, durability and what quality coastal construction should look like in practice.
Building coastal
Located in Berrara on the NSW South Coast, Bombora is, in many ways, our best project to date. It brought together strong design ambition with the sort of technical and practical decisions that make a home perform well over the long term, not just look good on completion.
The vision was never about chasing a label. It was about delivering a home that responded properly to its location and would remain comfortable, durable and well-protected in a demanding coastal setting.
The build is currently estimated to cost around $1.95M. For this client, this will eventually be their forever home.
That meant looking beyond the visible finishes and spending real time on the parts of the project that many people never see once the home is complete. The wall build-ups, cavity design, moisture management strategy, sequencing and protection of the envelope all became central to how we approached the build.
To bring the home in line with the latest NCC requirements around moisture control and durability, we’ve allowed for a ventilated cavity system and upgraded roof build-up. This comes in at approximately 4 per cent of the overall build cost and is now considered best practice for long-term performance and compliance.
Building for coastal conditions
Coastal homes ask more of a building.
Salt-laden air, moisture and exposure can shorten the life of materials and create ongoing maintenance issues if the home is not detailed and built properly from the outset. A lot of builders can produce a house that photographs well on completion. The harder question is how that same house will perform after years of coastal exposure.
That is where Bombora sharpened our thinking.
The project reinforced a principle that now sits at the core of how we think about high-performance coastal building: if you are not paying close attention to what reaches the building envelope, how water is managed, and how moisture is controlled during construction, you are often building in future problems.
Why drainage cavities mattered
One of the key technical elements of the project was the use of drainage cavity construction.
This was not included as a trend or as an aesthetic talking point. It was a practical building-science response to coastal conditions.
The purpose of a drainage cavity is straightforward but important. It creates separation between the external cladding and the structure behind, giving any moisture that gets beyond the outer layer a path to drain away rather than becoming trapped in the wall assembly.
In coastal environments, where exposure to wind-driven rain and persistent moisture is part of the normal operating condition of the building, that layer of protection matters. It is one of those decisions that may never be noticed by the client day to day, but it contributes to the long-term durability of the home in a meaningful way.
For us, Bombora was not about creating a ventilated façade system. It was about getting the envelope strategy right in a practical, buildable way. The use of drainage cavities sat within a broader approach focused on moisture management, durability and protecting the home from the environmental pressures that come with coastal construction.
Moisture management during construction
One of the most important lessons on Bombora was that high performance is not just about the finished design. It is also about what happens during construction.
Before gyprocking the house, we ran a dehumidifier continuously for two weeks to pull excess moisture out of the internal air and reduce moisture levels within the timber frame.
That process made a real difference. We were able to bring the average timber moisture content down from around 20 per cent to 13 per cent before lining the house.
That is not the sort of decision that usually appears in project marketing, but it is exactly the sort of decision that affects how a building performs over time. Locking excessive moisture into a structure before lining can create problems later, whether through movement, instability, reduced material performance or a less robust internal environment.
For us, that part of the build is a clear example of what high-performance construction really means. It is not a single product or headline feature. It is a series of disciplined decisions that improve the quality and resilience of the finished home.
What worked on this project
What worked best on Bombora was the alignment between design ambition and construction response.
This was not a project where technical performance was treated as an optional extra. The envelope, cavity design and moisture management strategy were all approached as essential parts of the project. That gave the project a level of integrity that would not have been possible if those issues had been left as secondary considerations.
The project also reinforced how important sequencing and site discipline are in
high-performance work. Good drawings and good intentions are not enough on their own. The execution has to be consistent, and the trades need to understand why the details matter.
Bombora was a reminder that many of the most important outcomes in residential construction are driven by the quieter decisions behind the walls — not just the visible finishes at handover.
The business case for building this way
There is also a business case here, both for builders and for clients.
Some people still hear terms like building science, high performance or better envelope detailing and assume they automatically mean unnecessary complexity or cost. In reality, the bigger risk is often under detailing the project at the start and leaving the client exposed to future maintenance, durability and performance issues.
In coastal construction, especially, the cost of doing it properly upfront can be far less than the cost of addressing problems later.
Bombora reinforced that point for us. Better moisture management, sensible cavity design and greater care around the envelope are not abstract technical upgrades. They are practical decisions that support the long-term value of the home.
High performance without claiming Passive House
One of the reasons Bombora is an important project to talk about is that it sits in a useful middle ground.
The house is not Passive House certified, and it should not be represented as such. But it is still a clear example of a high-performance home. That distinction matters.
Not every client is seeking certification. Many simply want a better house — one that is more durable, more comfortable and better suited to its environment. Projects like Bombora show that there is real value in applying high performance thinking even when the project is not pursuing a formal standard.
That opens a broader conversation for the industry. We should be building more homes that perform substantially better than minimum compliance, especially in exposed coastal settings where the environmental demands on the building are obvious and ongoing.
Lessons from Bombora
The biggest lesson from Bombora is that high-performance construction starts long before the finishes go on.
It starts in the way the building is thought through, detailed and sequenced. It shows up in decisions around drainage cavities, in how moisture is managed before the house is lined up, and in the level of care taken to protect the envelope from the beginning.
The project was designed by Sean Lymbrey of Salt Building Design and engineered by Andrew D’Ambrosio of D’Ambrosio Consulting Structural Engineers. That collaboration mattered.
Projects like this rely on the designer, engineer and builder, all taking the coastal conditions seriously and resolving the details in a practical, buildable way.
For us, the project strengthened a view we now hold strongly: quality coastal building is not just about aesthetics. It is about durability, moisture management, envelope protection and building a home that is genuinely fit for the place.
Bombora stands out because it brought all of those ideas together in one project. It is a house we are proud of not only because of how it looks, but because of how it was built.
Materials and products
Bombora also brought together a number of products and materials that supported the wider performance and durability strategy of the project. The wall incorporated a Pro Clima weather resistive barrier system. Externally, the project used Hurfords Timber’s thermally modified merbau cladding — understood to be the first house in Australia to use the product. Pacific Teak features ceiling lining and a Colorbond roof, which were also used.
These choices were not about novelty. They were part of a broader attempt to balance durability, finish quality and suitability for a coastal environment.
Conclusion
Bombora helped clarify what high-performance residential building means in a coastal setting.
It is not about using buzzwords or making claims that do not fit the project. It is about making sensible, disciplined decisions that improve how a home performs over time.
On this project, that meant a strong focus on the building envelope, drainage cavity construction, and moisture management during the build itself — including the decision to run a dehumidifier for two weeks and reduce average timber moisture content from 20 per cent to 13 per cent before gyprocking.
Those are the kinds of decisions that do not always get seen, but they matter. And in many ways, they are what separate a house that simply looks good at handovers from one that is built properly for the long term.
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