The Unseen Enemy: Why Water Management Comes First
You can build the most energy-efficient Passive House imaginable, but if you don't properly manage water and ventilation, you've built a home that is destined to fail. The reality is simple: water kills buildings. Proper water management and controlled ventilation are the non-negotiable foundations of any durable, healthy, and comfortable home.
We’re constantly told to focus on insulation, R-values, and energy efficiency. These things are important, but they come second to keeping water out. As a builder, you must approach roofs with three things in mind: stopping bulk water from getting in, providing a drainage path for moisture, and ventilating the space to allow for drying.
Traditional building practices often fail to address condensation, and products like anticon and silver sarking can be ineffective. Silver sarking is a great example of a misleading material; it’s a vapour barrier with holes punched in it, which means water can easily make its way back into the structure. This encourages condensation, dampens insulation, and promotes mould growth, negatively impacting indoor air quality and structural integrity. The effectiveness of reflective foil sarking is also significantly reduced if it's in direct contact with other materials, making its R-value worthless.
Building with durable materials is only one part of the story; the real key is effective water management. This includes draining water away from the building, managing it inside the building, and using proper waterproofing methods in wet areas and proper site drainage. at Carland Constructions, we exclusively use membranes from Proclima, which we consider the best insurance policy you can buy for your home. Water-resistant barriers (WRBs) like these are critical because they provide a non-absorptive drainage path for water and are designed to let the structure dry.
The stakes are high. Water ingress and moisture damage are major issues in residential buildings in Victoria. Insurance data from 2018-2021 found that water damage incidents accounted for 24% of all home insurance claims in Australia, with the average claim costing around $5,000. But the cost isn't just financial. Water damage and mould are directly linked to health issues, particularly respiratory conditions like asthma and wheezing in children.
The Only House That Should Breathe Is You
The phrase "a house needs to breathe" is one of the most misleading and dangerous concepts in construction. A building doesn't breathe like a living organism; it needs controlled and strategic ventilation. Without an airtight home, you cannot control the flow or quality of the air inside. The idea that a home relies on leaks for "fresh air" is flawed, as these leaks are a highway for dust, pollen, and pollutants.
This is why mechanical ventilation is a non-negotiable for us. Poor indoor air quality and mould are linked to sick building syndrome, which can cause general fatigue and respiratory difficulties. Mechanical ventilation systems, particularly those with heat recovery (HRV), are crucial for controlling moisture in the air and preventing the conditions that lead to mould growth. A well-designed system ensures a consistent air exchange, filtering out airborne contaminants and preventing moisture buildup. We believe that you can't call a home high-performance or sustainable without a proper mechanical ventilation system.
The benefits of mechanical ventilation extend beyond health. Research shows that good indoor air quality can enhance cognitive function and productivity. In addition, by controlling the air and moisture in your home, you're creating a more comfortable living environment that costs less to run.
The Takeaway
We are passionate about Passive House Melbourne and building to the highest standards because we know that it's the right way to build. However, this is only possible if we first master the fundamentals of building science: managing water and controlling ventilation. These are the pillars on which all our projects are built. You can build a home that is an Oscar-worthy masterpiece, but if you neglect these crucial, hidden details, it's nothing more than a pretty face. We take extreme pride in what goes on behind the walls, and that's the real story of a home that is built to last.
We have the runs on the board and the experience to execute a truly high-performing home. We love working on projects that challenge us and push the boundaries of what's possible. If you're looking for a builder who is passionate about delivering a home that is built responsibly and simply built better, look no further. We are a Certified Passive House builder Melbourne that is committed to building homes that just feel better.