Relying on Mechanical Ventilation has its Drawbacks
Modern New Zealand building standards are pushing for a more airtight building envelope to improve energy efficiency. While this is a step in the right direction, it has created a dependency on mechanical systems that come with their own set of drawbacks.
Instead of relying on a machine to keep your home healthy, we believe a smarter, more reliable solution lies in building a high-performance home that can breathe naturally. Here’s why a home built to a target of 2.6 - 3.0 Air Changes per Hour (ACH), with a vapour-permeable wall system, is a better choice for your family's health and your wallet.
The Mechanical Trap: Relying on a Machine has its Drawbacks
To meet targets for airtightness, many builders must install mechanical ventilation systems (like heat recovery or positive pressure systems) to prevent homes from becoming "sick." A very airtight home (often below 2.0 ACH) traps moisture and pollutants, which leads to condensation, mould, and poor air quality. The mechanical system becomes a non-negotiable solution to a problem created by the building method itself.
The natural Solution: A breathable. High-Performance Home
Instead of creating a sealed box that needs a machine to be healthy, we build homes with a vapour-permeable (breathable) wall system. This means we use materials and techniques that are slightly less airtight than the most stringent targets, aiming for an optimal 2.6 - 3.0 ACH.
This specific level of airtightness is key. It's significantly tighter than a typical older New Zealand home (which can be over 5.0 ACH), giving you excellent thermal performance and preventing cold draughts. However, the use of breathable materials allows the walls to passively regulate moisture.
Here’s why this is a superior, long-term solution:
Moisture Management: Our walls are like your skin—they can expel water vapour. This prevents the build-up of condensation within the wall cavities and on interior surfaces, eliminating the risk of mould and mildew without a machine.
No Dependency, No Running Costs: The health of your home doesn't rely on electricity or a fan and if there’s a significant power outage, your home will be fine. No noise, maintenance, or running costs.
A Healthier Indoor Environment: By allowing moisture and pollutants to escape naturally, you create a constantly refreshed and healthy indoor environment. This helps to eliminate allergens and Volatile Organic Compounds (VOCs), which can be trapped in sealed homes.
Choosing a home with a breathable envelope and a balanced airtightness level gives you the best of both worlds: superior energy efficiency and a genuinely healthy living environment, all without the ongoing costs, maintenance, and noise of a mechanical system. It's a more reliable and sustainable way to build a home for the future.
