What is Passive House?
You might’ve heard about it through the grapevine and wondered — what exactly is Passive House? Although more common in Victoria, Passive House design and construction is gaining traction in New South Wales, and the Illawarra in particular, as homeowners are craving energy-efficient, comfortable, and sustainable living experiences.
What is Passive House?
Originating in Germany in the 1990s, Passive House (Passivhaus) is a rigorous and science-backed building standard that focusses on creating highly energy-efficient and comfortable living spaces.
This design and construction approach aims to maintain a consistent indoor temperature between 20-25°C year-round while using significantly less energy* (less than 15 kWh per sqm of indoor space, per year) for heating and cooling compared to conventional buildings.
The concept has gained popularity worldwide, including in Australia, as homeowners seek sustainable and cost-effective housing solutions that offer superior comfort and indoor air quality.
*(It’s important to note that there are many people who cite a popular statistic that Passive House buildings can be up to 90% more efficient than its traditional counterpart. However, this statistic is very specific to tests run in Germany and as such, we don’t have specific data about how much energy is saved on average in Australian homes.)
The 5 principles of Passive House
So how do you know if a building is Passive House or not?
There are five key principles that form the foundation of Passive House design. These are:
Airtightness to prevent unwanted air leakage and energy loss (maximum 0.6 ACH)
High levels of continuous thermal insulation in walls, roofs, and floors
Passive House certified mechanical ventilation with heat recovery for fresh air and energy efficiency
Passive House certified double or triple-glazed windows
Thermal bridge-free construction to eliminate heat escape points
These elements work together as a system to create an extremely energy-efficient building envelope that maintains a comfortable indoor climate with minimal heating and cooling needs.
The airtight construction and ventilation system also provide superior indoor air quality by reducing pollutants and allergens.
Keen to learn more specifics about the technical criteria? Check it out here.
Image credit: Passivhaus Institut
The Passive House certification process
One of our favourite aspects of Passive House is the accountability that inherently exists in order to ensure a building meets the Passive House standard or not.
In order for a home to be considered a Passive House, it must undergo a rigorous certification process to ensure the building meets strict energy efficiency and comfort standards.
The certification process typically begins by engaging a Certified Passive House Designer or Consultant as part of your design team early in the project.
This professional uses specialised energy modelling software (called Passive House Planning Package, or PHPP for short) to inform design decisions and verify that the building will meet Passive House requirements.
The certification itself is carried out by accredited Passive House Certifiers who receive ongoing as-built documentation provided by the builder. They meticulously check the building's design, construction, and performance.
Key elements assessed include testing the airtightness of the building envelope with a blower door test and ensuring the correct materials have been properly installed (like the MHRV and insulation).
Successful certification provides assurance that the building achieves the stringent quality and energy efficiency standards of the Passive House Institute, and gives homeowners the peace of mind knowing their home is working in their favour, not against.
Why build a Passive House in Wollongong?
One of the biggest misconceptions we hear is that Wollongong’s climate is mild enough to not warrant Passive House standards.
The truth is, Passive House is the highest design and construction standard that exists, and it is incomparably better than the Australian Standard (which is the bare minimum for a home to be legal).
And because Passive House is such a bespoke standard of building, every home in every climate can benefit from Passive House in one way or another.
In a Wollongong summer, Passive Houses can maintain a cool interior without excessive air conditioning, while in winter, they retain heat effectively, reducing the need for additional heating. They also maintain consistent humidity levels (no more sticky floors!) and 24/7 fresh, filtered air. Not to mention the health benefits associated with living in a Passive House to begin with.
This climate-responsive design is particularly beneficial for Wollongong homeowners, as it addresses the region's seasonal temperature variations and helps mitigate the effects of occasional extreme weather events.
How to Get Started with Passive House
If you're excited by the idea of building or renovating your home to Passive House standards, here are some steps to help you get started:
Research and Learn: Start by reading more about Passive House principles and benefits. Websites like YourHome and The Australian Passivhaus Association offer valuable insights into passive design and its applications in Australia.
Consult with Experts: Reach out to local Passive House builders, architects and designers. At Amity Builders we’re happy to connect you with some of our favourite designers and architects who specialise in Passive House. We’re also always up for a chat to see if we might be the right Passive House certified builder for you.
Visit a Passive House: Experience the benefits firsthand by visiting a Passive House. The Australian Passivhaus Association hosts International Passivhaus Open Days a few times a year where you can visit homes at different stages of construction. Here’s our recap from the June ‘24 event.
Hi, we’re Amity Builders
We’re a passionate bunch who are tired of seeing homeowners around Australia settle for subpar living conditions. We combine our love for building, building science, and building relationships to create healthy, comfortable, and energy efficient living experiences for people. We’d love to get to know you!
