The Passive House standard has slowly made its way around the globe, since its inception in the early 1990’s. Founded from research into the relationship between thermal comfort and low-energy passive design, the standard’s success is testament to the strength of concept.

Schools Infrastructure New South Wales have commissioned this report into the case for developing schools in NSW to the Passive House standard, using a recently built project as a prototype to test the concept against currently delivered construction. This report aims to establish the benefits of doing so, alongside the costs and risk, and to ascertain whether there is a rationale to further pursue this particular design approach as a means to enhance the offering of high quality, low-energy and healthy environments for children to learn. This report is a joint collaboration between Grün Consulting and Envirotecture.

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Context

Local building practices have suffered from complacency and a weak building code. Despite regulations calling for minimum levels of thermal performance, gaps in building physics knowledge, true implementation of design solutions and lack of enforcement have enabled both designers and builders to deliver underperforming buildings, to the detriment of occupants, building operators and the industry. Over time, the culture of acceptance of low building quality has become the norm, and the holistic cultural shift required to correct the industry has become overwhelming.

For example, the current building stock experiences:

  • high maintenance costs
  • low residual value and high rate of building replacement;
  • high running costs
  • poor indoor environment quality, including an epidemic of mould and dampness (Lane, 2018);
  • long-term health impacts on occupants;
  • increased strain on the public health sector, due to potentially avoidable or worsened conditions including respiratory and integumentary conditions
Nominated program outcomes - Cooler Classrooms (School Infrastructure NSW, 2019)

Nominated program outcomes – Cooler Classrooms (School Infrastructure NSW, 2019)

The NSW Government is committed to providing students with healthy and comfortable learning environments.

In 2018, the NSW Government announced a $500 million fund for the Cooler Classrooms program, specifically to provide air conditioning to schools.

The impetus of the program is not just around cooling, but to deliver heathier and comfortable learning environments, as is evident from the program announcements (School Infrastructure NSW, 2019).

The provision of air conditioning systems does not, in isolation, ensure good IEQ, and it is identified in the programme’s public messaging that the provision of fresh air, solar PV and occupant awareness measures may provide broader benefits.

The delivery of Passive House schools as part of the portfolio directly and effectively supports the above objectives, as well as providing resilient and robust assets with further benefits. Of particular note is the reduction in plant costs, including space requirements and capacity, and infrastructure costs, which may include substation upgrades or other infrastructure impacts.

Passive House Standard and Green Star - Design & As Built
Image showing NCC 2019 Update

Movement at the top end of the market (e.g. Green Star), and regulatory change at the minimum compliance (NCC BCA) end seem to be bringing us closer to a refined pathway.

We understand that the Government has also recently made a commitment to benchmarking projects, and potentially formally rating, against the Green Star rating system. A 4 Star rating has been nominated as the minimum standard for new projects.

In 2016, the Australian Passive House Association (APHA) announced a collaboration with the Green Building Council of Australia to streamline recognition of common design outcomes between tools. In a world-first, the Crosswalk now enables Passive House Certified projects to achieve up to 30 points (of a total 100) under a deemed-to-satisfy pathway in Green Star. With a 4 Star rating requiring 45 points, the approach could significantly streamline delivery.

Passive House in Health and Education

The international experience is that Passivhaus school buildings deliver excellent IEQ where students have greater support for learning activities, when directly compared to prior environments; the monitoring data tends to support subjective views. Early monitoring data from Australian schools shows comparable CO2 levels to the “conventional” schools in the chart below. We note that greater than 1,500 parts per million (ppm) is considered poor air quality, and begins to affect cognitive function.

Monitoring results and occupant feedback from UK Passivhaus schools (Hines, 2016)

Monitoring results and occupant feedback from UK Passivhaus schools (Hines, 2016)

We feel that our children are more alert and attentive in lessons due to the amount of
daylight in classrooms and the fresh air throughout the school. The fact that the new school
is built to Passivhaus standards means that learning has been enhanced. Our pupils are
comfortable, secure and stimulated buy their new environment; hence they learn very
well!

Sara Morris

Head Teacher, Oak Meadow Primary School (UK)

Evidence of broad scope studies have also shown that the direct cost of investment in Passivhaus measures can be more than recouped through reduced hospital admissions and social costs, in addition to the direct savings (Vidal, Guardian, 2013).

Want to know more?

Our report is available for download in the link below and also addresses the Cost and Benefits of Passive House and Implementation. Further, we release our feasibility assessment of a school in NSW, comparing documented construction against passive house construction along with outlining how to achieve a high performing thermal envelope.

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