Improved building outcomes, such as greater levels of thermal comfort, a healthier work environment, lower energy costs and increased building structure longevity can all be achieved using the Passive House Building Standard.
While there a plenty of benefits associated with the standard there are still obstacles to overcome as Australia is still in the very early stages of the passive house journey.
Speaking at a workshop hosted by engineering and infrastructure advisory company, Aurecon and Monash University, industry experts said there is still a knowledge gap to overcome before the standard is normalised.
Until then the Passive House Building Standard will incur greater costs, according to Aurecon's ESD consultant, Johanna Trickett.
“However, the passive house benefits of user comfort and energy efficiency outweigh the costs,” she said.
“The Passive House Building Standard is applicable to any construction and provides a quality benchmark for health, comfort and performance.”
The building science manager at Pro Clima Australia, Jesse Clarke, said lack of compliance creates a range of building problems from moisture and mould in cooler climate locations, and exacerbated summer cooling issues in warmer climate locations.
“The Passive House Building Standard has solved both of these issues by delivering comfort through control over thermal fluxes over the building envelope, combined with adequate thermal bridging. This provides stability of indoor conditions,” Clarke said.
“Through air tightness considerations and implementation of the building standard, we see a balance in the moisture flows with the heat within the building envelope which results in a healthy, dry, high performing building.”
Aurecon associate, Susanne Hundert, said passive house construction required high levels of building fabric air tightness to provide the thermal comfort and low operating costs expected.
She said the key areas to consider with a passive house design is the building envelope and building services.
“Both the envelope and services must be carefully considered at the same time during the design process,” Hundert said.
“The responsibility of delivering a successful passive house sits with every project team member involved.
“It is crucial for everyone involved to be open and transparent to effectively work as a team.”
Fantech's intelligent ventilation solutions engineer, Joel Seagren, said a number of factors can contribute to improved health, enhanced IAQ and low contaminant levels and a significantly reduced need for supplementary heating and cooling.
“This reduces the risk of allergy and dehumidification effects that can be associated with HVAC air delivery systems,” he said.
“While ventilation requirements are well prescribed for some building classes, the importance of correct ventilation is increased as there can be no reliance on fresh air infiltration via the building fabric.
“While this is not explicitly included in the design, it can have a meaningful impact in terms of indoor air quality, condensation removal, and mould growth.”
Seagren said direct ventilation, mechanical or natural, increases the required capacity of heating and cooling equipment when outdoor air temperatures, or humidity levels, are outside comfort bands - which is typically most of summer and winter depending on the climate zone.
“With efficiencies in the 80-90% range for high quality heat recovery units, this could allow for a significant reduction in heating and cooling plant capacity, energy consumption, and therefore, operational costs,” he said.
An overview of the Passive House Building Standard, high performance building envelopes, airtightness, mechanical ventilation, and construction sequencing were among some of the topics discussed at the workshop.