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The case for passive homes as a national standard

Karuna House
Karuna House by Hammer & Hand. Image: Passive House Institute & Alliance U.S/Flickr

OPINION: The energy policies and building standards that govern our homes need to keep us comfortable and limit global warming. Passive house, a rigorous building standard for ultra-low energy buildings, ticks these boxes.

The coming months will see a state election in New South Wales, a federal election and a COAG Energy Council Meeting. In the lead up to these events, there will be a number of “hot” items on the agenda, namely the environment and the consequences for our communities living through a time when the climate is warming and is likely to warm ever more rapidly.

Housing, climate, sustainable development and our national policies towards these issues will have significant impact on our communities and environment in the coming decade. These issues are likely to dominate the next two election cycles and this period represents the majority of policy making time that we have left before the 2030 date that was so clearly put on the table by the Intergovernmental Panel on Climate Change to reduce the severity of environmental impacts to 1.5 degrees of warming. So, now is the time to get active on these issues to ensure the creation of proactive policy platforms that will guide our country and communities towards addressing these issues and create the impact and change we need. 

We have all noticed the rising temperatures and the records that are continually being broken across or country. We have also been told to expect rolling blackouts for our cities during heat waves and that this creates a platform for legitimising the debate for what some call “clean coal”. 

Looking deeper into the question of why we have such strong demand for energy leads us to the understanding that Australia has some of the largest and most inefficient houses in the world, that 80 per cent of the floor area built in this country is residential and that approximately 95 per cent of this floor area performs at less than 1.5 stars. 

Other questions to ask are: What exactly do our building codes and energy ratings measure, and how do they measure it? Are these measurements and rating tools evidence-based? Do they limit the amount of energy that can be used by a building? 

Did you know that more people die in their homes from heat stress than from any other natural disaster in Australia? This little-known fact has led me to ask some other serious questions. How are we protecting the most vulnerable members of our society? How are we addressing this issue for the future? What do our communities know more broadly about building performance, energy usage, the building code, how it preforms and how it can be used to protect us against climatic extremes as they become more frequent? What information is available to the general public that leads to genuine understanding of the importance of energy efficiency, good design and well-built buildings and the very serious impact they can have on their own health and well-being?

My search led me to the Australian Passive House Association and its vision to see “all Australians live and work in healthy, comfortable, low energy, resilient buildings”.

But what exactly is passive house? Passive house is a rigorous building standard for ultra-low energy buildings. The international passive house standard creates clear requirements in several areas of energy efficiency for a structure: annual heating and cooling demand, total primary energy consumption and air flow all must be at a very low level. With an in depth understanding of thermal physics in buildings applied early in the design stage, passive house achieves temperature stability through design, rather than through the use of appliances. This saves money for the residents on energy and air conditioning bills as well as drastically reducing the environmental impact of the building. 

In Norfolk, UK, for a small increase in upfront costs to build a home (5 per cent) people have enjoyed 90 per cent savings on their energy bills in subsequent years. In Australia, due to our lower temperature differentials, it is even easier to achieve the passive house standard and the cost premium is between 0-3 per cent.

Changing the way that we construct our living environment is now critical. The interconnected crises of climate, energy affordability, housing affordability and housing supply are becoming increasingly prominent in the public conscience. While significant scientific developments towards energy efficiency and sustainability are appearing in other sectors, building standards remain fairly unchanged. 

Accounting for 36 per cent of global final energy use and 39 per cent of energy related carbon dioxide emissions, the building and construction sector is a high impact sector that is ripe for climate mitigation. Rather than focusing on the source of energy without aiming to reduce its usage, passive house design aims to change the way we design buildings from the very beginning. Australia is expected to renew more than 50 per cent of its built environment by 2050, making now the ideal time to reassess our building standards and move away from outdated, inefficient and destructive building methods towards a sustainable, efficient and more comfortable way of living.

Nick Lane is the executive director and founding partner at Passive Place. In partnership with national industry non-profit the Australian Passive House Association, Passive Place is running the IceBox Challenge – a public science experiment which aims to tangibly reveal the benefits of passive house design and construction. The experiment will be run in Melbourne on the 22 February – 3 March at the Queen Victoria Market. 


Spinifex is an opinion column open to all, so called because it’s at the “spiky” end of sustainability. Spinifex may be inconvenient or annoying at times, but in fact, it’s highly resilient in a hostile environment and essential to nurturing biodiversity and holding the topsoil together. If you would like to contribute, we require 700+ words.  For a more detailed brief and style guide please email editorial@thefifthestate.com.au

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Comments

17 Responses to “The case for passive homes as a national standard”

  • Kim Wilkinson says:

    Hi
    I would like to take up the concept “low or virtually no bills”.
    I believe the ‘average’ house uses about 20 kWhr of energy per day.
    Accepted breakdown of this consumption has “heat&cooling” is about 40% of total usage. Other figures I have seen range from 20% to 50% (which is probably a better approach as it allows for the various climates in Oz). Others site a figure of about 40%.
    So if we use the 20% (used for “heat&cooling”) that is 4 kWhr (20% of 20 kWhr). This leaves 16 kWhr for other purposes.
    So if we use the 40% (used for “heat&cooling”) that is 8 kWhr (20% of 20 kWhr). This leaves 12 kWhr for other purposes.
    And if we use 50% (for “heat&cooling), that is 10 kWhr and leaves 10 kWhr for other purposes.
    The sort of improvement that a Passivhaus design is 90% of heating and cooling. Note: Passivhaus does NOT have any impact on the energy used for hot water, cooking, swimming pool/spa, retic pump, TV, computers etc.
    So when we apply the 90% reduction in “heating&cooling” results in the following:
    90% reduction of 20% used on “heating/cooling” leaves 16.4 kWhr.
    90% reduction of 40% used on “heating&cooling” leaves 12.8 kWhr
    90% reduction of 50% used on “heating&cooling” leaves 11 kWhr

    None of these results in “low or virtually no bills”.
    What leads to “low or virtually no bills” is installing PV (but that is a different discussion).

  • Ratko says:

    “Passive House” is not a misnomer but simply the English derivative of Passive House – translated for our benefite from Passiv Haus – really means passive building. Our Opera House, Parliament House, Jail house, Court house, Warehouse,…etc. aren’t “houses” either.
    Achieving low energy costs via Solar PV is nice, but if it means that people will build a poor structure, then fill it with Split A/C Systems to make it confortable and enough Solar PV to cover it – that is not an “Energy Efficient” building.
    A poor building propped up with efficient accessories is not the way to go. The resources sacrificed (dig the dirt up, process/transport/manufacture/ship/install/maintain/replace/dispose of….polluting all the way) to have those extra solar panels and a/c’s could be better utillsed elsewhere rather than in covering up the defficiencies of a dud home.
    Part of the reason a PH might cost more to build is that some of the materials needed are imported but still in low volume, and generally you could expect that prices will come down as usage went up. Similar for trades labour cost – the more mainstream it gets, the cheaper it will get.
    Better buildings – every passive aspect from the eaves to the floor insulation – is what we will eventually realise is the answer.

  • Andy Marlow says:

    Thanks Lawrence that was an interesting read.

    My take aways:

    ‘Robust’ means different things to different people.

    Occupant behaviour is influential on overheating in homes without mechanical cooling.

    In future climates (hotter) homes without mechanical cooling will be warmer. If they have greater levels of insulation they will be hotter than those with less. (Assumes outside is too warm to provide cooling AKA inner Sydney in December-February).

    The bigger the PV system the better the ROI looks and the better the CO2 numbers.

    My view:
    All Passive Houses in Sydney need mechanical cooling (we can discuss other places later). They’ll be small systems and you won’t use them much.
    In a 4 day heatwave nothing beats a great thermal envelope.
    The economics of PV mean that everyone now maximises their rooftop system. The NZEB status of the building is therefore dictated by heating and cooling only (everything else is the same regardless of thermal performance).

    I’ve been on a long journey to Passive House. Personally I’ve concluded that once you accept you need any artificial heating or cooling PH is the only logical way to build the envelope.
    Pure passive solar can still work, just not in that many places.

  • Lawrence says:

    Study in the Netherlands showing Passive House standard is less robust than other standards in the dimensions of overheating and CO2 emissions.

    https://www.researchgate.net/publication/324249219_Robust_net-zero_energy_buildings-A_methodology_for_designers_to_evaluate_robustness

  • sid 2.0 says:

    I’m mindful that discussions about what is the best low-zero energy housing standard can get “pointy” very quickly! But in an attempt to offend the least number of people as possible IMHO:

    1. There are many different standards and methodologies for assessing the energy performance of houses, all of which have their advantages, disadvantages, benefits and criticisms. I like to think of energy efficiency standards as being like different varieties of apples – they are all apples, and everyone will have their preference, but this doesn’t necessarily mean the other varieties are inferior.
    2. Being a performance-based code, the National Construction Code doesn’t prevent the use of Passivhaus for assessing the energy efficiency compliance of a house. Almost any standard or methodology can be used, as long as it meets performance requirement P2.6.1 and verification method V2.6.2.2 (or suitable equivalent). I’m pretty certain Passivhaus would have no problem with meeting these requirements!

    That’s my two cents worth 😉

  • John Moynihan says:

    Kim. Sorry, reading back over my comment re the costs of PH, I would be amazed if you understood it. It was poorly typed. My apologies. Hope you got the general gist of it.

  • Kim, I would agree that the costs are greater than 0-3%. These figures are true for Germany and most of the EU. I believe Australia could expect a figure closer to 15%. The main reason is the supply chain. We do not have enough activity here in Aus, YET, to have a mature supply system. However when you factor in the savings on the $30K ac unit and the benefits to living in a home that is comfortable all year round then I guess becomes a matter if the value proposition. Much like the 12-14k people at present people are paying for their kitchen benchtops.In reality it is obscenely expensive however it is one of the fastest growing business in construction.

    • Tina Perinotto says:

      and on marble benchtops …I just love the way that with anything enviro people always want to know the payback on investment but that question is never asked about the marble benchtop or foyer or the fabulous design elements and gorgeous furniture

  • Lawrence says:

    The question isn’t whether we should be improving the standard of buildings in Australia.

    The question is whether Passive House (Passivhaus) should be the national Australian standard.

    Study [Sameni et al. 2015] in the uk has shown houses built to the Passive House standard are at considerable risk of overheating and that 72% of monitored flats failed to operate as designed.

    Another known shortcoming is the requirement for space heating energy to use less than 15 kilowatt-hours per square meter of floor area per year. The additional insulation cost to reach this arbitrary target can be in the thousands (depending on climate) for energy savings that can be more cost effectively achieved by installing a solar panel. The Passive House standard performed poorly compared to other standards in a costs benefits study (sorry, can’t find source at the moment).

    The name of the standard itself “Passive House” is confusing and misleading, as it is in fact neither passive nor limited to houses.

    And would we not be effectively ceding control of our building standard to the Passive House Institute, a foreign entity?

    Not saying Passive Houses are bad; if you want to and can afford it, by all means go for it.

    But should Passive House be the national Australian standard based on current evidence – simply, no.

  • Comment to Peter(Skinner). Unfortunately Peter, you have failed to grasp Passive House and how it works. The description you provided, while accurate,fails to point out that PH encourages the opening of windows when the environment is benign and encourages people to close up when it is not. If we,and yes I am in Brisbane, had the idyllic climate you describe then people would not be installing air conditioners in record numbers. You failed to point out that the homes we are designing and building, including architects, who are some of the worst offenders, are porous colander like structures that experience up to 20 air changes an hour. Running conditioned air internally in these homes is similar to having gaping holes in your refrigerator. Passive House is not designed to interrupt the inside outside interaction when the ambient temperatures suit but rather to provide a similarly benign environment internally when its 35 degrees and 70% humidity outside or those 9 degree mornings in the most efficient way. You must have been out of town for January and February this year. Designing a home that can be so efficient as to heat or cool itself when required, on the energy equivalent of a electric kettle, can only be applauded in a carbon constrained environment. Happy to catch up and demonstrate how it really works. Worth noting one of the most rapid uptakes of PH in Europe is Spain and Portugal. These are among those fortunate areas of the world to referred to in your comment. Taking a Brexit like approach to PH,could be counter productive in the long run.

  • Kim says:

    hi all,
    Yes, I totally agree that most houses in Australia are poorly designed for the climate.
    Thanks Tim – I will read up on your suggested references.
    Some background: I live in Perth. Have opened my house for Sustainable House Day for the last 5 years. https://sustainablehouseday.com/house/wilkinsons-house/. It cost about $1200 / m2 (at the time). It costs very little for energy (electricity and gas). Yesterday about 7kW for the day with 3 adults living in the house. None of that was consumed for heating or cooling, in fact the largest single usage was to run the retic pump to water the garden. Last night I opened up the house and this morning it is a pleasant 22 degrees. Might rise to 24 degrees during the day. Air conditioning last used for one day during a hot spell about 10 days ago.

    The thing to remember is that NatHERS and Passive House are ONLY addressing the heating / cooling component of energy consumption (which is typically about 40% for the average household). Neither of them address the remaining 60% of energy used for hot water, appliances, cooking etc.

    The example of an house with a large electricity bill needs to be qualified by some information about the design of the house, number of people living there, does it have a swimming pool / spa, how many TVs are gong all day, etc..

    I have demonstrated that it is possible to build a house for not much more than the “project” rate and use modest amounts of energy. Passive Housing as per this article may be appropriate in certain parts of Australia (eg Tasmania and some parts of NSW/Vic) but I certainly don’t agree that it should be “the national standard”.

  • Mark Wilson says:

    I totally agree with Peter Skinner. I have designed a house that despite rating 6 stars (according to some questionable software) maintains a beautiful temperature range of between 15 and 25 degrees despite temperatures of between -4 and 40 degress with no mechanical or electrical ventilation or heating. It has a slow combustion fireplace but it never gets cold enough to turn it on. Most importantly the house has massive amounts of windows so you can see the distant views and feel the breezes.

  • Hi Kim, Australian peer evaluated studies on the cost to build better energy performing houses are a good starting point for answers to this question.

    Whaley & O’Leary ( 2017)

    https://apo.org.au/sites/default/files/resource-files/2017/03/apo-nid74464-1158961.pdf

    O’Leary & Belusko ( 2010)
    (https://epress.lib.uts.edu.au/journals/index.php/AJCEB/article/view/1584

    Moore, Berry & Moyse (2017)
    https://renew.org.au/sanctuary-magazine/ideas-advice/when-stars-align-finding-the-energy-star-rating-and-financial-sweet-spot/

    regards

    Tim

  • Peter Skinner says:

    Passivhaus principles are premised on disconnecting the interior of houses from the external environment, with a highly insulated impermeable envelope intended to maximise the efficiency of heating and cooling mechanisms. This is ideal in hot, cold and polluted environments where the energy expended to cool, heat or ventilate the internal environment needs to be reduced.
    In a few lucky places in the world, such as coastal south Queensland and northern NSW, the external environment is benign, even salubrious, for most of the year. As architects in these regions have shown, it is possible to design with passive techniques utilising solar gain and shelter in winter and shade and ventilation in summer, and a lifestyle that moves easily between inside and out through the year.
    Over-zealous reliance on the northern hemisphere strategies of sealed and super-insulated enclosures risks enforcing an indoor lifestyle on a region with a strong outdoor culture.
    It is true that our currently pleasant climate is rapidly worsening, but retreating indoors and installing air conditioning (no matter how efficient) is an act of surrender not resistance to climate change.

  • jesse long says:

    Hi Kim,
    What would you say would be a fair price increase? say if it wasn’t in fact under the 3% stated, maybe not 5%, 10% or even 20%.
    Globally we build to a shockingly poor build standard. The price we pay currently may well be 3%, 5%, 10% or even 20% more expensive than the poor quality product we are being offered to buy.
    The question needs to be re-framed in our heads -pricing should not be the main driver for building comfortable homes, schools and workplaces to one of the worlds best standards possible.

    • Tina Perinotto says:

      I think we need to factor in what low or virtually no bills can mean over the life of the house. And maybe include retrofitting of poor work. Not sure what standard typical house and land packages achieve these days but we know that hundreds of thousands of people might be sorry they were seduced by the open plan, no eaves, poorly insulated project homes that look good on the surface but fail to do their job of keeping people comfortable, without massive energy bills. I heard from an owner in Sydney whose energy bills are around $3000 each quarter. I bet his house cost less than an equivalent size passive house to build.

  • Kim says:

    Hi Nick,
    I notice that you have again stated that the increase in costs for a passive house would be between 0 and 3 percent.
    Can you please provide independent costings of a passive house to support this statement.
    The reason that I ask, is I believe the cost to to MUCH larger than 0 – 3 %

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