Our next Big Debate will poke the hornet’s nest. Is Passive House the ideal solution for future fit buildings? Or will it create unliveable houses with occupants who forget to open windows, forget to change the filters on the low energy mechanical ventilation heat recovery (MVHR) and find mould everywhere?
- Coming up on 26 May. Buy tickets here.
Maybe close enough is good enough. Or classic solar passive design, where you ideally orient the building and take advantage of breezes that cool you down, as in classic Queenslanders.
If we can still get them.
If the temperatures outside don’t get hotter than those inside (which of course is already happening)
So here’s the thing, The Fifth Estate is off to Canberra on Friday to moderate a session for the Planning Institute of Australia, and one of the unforgettable nuggets of insight that came forth during the intensive discussion (yes, we are deeply challenged and in awe of the talent that will be on show here) was this simple comment:
All the good sites have been taken.
This needs to sink in.
Cinderella is no longer a thing. Developers in today’s world don’t get the magic dust sprinkled upon them as they seek their next apartment site. There is no glass slipper that will open the vortex to ocean views and cooling breezes, unless, of course, they have a bunch of well-heeled buyers snapping at their heels, happy to pay squillions for the privilege.
Developers trying to pump out housing for the ordinary folk in life need to work really hard if they want to deliver a viable and affordable product that doesn’t land them in court or the insolvency unit of a big four accountant when the construction fails or their reputation tanks.
But imagine that the housing was delivered by a long term investor such as the institutional owner of a build-to-rent block of apartments.
These dudes are in it for the long term. They have global investors who – believe it or not – still care about their ESG. And need to report to governments and shareholders about the climate risks of their financial exposures.
So, the product has to stack up: not just for the capital investment angle, but the operational angle that needs to be minimised.
In social housing, it’s the same. As Julian Sutherland, one of the panellists in our debate, told us in our briefing, in the UK, the authorities that build social housing are well aware that a Passive House is an excellent way to minimise the costs of thermal failure, bad health from bad indoor air and – yes, remove the risk of mould.
PH means you build housing on the sites that “John West” rejects. Noisy, polluted, shitty sites next to busy highways or – soon maybe – data centres and hyperscalers since these beasts of our cyber burdens insist on being as close to population densities as possible.
And that’s before we get to the climate.
As someone said the other day, there are places north of Brisbane where no one in their right mind would open the windows to the hot, humid air outside.
The reality is most houses today are not built as lazy roomy Queenslanders with ridiculously generous wrap around verandahs – (and of course we’d love one!), but instead we get brick and slab on ground, fully airconditioned.
About that.
The grid is not going to be greened anytime soon, especially if we open our doors to Sam Altman and the other crazies from San Fran who really want to recreate the world in a way they fully control – and need the world’s entire store of energy to do it.
So no, we can’t afford to stop caring about energy efficiency and thermal comfort and we particularly can’t not care about our indoor air quality.
The thing about our Passive House debate is that all the panellists will be in furious agreement about creating better, more resilient housing.
How? is the big question.
How far to go? is the next.
How much to spend is, of course, the issue that will be uppermost in most clients’ minds.
At BVN, our hosts for the night, and their talented architects, are on the case, skilling up in PH and gently testing the waters with clients.
Adrian Taylor, the company’s regenerative lead, who’s on the panel, says it’s a delicate game.
The team knows it’s the “high water mark” for quality building performance. Clients often love the concept but typically are not keen on paying for it.
Some want to go most of the way towards PH but pull back on details. In one such property, the team did a post occupancy evaluation on a “part-PH: house and found the home performed really well in terms of needing no heating at all in winter, but that in summer it overheated.
Taylor says a “few contributing factors” were unearthed: namely, that the standard was not correctly followed, including a lack of sufficient insulation. It happens – when construction starts, the cuts to quality get going.
On the panel, too, will be Andy Marlow of Envirotecture, who has been a certified PH designer since 2017
Marlow isn’t interested in myth busting, though. He just wants to share the benefits of PH as he sees them.
His biggest argument is that the indoor quality of housing or other buildings needs to be at least as good as outdoors because we spend 90 per cent of our time indoors.
Ouch… that stat alone is sufficient to make us question the quality of our indoor air, a concern that we know is rising fast in the list of priorities voiced by industry leaders such as the Green Building Council.
Here’s what Marlow sees as ideal in a house: one that is “cosy, free of dust, allergens, pollen, mould and mildew and improves health, mentally and physically.”
Yet we put up with much inferior products in our homes, he says, “because we think it’s normal. It doesn’t have to be.”
“There’s this perception that these things are expensive and only for the elite. That is not how it should be.”
His business is intent on changing those perceptions, he says.
On the more sceptical side of the debate will be Richard Hyde of the University of Sydney who has been deeply involved with passive solar design and does not see the need for full PH design in warmer climates.
The 2008 book that he published Bioclimatic Houses, Innovative Designs for Warm Climates, included a detailed study of a house on the Gold Coast that was considered to be particularly healthy and sustainable.
It was rated at a mere 4.5 stars NatHERS despite needing no additional energy for cooling and relying on only natural ventilation – something that at the time was not considered as a positive contribution to the rating.
Hyde also worked on the well known Currumbin Ecovillage on the Gold Coast hinterland, where houses were designed, again to passive solar principles.
One Queensland energy minister was so impressed, he launched a swathe of pilot projects around the state built to these principles, Hyde tells us.
It’s in another of his books, Climate Responsive Design, which he wrote after coming back to Australia after stints in Singapore and the United States, that Hyde delves deep into the concept of climate matching, where the form of the building must match the climate in which it was built.
Hyde questions why a German designed PH designed for German conditions has been brought to Australia instead of
starting with basic ideas of climate-matched houses here and then working from there.
“We should put that [version of] passive house in a box and say ok let’s build a really good Australian version or Australian passive design.”
The idea is that each house needs to be narrowed down from climate to microclimates, and then buildings need to be designed according to each site.
Hyde is now working on a paper with Ché Wall, who spoke at The Fifth Estate’s Codes Red event on related work.