HPH040 : Is the Passivhaus Standard a World Standard? – with Martin Holladay from Green Building Advisor (Passive House)


Martin Holladay from Green Building Advisor talks about the pros and cons of the Passivhaus standard. He also explains why he believes the German standard is not the best approach for the North American climate.


Interview with Martin Holladay

Martin Holladay is a senior editor at Green Building Advisor and Fine Homebuilding magazine, and he reports on topics relating to energy-efficient residential construction. 

He started out as a builder and remodeler, building single family homes, additions and renovations in Northern Vermont in the United States.

About 15 years ago he got into publishing, first as an editor at the Journal of Light Construction and then later at Energy Design Update.  

House-built-in-1974 Martin built his first house in 1974

Martin’s First House was a Learning House

Martin describes the first house he built for himself and how it followed passive solar principles. It was not an airtight construction though.

He calls this a ‘classic hippy house’ in the sense that it was thrown together with found materials and inexpensive items that he picked up from the dump.


The Solar Years

Martin explains some of the history of how green building advanced through the years.

As early as the 1940s, MIT researchers were looking at different ways of collecting solar energy.

Active solar systems used pumps and blowers as well as some mechanism for storing solar heat.

Martins says: “If it was a solar air system the heat was usually stored in a rock bin, usually in the basement which was literally a large bin of rocks through which heated air would be blown. Then the air would later be blown through the rocks on a cold night and some of the heat would be gathered up that way or more commonly in large tanks of water. And solar collectors on the roof, water collectors or air collectors would – with means of pumps or blowers – transfer this heat to the storage system.”


Passive Solar Homes

Passive solar houses aimed to use the design of the house to maximise solar gain and not use pumps or blowers.

With most of the windows on the south side of the house and fewer on the north, Martin says these houses heated up quite nicely on a clear sunny day.

There were drawbacks though. They lost a tremendous amount of heat on cold winter nights because of the large amounts of south facing glazing. So they had the reputation of being uncomfortably hot on sunny days and uncomfortably cold at night!

Saskatchewan-Conservation-House The Saskatchewan Conservation House was built in 1977

The Saskatchewan Conservation House was a Breakthrough

Instead of just gathering solar energy, this house also experimented with super insulation. So it was a house that was built on airtight principles and was tested at about 0.6 air changes per hour at 50 pascals.

It had R40 walls, R60 ceilings and used triple-glazed windows. Clearly these types of specifications have been recommended ever since in cold northern climates (for super insulated houses).

In 1985 The Superinsulated Home Book (affiliate link) was released and a whole movement advocating super insulated houses took off.


The Traditional Approach to Passive Solar Home Design was Abandoned or Modified

Martin explains that at this stage there were two opposing views of the best way to build a low energy house.

“The traditional passive solar people thought that you could get there by collecting lots of energy and the super insulation people thought that collection of energy was not really the issue. The issue was building a tight enough envelope that you didn’t lose energy and on balance I think the super insulated group has been proven correct and a lot of the early ideas of so-called solar house design have long since been abandoned or modified.”


The Passivhaus Standard Requires Cold Climate Builders to Invest in an Extraordinary Amount of Insulation

Martin believes that the goals for annual energy use required by the Passivhaus standard – the most famous of which is 15 kWh per mper year – are fairly arbitrary.

He continues: “By pegging an energy budget on the standard he [Dr Feist] required cold climate builders to invest an extraordinary amount of money in insulation that will never foreseeably be recovered in any possible energy savings.

“When true believers in the US started copying the Germans using the Central European standard in our climates they were ending up with 14 inches of rigid foam under their concrete slabs, they were ending up with R100 insulation in their attics and they were sometimes paying $6,000 or $10,000 for reducing tiny amounts of annual energy use that could easily have been supplied by a $400 solar panel producing electricity. It was this kind of absurdity that created a backlash in North America.”

For this reason Martin says the Passivhaus standard has no global validity.

Cellulose insulation Cellulose insulation

The More Insulation You Use, The Less Effective it Becomes

Insulating infinitely does not make sense, so there will be a point where it is no longer cost effective.

For example, doubling the thickness of the insulation will cut the heat loss in half, but each time it’s doubled it’ll mean spending more and saving less energy.

We can only estimate how much to spend on insulation.

Martin explains: “You guess at the lifespan of the building, you guess future energy costs, you put a dollar figure on the amount of energy you will pay over the lifetime of the building and you try not to spend more on insulation than will ever be saved in energy.”


Global Warming Mitigation Efforts Need to be Cost Effective

While it could be argued that very thick insulation saves the planet, if this is only includes houses for the wealthy – that are extraordinarily expensive – this is probably not a wise investment.

Money should be focussed where it has the greatest potential to reduce CO2 levels.


Passivhaus is Not a Religion

While Martin praises the Passivhaus standard for focussing on the right things, he says it’s not a religion and it shouldn’t be blindly followed.

He also hopes that it doesn’t become enshrined into building codes because it takes away flexibility from builders. 


There Needs to be a Massive Investment in Renewable Energy

In order to preserve the planet for our kids, it is a must that we become free of fossil fuels.

This means a huge investment in photovoltaic arrays, wind turbines, tidal energy (to some extent) and so on.


Local Communities Need to Embrace Renewable Energy

Martin is troubled by the fact that in the US it is becoming increasingly difficult to site renewable energy installations.

This is because local interests oppose wind turbines and in some cases PV installations as well because they are afraid that it will be a blot on the landscape. Unfortunately this comes at a time when we need to be moving at a faster pace, not a slower pace.


Efficient New Homes Alone Will Not Impact Our Climate Crisis

The timetable for building new homes is an entirely different timetable from the one required by our climate crisis.

Martin stresses we have to get a handle on this crisis within the next 10 or 15 years, or we are very much in trouble.

So building new super insulated homes does not address this issue. It is weatherization (or retrofitting) of existing homes that will be most significant.

There are clearly many other things that could be done outside construction. 


Listener Questions

1. Juraj Mikurcik asked, “What’s the biggest barrier in the uptake of large-scale, multi family Passivhaus in the US?”

2. David Cummings asked,”What are your thoughts on the marriage between natural building and Passivhaus and embodied energy?”

3. Thomas Langley asked, “Is it better to pay the extra money to go all the way to Passivhaus standard or do as builders all recommend and compromise on airtightness to save money?”



Download a transcript of the interview with Martin Holladay.


Our Question for the Comments Section

Is getting Passivhaus certification important for your project?



New York, New York – Las Vegas

Back From New Media Expo

I’ve been in the United States on a business trip to attend New Media Expo. It was very worthwhile and I met some amazing people who are also trying to change the world for the better with their blogs, podcasts and online videos. Unfortunately at the end of the conference, perhaps due to information overload and a lack of sleep, I had a psychotic episode and ended up in hospital.

Although I want to tell you this story (if you’re interested) I did not feel that the House Planning Help Podcast was the right place to do it. Luckily, Ellory Wells, invited me onto his podcast and I shared the tale with him.


My Empty Flight Back from Las Vegas

I said in the introduction to this podcast that I was shocked by how few people were on my plane travelling between Las Vegas and London Gatwick. Here is the proof! This photo was taken in the air and has not been doctored.


There must be a better way of organising flights so that planes are always at capacity?


Please Connect With Me

About The Author

Ben Adam-Smith is the owner of Regen Media, a UK production company that specialises in creating video and audio for the construction industry. He is also researching what homes we should be building in the 21st century and his personal goal is to build or renovate a property before he turns 40 in August 2016.

  • Jeremy Chandanais

    Good content. I am pleased to see a progression of renewable and passive energy supplementation into the housing industry! Think smart and know the cut off limits.

    • http://www.houseplanninghelp.com/ Ben Adam-Smith

      Thanks Jeremy. I’m glad you found it interesting.

  • Ron Marsh

    This was a very important podcast, which should now be followed up with further research to see how the applicable points apply to the UK.
    I felt that Martin played down the “faults” in the Passivhaus standard by blaming his local US states’ climate as being different to Europe. The truth is there to be found, because it is my research into the possibilities of doing a retrofit that have completely failed due to the cost benefit calculations.
    If it is true that a Passivhaus can *actually* be built for 5% more than a regular house, then that 5% can easily be clawed back in savings over the next few years. If, however, as in the majority of UK housing, people would like to improve their efficiencies as far as possible, BUT in a cost effective nature, then some of the experts out there need to focus on a solution which IS affordable. Doing this would actually create work for these people, while at the same time improving the climate issues we have.
    As I keep saying, a straight Passivhaus retrofit is a waste of money (if you have it to waste) and is therefore dead in the water, left to the rich, housing associations, and a few bad case refurbishments.
    This podcast is a breath of fresh air, and is the gateway to solving the UK housing/climate/fuel poverty problems. If only our clever designers and builders would realise it.
    Come on experts, come up with a realistic UK retrofit model, and make some money. The gap between “space age” and “sensible” needs to be bridged.
    Passivhaus is not a religion. Don’t sell your soul to it, but use the existing knowledge, products, and PHPP to solve the retrofit problems that we have.
    The basics haven’t changed since Martin started out. I studied solar, wind, water harvesting and biogas systems back in 1975, and they haven’t changed much either. We had an energy crisis then too. But this one, is much, much worse.

    • http://www.houseplanninghelp.com/ Ben Adam-Smith

      That’s a really interesting comment, Ron. Somehow I don’t think the learning is going to stop!

      I agree with you about retrofitting and the financial side of things just doesn’t seem to add up. This also concerns me as someone who is likely to do a retrofit as my first project! I don’t want to be pouring money down the drain – I just can’t afford to do that.

      However, our experts are up against it, too! The pressure is on and from my limited time of looking into this, there are no easy answers. Front-loading our bills is also gambling, because we have no idea what tomorrow brings.

      Anyway, I’ll keep the podcasts coming and try to dig deeper!

      • Perry525

        I enjoy reading Martin’s articles, but one has to keep them in
        perspective, he is after all a journalist and his job is to introduce
        the same repetitive articles over and over, each time with a new
        angle. He also introduces companies, products, people and encourages us to buy and to buy his magazine.

        Passive House is a good product, but our builders are not
        interested, PH requires diligent people who understand the importance of the work they are doing, it requires time and patience to get it right, our builders seem to be in a perpetual hurry and they cut corners, on the basis that most customers will never know what’s missing or has been done wrong. That is why the BRE found it so difficult to build to PH standards and why our government have scrapped the 2016 requirement.

        The first law of thermodynamics is that heat moves to cold, yet
        most of our current building and nearly all of our existing stock
        have been built by people who have gone for quick easy build ignoring heat flow.

        Every day we use Thermos flasks, these are as near to the perfect
        room as we can get, they have a draft proof, water vapour proof inner wall, with a sealed vacuum surround, their only heat loss is through the neck and stopper. Nevertheless they work exceedingly well. Unfortunately we cannot as yet buy room sized and shaped Thermos flasks.

        Our nearest reasonably priced equivalent is polystyrene sheet, but
        this needs to be fitted on the inside of every room – insulating
        the rooms warm air from the heat absorbing and heat loosing walls, floor and ceiling. Our current practice of placing insulation in the middle of the wall, or the outside, allows our expensive heat to
        escape. Yet companies like Celotex make the ideal products to
        restrict heat flow and loss through walls, ceilings and floors,
        after all heat flows through solids in all directions, not only
        straight through but down into the ground and up into the sky.

        • http://www.houseplanninghelp.com/ Ben Adam-Smith

          Hi Perry,

          I’m not sure whether Martin was being controversial for the sake of it, but I’d like to think he’s basing his comments on the science. Very few things in life are perfect and I think that the Passivhaus standard goes a long way towards where we should be heading in the future with our buildings. I also like the fact that it is a complete method – for example it doesn’t delude people into making their houses airtight at the expense of forgetting about ventilation.

          It is sad about the UK government but I think changes to the way we have to build are coming one way or another.

  • Lindsey Davis

    Interesting discussion Ben. It threw up some points I have been mulling over with regards to eco building principles in general e.g.we need to look at every project in context rather than follow a certain eco principle to the T.
    As he said, super insulating is all well and good but we only need to insulate to the level demanded by our own climate rather than follow a certain spec else we are wasting money and resources on materials.
    Also he mentions straw bale, which again has been validated as a eco-friendly and productive method. But has anyone worked out the required straw volume to land ratio that we should follow before it becomes more detrimental than an alternative build method? Would make for useful research.
    What I’m saying is that maybe the formula for any eco build should be: eco principle X + contextual variables Y and Z…(climate, house size, etc).

    • http://www.houseplanninghelp.com/ Ben Adam-Smith

      Thanks Lindsey. I am first to admit that I haven’t fully got my head around the issue but I’ll keep trying!

      I love the super insulation approach from the point of view that it uses a very small amount of heat energy once the building is in operation. However, if it’s cost a fortune and is not making sensible use of insulation as a material, then that’s not good. I would question whether these buildings have optimised designs though.

      It does seem like all these issues come back to striking a balance. As clients we have to make decisions at some point!

      At the back of my mind is still this thought that there are now too many people on the planet. I’m sorry to say it but I’d love to see our populations decline via education! I know it’s not that simple.

      • Lindsey Davis

        Sir David Attenborough would second that thought!

        You are right though, building eco houses is commendable and should be encouraged, but we can’t ignore that issues of sustainability go much deeper than questions of insulation, solar gain and triple glazing!

        • http://www.houseplanninghelp.com/ Ben Adam-Smith

          Well said!

  • Alan Clarke

    Interesting to hear Martin’s experiences in his climate, and I agree the “15kWh” is arbitrary (I hear even the Passivhaus Institute now realise it only makes sense in the European climate).
    We have other examples where a client asks us to specify a Passivhaus, and we’ve ended up saying “that’s not sensible”. One case is a couple wanting to build a 45m2 retirement bungalow at the end of their garden (yes, 480 sq ft). With such a small building the surface area to floor area ratio just don’t work in PHPP. But then with 2 people in that size dwelling, retired, so in the house most days, time to cook proper food – we could see the internal heat gains would be plenty to heat the place with “normal” passivhaus U-values, even if that came out as 30+kWh in PHPP, and this could be built for their modest budget.
    That said I am sold on the principles of Passivhaus – which I see as basically applying some rigorous physics to the issue of building heat loss, and have written a bit more about here: http://www.aecb.net/what-makes-a-passivhaus/

    • http://www.houseplanninghelp.com/ Ben Adam-Smith

      Alan, thank you so much for sharing this information. It’s really good to hear that this sort of conversation goes on because I wasn’t aware of it. Also, for some reason I was under the impression that the Passivhaus standard’s goals (such as 15kWh per m2 per year) were optimum points. Does that just mean in the European climate?

  • Mark Tiramani

    I hope no one is actually saying the 15kWh are “..based on random choice or personal whim, rather than any reason or system..” 😉

    Unfortunately http://www.aecb.net has lost your article Alan. All the “soapbox” links are broken :(

    The 15kWh is anything but arbitrary. i.e. it is not based on either random choice or personal whim, but it is based on systematic reasoning.

    But 15kWh was a choice, more or less because it is the mid-point between 10 and 20: 10kWh being too costly/difficult/extreme for many locations, and 20kWh being too unambitious. The criteria were arrived at over time as a consequence of combining physics with an environmental/financial cost-benefit analysis (it is here that the climate and cultural influences of northern Europe may have played a role).

    Passivhaus criteria were also set with the expectation that future advances in technology would enable those criteria to be met even in very cold climates. An example are PHI certifications in 2013 for frames and glazing that, as the PHI states “..are suitable for use in regions like in Northern Scandinavia,”.

    The other pass/fail number (Specific Heating Load) is 10kWh. This number is also not arbitrary. The limiting factor here is how much ventilation air can be heated before dust in the system starts to burn. Making the Heating Load criteria dependant on supply-air heating is another discussion though…

    Yes, the numbers were chosen in Europe, largely by Europeans, so whatever thermodynamic or “comfort” arguments are used, and however neutral one endeavours to be, there are inevitable geographical, cultural and socioeconomic influences. Although that certainly does not make the criteria arbitrary.

    “Is the Passivhaus Standard a World Standard?”, de facto no, but the physics are standard universal physics. It is a model and assessment method that is globally applicable. Human behaviour determines the rest.

    Should passivhaus be adopted into the UK building regulations? Yes, it should be adopted now as an alternative proof of Part L fulfilment. It’s an order of magnitude better than anything else we use in the UK. Part L is hopelessly disjointed and confused. SAP produces a sailing ship but no ropes to secure or trim the sails, and then insists you put in a diesel engine anyway.

    Would I have built Y Foel in its current form in northern Vermont? I doubt it. This is where I have to say achieving passivhaus certification with our design was (with hindsight) relatively easy in Wales. As things stand I do not envy Martin & Co. with about 5,000 heating degree days to contend with in northern Vermont. But ask me again in 5-10 years, then maybe?

    In this discussion new build and retrofit were somewhat confused. Although EnerPHit is the PHI take on retrofit it is far more likely to be uneconomic for a specific building than the passivhaus method is for new builds. I’d really like to see a clear separation between the two in public discussions. It must confuse the hell out of potential low-energy builders taking their first steps.

    Sometimes I wish we could simply refer to passivhaus buildings as PHPP-optimised buildings.

    • http://www.houseplanninghelp.com/ Ben Adam-Smith

      Hi Mark, it’s fantastic to have you on the blog! Thank you for leaving such an in-depth comment. I have little to add.

      I do not, however, quite understand what you mean by how this discussion confused new build and retrofit. I think retrofit (weatherization in the US) was only mentioned in passing at the end of the interview as to where the real effort needs to be. We’re all aware that it’s a massive financial risk to upgrade an existing house to EnerPHit standard. Ron Marsh wrote an interesting blog post on why the numbers just don’t add up – http://www.houseplanninghelp.com/passivhaus-retrofit-is-it-worth-it/
      Anyway, hopefully retrofitting will become cheaper in time.

      • Mark Tiramani

        Firstly: More of these podcasts please! I’m still hooked on audio and video. Reading is such an effort…

        I’m probably overly concerned that confusion may arrise in the mind of a reader making an early reconnaissance trip into the complex world of low-energy building. I just like to keep passivhaus new-build and deep retrofit in separate discussions.

        However, I agree completely that the billions should go into retrofit, whether specifically EnerPHit or not I cannot judge. In my ideal world all UK new builds should be passihaus now, and very urgent research should lead to a massive retrofit programme starting in a year or two. Dream on…

        • http://www.houseplanninghelp.com/ Ben Adam-Smith

          Thanks for clarifying that, Mark. And trust me, I’m really working hard on how I can create more content like this! I love doing this.

  • Mark Tiramani

    I just found Alan Clarke’s 2013 AECB soapbox article I mention in my post:
    “What Makes a Passivhaus?”