A Great New Guide to the Benefits of Passivhaus

It's about a whole lot more than just saving energy.

Child in Passivhaus window

Passivhaus Trust

Passivhaus is a hard sell. The building standard, often referred to as Passive House in English-speaking countries, was really an energy standard, and for most of the last decade, energy was cheap. I have tried to explain other benefits with posts, like "How Do You Sell the Idea of Passive House?," but many of the benefits of Passivhaus are invisible. It is hard to get people to pay for what I have called inconspicuous consumption.

Now the Passivhaus Trust (PHT), "an independent industry leading organization that promotes the adoption of Passivhaus in the UK," and knows how to spell it, is taking a shot at selling the concept with its guide to Passivhaus Benefits. The document appears to be directed to the authorities, builders, and owners rather than consumers, but the information is relevant to everyone.

What is Passivhaus?

Passivhaus or Passive House is a building concept where heat loss or gain through the walls, roof, and windows is drastically reduced by the use of insulation, high-quality windows, and careful sealing. It's called "passive" because much of the heating required is met through "passive" sources such as solar radiation or the heat emitted by occupants and technical appliances.

They are off to a fine start with the cover photo shown above. Passivhaus buildings often have much thicker walls because of the amount of insulation, and the triple-glazed windows are draft-free, so even on a cloudy day in winter, it can be a warm and comfy place to read.

Health and Wellbeing

Passivhaus Trust

That's why I always lead with comfort, health, and well-being. The PHT writes:

"Warmth and ventilation are the top building performance issues affecting health, but other indoor environmental factors can also make a big impact on health and wellbeing – for example, overheating, air pollution, and noise." I have always believed that this is the most effective message; people care about health and wellness, it is why the Well Certification system is eating everyone's lunch; it's personal. In a more recent post, How Do You Sell a Green Apartment Building Today?, I pitched Passivhaus and got an interesting comment: "By and large, people don't care about carbon or snail darters. They care about smiles, comfort, and security. Satisfying their own egos."

People do care about indoor air quality, and Passivhaus keeps the smoke and other pollutants out, as well as cutting noise transmission in half. Good controlled ventilation is also more important than ever.

As the PHT notes, "Since the Covid-19 epidemic, the dangers posed by under-ventilated buildings have gained fresh urgency. The problem is long-standing, and the implications reach further than the transmission of airborne viruses. All areas of human health and wellbeing are impacted: physical, mental, social, and even economic."

Mick Wooley in Window
Mick Wooley in Window of Larch Corner Passivhaus.

Mark Siddall

The window seat meme is effective, and not just with kids. That's Mick Woolley in the Larch Corner Passivhaus, designed by architect Mark Siddall and covered on Treehugger here.

Passivhaus window in Vienna
Passivhaus window in Vienna.

Lloyd Alter

Here is my contribution to Passivhaus window seat porn, seen in Vienna where it is made even deeper by building bookshelves. This could almost be a window bed, and would never be comfortable without the window quality that you get in Passivhaus. The message in all of these is clear: Passivhaus is cozy, even by the windows.

I have always thought that the health and well-being angle was the best approach for selling Passivhaus, but other messages are becoming more interesting and relevant.

Financial benefits

Passivhaus Trust

The lower energy bills that come with Passivhaus were always a tough sell because they used to cost significantly more to build and energy was relatively cheap; the energy savings never penciled out. However, over the years as building codes got tighter and builders got more familiar with Passivhaus construction, the difference in price has been diminishing.

Meanwhile, the price of energy has been spiking dramatically. In the United Kingdom, it is becoming a major crisis. Energy bills are becoming a serious problem and Passivhaus is looking very attractive. This is why I have asked: "Is it Payback Time for Passive House?"

Also, in an electrify everything world, the Passivhaus building can act as a thermal battery—you heat it or cool it when the electricity is cheaper and it will stay that way. And if the power goes out, people are safe and comfortable for a lot longer—days instead of hours.

The PHT explains in greater detail:

"In a typical building, there is a periodic heating cycle during the winter, with the house being warmed up when the occupants are awake and using the building, then cooling down at other times. It would be impossible to shift the timing of the heating system without the occupants noticing the cold. In contrast, even in winter, Passivhaus maintains a constant internal temperature night and day. The rate of cooling in a Passivhaus is so low that heating can be advanced or delayed by several hours without a significant impact on the internal temperature. This means that a Passivhaus can time its use of heating to coincide with cheaper electricity tariffs, which can offer significant savings."
Climate Emergency

Passivhaus Trust

The climate emergency has never been a great pitch for consumers, but Passivhaus is becoming more relevant every day in the face of the climate emergency. The problem with alternative strategies like net-zero or Saul Griffith's electrify everything mantra is that an electrical distribution system has to be designed for peak load, and the way you reduce peak load is with building efficiency. You also get more out of the system. As PHT notes:

"As well as reducing loads, a well-insulated building like a Passivhaus makes things easier for the grid because it can 'load shift'. In a Passivhaus, you can move the timing of heating energy use away from peak demand times, with minimal or no loss of comfort. Thus, when non-shiftable loads (eg for lighting and cooking) are at their highest, the heating in a Passivhaus can be turned off for several hours. Heating can even be ‘pre-charged’ when total demand, and therefore energy cost, is lower (eg during the afternoon)."

Seriously, so many people are pitching hydrogen and Small Modular Reactor fantasies to provide new clean energy supplies and save our climate, when the Passivhaus people know that we can do it by reducing demand with insulation, tape, and decent windows. This isn't hard. As the PHT notes:

  • Achieving net-zero on site is difficult—reducing demand to Passivhaus levels gives us the best chance of achieving it.
  • Achieving net-zero as a nation is also difficult. There will always be a finite amount of renewable energy. Our grid cannot deliver the peak power needed to heat our homes and hot water without slashing demand, and without demand flexibility. Passivhaus helps with both limitations.
  • It is more economical to save energy than it is to generate it.
Social Benefits

Passivhaus Trust

It's important to recognize that Passivhaus isn't just about houses, but also about community. The standard is being used for schools and offices and, as the PHT points out: "There are many interconnected social benefits from Passivhaus construction. These include better comfort and wellbeing, improved mental and physical health, education and skills attainments – which in turn may benefit the economy and society."

Neither can they be thought of in isolation, with many of our neighbors suffering from energy poverty and isolation because of the way we have designed those communities.

We also have the big problem that we have run out of time. That's why I do not have much room for the fist pumps for heat pumps crowd and none at all for the hydrogen hype types: We need proven solutions that work now for the renovation of what we have and new construction for what we need. The Passivhaus Benefits Guide makes it pretty clear which way to go and why; it may be written for the U.K. but is relevant anywhere.

Last word to the Passivhaus Trust:

"Overall, this study has shown that building to the Passivhaus standard in the UK is not only the most appropriate choice for delivering high quality buildings but also is the best choice for the environment and population at large. With rapidly rising climate anxiety among our children, it is our moral responsibility not just to the planet but to our children to act today. And what better way to show our society that we are acting on climate change than to radically transform the spaces where they live, work and play."