In the 80s, William Shurcliff, North American passive house pioneer, physicist and respected faculty member at Harvard, published a press release about this new technology – he was convinced passive houses held the secret to an entirely new form of energy.

Thus, the story of challenging the status quo of the energy biz as we know it and pushing the energy transition forward continued in the 90s. This time Europe picked up the baton.

Legend has it that in the early to mid-90s an American visitor graces the research project in Darmstadt, Germany and the two physicists meet. The American is enthusiastic about what he sees and leaves with the advice to no longer think of it as a research project but as a realistic solution to the climate crisis for the mass market. Who was this mysterious American visitor? None other than Amory Lovins of the Rocky Mountain Institute. He returns home and publishes the first ASHRAE paper on the topic of making passive buildings mainstream in 1995.

Inspired by the early North American pioneers, their work and the term “passive house” the German Passivhaus Institute or PHI was being established in 1996. The team starts on the mission that Amory left them with – what if "Passivhaus" could be popularized and made code? At this point, branding, lobbying and working to convince the industry of the high-performance business opportunity starts in earnest. The German industry steps up and invests in R&D to create the high-performance components necessary to meet the ambitious energy targets and to facilitate the envisioned large-scale deployment, just like Shurcliff predicted. This included smart vapor retarders, high-performance triple pane insulated windows, high efficiency ventilation systems and even the magic box, all micro-systems integrated into one appliance. PHI also begins to train the workforce in the design methodologies and techniques required to deliver such high performing buildings and promote professional certificates. Certifications of buildings, though still only in the hundreds in Germany, start to take off by the year 2000 and the group around the German Institute begins to attract attention from other European countries and the US. 

A new twist is added to the original definition: a Passivhaus is a building where the heat can be delivered through the low-flow balanced ventilation system needed for good indoor air quality in a home (and a separate heating system can be eliminated). That amount of heat is very tiny and is likened by some to the amount of a blow dryer. "How about you heat your house with a blow dryer?" is an early marketing pitch. People start paying attention. Could it be that buildings can be built in a way that they don’t need a heating system any longer?

Not everyone is happy about the proposal. HVAC equipment manufacturers are trying to figure out where to position themselves, and some push back against energy efficiency as they see it as a threat to their businesses. The industry leaders begin to heavily invest in large-scale heat pumps instead. A conflict starts brewing – technology is being pitched against conservation.

The established energy industries now lobby openly against “insane” high levels of efficiency and try to sell mechanical efficiency as the solution instead. Conspiracy theories are swirling around, like someone tried to run Dr. Feist off the street the other night when he was riding his bike home… he could only save himself by jumping into the bushes.  The heat pump industry is the suspect. Or the oil industry? All that just to say that Passivhaus was a tough sell. It did not go down without bruises and success did not come easy.

The Smith House, built by Phius Co-Founder & Executive Director Katrin Klingenberg, was the first passive house built in North America.

In 2002, I break ground on the first "Passivhaus" in an English-speaking country: the US. I soon find myself in a very different climate than central Europe. I am in the middle of the country. It is a continental climate with severe temperature deltas in summer and winter, and it is humid! Nevertheless, I experiment and apply the German-derived targets to see where it gets me. My ventilation integrated heating element, the proverbial blow dryer, "blows" – the relay melts during the first heating season during a two-week cloudy period with -20F degree temperatures in February. The actual peak, it turns out, was almost twice the 1 W/sqft target.  First lesson learned: in that climate, I had no chance to deliver the necessary heat just through the ventilation system. Additional heating, still very small, is necessary. 

In 2003, I attended my first Passivhaus Conference in Hamburg, Germany. One of the keynote speakers blows my mind. He is talking about “Passivhaus” and the design tool as a way to manage complexity… a lightbulb goes off in my head. At the end of the conference, I introduce myself to Dr. Feist. He says “where have you been? I have been waiting for you.” It turned out he had heard about my house (I’m not sure how). Over dinner, we become fast friends. I learn that he also has a degree in philosophy. That was really my dream, to become a physicist philosopher before I decided to become an architect. The conversation moves from technical details to big picture and the universe. 

As a result, I am invited to join the team at the Passivhaus Institut in Darmstadt to help on the first translation of the Passive House Planning Package (PHPP) into the English language. I am staying in a guest apartment in one of the first multifamily projects in Darmstadt. During my one-on-one training, I learn about the early North American pioneers. All the books I’ll later research and find and buy on my own, are already on Dr. Feist’s bookshelf. He says, “you did not know about the Building Research Council, the Lo-Cal house and the role of the University of Illinois Champaign-Urbana in all this when you built your house?” The look on my face at that moment must have been priceless – I am stunned, just beginning to grasp the serendipity of all this. I built my house a few miles away from the Building Research Council and the very first Lo-Cal house and I had no clue. 

Then he gives me a stack of monitoring reports and says, “here is the proof of concept for Germany…please give those to Amory Lovins.” I had never met Amory, but back home I got in my car and went on a road trip out West. I walked into the Rocky Mountain Institute, introduced myself to him and delivered the reports – but that is another story. 

At the time, no cooling targets yet exist in the standard, but people like myself are now starting to build in climates that do have cooling needs. In the next couple of years, the scientists at the Institute respond by adding a cooling target to fill that gap. It ends up being just a mirror image of the German heating target, 15 kWh/sqm.yr. I did not give it much thought at the time, but could it really be that simple? It wasn’t, but more on that at a later point.

Later in the 2000s, the design methodology starts to be tested in various countries across Europe and local interest groups form. PHI did a great job communicating to politicians and the public why we need significant energy savings technologies in the construction sector. And they stayed persistent. Something akin to a movement forms in Europe. 

Some groups stay closely connected with the German Institute, while others such as the Swiss decide to change the reference area of how the annual demand is calculated to their local convention. Minergie-P emerges as its own certification system with different targets. The Belgians also remain independent from the PHI but mostly keep the same targets. They do realize that building science, if widely applied to all building typologies, becomes a big deal when superinsulating. They add requirements for additional hourly and hygrothermal modeling to make sure there is no mold in buildings. They will be the first to succeed in making passive houses code in their country. They change the source energy criterion in the process to promote active solar generation. 

The very northern countries quickly run into the peak load problem like I did in central North America – they too have much bigger temperature extremes. They are the countries that first suggest increasing the peak load criterion to guide the design – as far as possible but not higher – to maintain the Shurcliff mini-mechanical system characteristic for resilience and passive survivability. They then let the annual consumption float up as needed. In the US, we will later look to them and be inspired by their thinking to help evolve the methodology for the varied North American climates. 

In either case, general momentum for “Passivhaus” has been created and it starts to ripple beyond borders, but also to unravel around the edges. Stay tuned for Part III as North America takes center stage in this passive house tale.