Passive house - features, design and construction

Passive house is a concept, a standard in construction that, if respected, certifies that the building constructed is truly energy efficient, comfortable, affordable and environmentally friendly at the same time. It sounds complicated, a bit too technical at first glance, but it is simple to understand and apply at the same time.

The first passive house

It all started with Wolfgang Feist who built the first passive house with his family. That would be the short version.

Dr Wolfgang Feist is a physicist. In 1987, in a conversation with his Swedish colleague Bo Adamson, he learned that unheated houses were being built in China and referred to them as passive houses. In Sweden, too, there was a concern about energy-efficient houses. They decided to investigate whether the concept could be applied and work in Europe, where winters are colder.

At the request of the mayor of Darmstadt/Germany - a city that had a piece of land already available for the construction of experimental houses - Wolfgang Feist and his family decided to build this passive house.

Don't imagine it was easy. There were plenty of voices who didn't believe such a project was possible. Plus the technologies didn't exist and there was a lot of reluctance to innovate in this way on the part of the manufacturing companies. One happy case was the making of windows. At that time there was no triple glazing concept, now standard for a passive house. The head of the research team at Vegla (now Saint Gobain) agreed to supply this type of window for this project. But it wasn't always so. It took years for the industry to see the opportunities in this area.

In the first two years after completion, their house (more like a complex of houses) was visited by about 5000 curious visitors. Wolfgang Feist has shown that it can be done. Since then things have developed a lot, and Darmstadt has been the home of Passivhaus Institute (founded in 1996 by the same Wolfgang Feist) - an institute that was to play a very important role in the development of the concept - companies started to invest more in research and that's how we got to where we are today.

But things continue to evolve, with techniques getting better every day. In a conversation with Lehel Elek-Lukacs from Naturalpaint, a company dealing with the distribution of natural building products in Romania, told me that in Germany there is a concern for testing and comparing data on the use of traditional insulation materials (e.g. basaltic wool, polystyrene) with the use of natural ones (e.g. jute insulation or hempIn addition to technical performance, the air composition and its influence on health is also analysed. I will come back to this topic.

A passive house is more than just a low-energy building.

Passive houses save up to 90% in heating and cooling energy compared to traditional houses and over 75% compared to new construction. Similar energy savings have been demonstrated in hot areas where buildings require more energy for cooling than heating.
Passive houses are also praised for their high level of comfort. It uses the body heat of the inhabitants or the solar heat entering the building as an energy source inside the building. This makes heating much easier and saves a lot of energy.
Adequate windows with good insulation, insulated exterior walls, insulated roof and floor, all keep heat in the house during winter.
A ventilation system constantly supplies fresh air for superior air quality without causing unpleasant draughts. A highly efficient heat recovery unit allows the heat contained in the exhaust air to be reused.

Passive house is comfortable

The passive house provides maximum comfort during both cold and warm months, with reasonable construction costs - a fact confirmed by passive house residents.

Another important principle is 'design without thermal bridges', i.e. insulation is designed so that there are no 'weak points' around the whole building, all to eliminate heat loss. This method is another key principle that ensures a high level of quality and comfort in Passive House buildings, while preventing damage from moisture build-up.

Passive house is environmentally friendly and contributes to a sustainable existence

Passive houses are green by definition. They use extremely little primary energy with minimal environmental damage, leaving enough energy resources for future generations. The extra energy needed for their construction (embodied energy) is insignificant compared to the energy saved later. It is worth noting, however, that the Passive House standard offers this level of sustainability for anyone wishing to build a new building or renovate an older building at an affordable price - a contribution to environmental protection.

Passive houses are not expensive

Passive houses not only save money in the long run, but they're also affordable, experts say. The investment in high-quality building components required by the Passive House Standard is mitigated by eliminating expensive heating and cooling systems. Additional financial support from governments, increasingly available in many countries, makes building a passive house more feasible. Perhaps Romania should also adopt programmes to encourage passive house building. The benefits are enormous.

Passive houses are versatile

Experts say that any competent architect can design a passive house. By combining the client's wishes with the technical requirements, any new building, anywhere in the world, can be designed to reach the passive house standard. This standard is also increasingly used for non-residential buildings such as administrative buildings and schools. Education on the design of this type of building is available globally, with plenty of professional trainers ready to help at any time.

You have to see it to believe it

So says a Romanian saying and probably this is the idea of The International Passive House Open Days, in a rough translation. At this event, organised by International Passive House Association (IPHA)hundreds of owners of such houses open their doors to the curious to see for themselves the advantages of living in a passive house.

Passive house design in Romania

At Expo Construct I met Vlad Ciobanu, certified passive house designer. His company, Zecaph ConsultThe aim is to help those who want to build or rehabilitate any type of building to passive house standard. In addition to the specific services of design, energy efficiency, site supervision, I was attracted by the services of thermography diagnosis, quality control by thermal imaging and sealing testing by Blower Door. These are tests they perform to diagnose, quantify, control and remediate energy losses. With such technologies it becomes even more obvious that a passive house is more energy efficient with 90% than a traditional house. Below is a video by Zecaph Consult. Vlad and I arranged to go together to some of the houses they are working on to watch live tests and working procedures.

Another way you can have your own passive house is to call a passive house manufacturer. Obviously we recommend wood and wooden houses. There are manufacturers who, in addition to building your passive house, also offer you passive house design or certification. For example, professionals from Dimmer attended the specialised courses of the German Passive House Institute in Darmstadt and obtained the Passive House Tradesperson certificate. So you can be sure that you will end up with a Passive House when you call on them.

Until 2016, Dimmer built timber frame houses only in countries like Italy, Switzerland, Germany, France, Belgium, Spain, Denmark. Since 2017 they have turned their attention to Romania. In order to survive on the Western European market, where they competed with companies with over 100 years of tradition in timber frame construction, they were forced to build to a very high standard of quality, a standard they aim to develop for the houses built in Romania.

In fact, talking to Ionel Merlușcă, general manager of Dimmer, I noticed a great concern on their part to promote the passive house concept in Romania and the advantages of building such a house. We discussed their concern for the environment which led them to put great emphasis on energy efficiency. A very well known project in which they also participated is Buhnici House, a project in which the well-known ProTV media man George Buhnici built such a house.

Buhnici House is the first house in Romania and the 9th worldwide to be "Certified Passive House Premium". "The Passive House Institute decided to present the certificate to George Buhnici at this year's Passive House Conference in Muchen, and the certificate was presented to him by Dr. Wolfgang Feist himself. In the database of houses with Passive House certificates, George Buhnici's house is in next link.

If you've come this far in reading it means you're really interested in the subject. You are not alone. So am I. I'll stop here with the promise that, for you and for myself, I'll return to this topic, trying to further explore and promote the concept of the passive house.