Why are Passive Houses so important?

Nowadays, Passive Houses take on special importance, since cities occupy only 3% of the planet earth and consume 75% of its resources, so it is imperative to combat CO2 emissions from urban centers. 


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The perfect property is one in which we feel “at home” – it provides comfort, health, is efficient and environmentally friendly, resulting in low energy costs and a tiny ecological footprint. This is the definition of Passive House.

This type of construction is adaptable to different climatic, cultural, and economic conditions, and is based primarily on the buildings’ high energy performance and indoor environmental quality, while at the same time being affordable and sustainable. 

In fact, a Passive House achieves high levels of energy efficiency and contributes to the health and comfort of its inhabitants, it is developed to be a healthy and sustainable dwelling, with maintenance and energy costs below those of a conventional building.

The Passive House concept was born in Germany (passivhaus house) in 1988 by Prof. Bo Adamson and Dr. Wolfgang Feist, who built the first passive building in Darmstadt in 1991 – 31 years later, the building is still as efficient as it was when it was built.

This type of building sets an international construction standard, focused on sustainability, where engineering and architecture come together to use available resources more intelligently, making the most of them.

The certification of this type of building is done by the Passivhaus Institut, which determines if the building meets all the requirements.

The 5 pillars of passive construction are:

  • Excellent insulation levels;
  • Reduction of thermal bridges;
  • Air tightness;
  • Ventilation systems with heat recovery;
  • Doors, windows and other efficient glazing.

There are approximately

Passive Houses em todo o mundo

Capital Gains of Passive Houses

In summary, compared to other buildings, a Passive House has better indoor air quality, higher thermal comfort levels, improved acoustic comfort levels, higher energy efficiency levels, and reduced CO2 emissions.

Quality of life and comfort

Good air quality and thermal comfort (minimum temperature 20ºC and maximum temperature 25ºC) and almost non-existent thermal variations.

Reduced costs

Lower operating costs, due to reduced energy and maintenance requirements.

Energy Efficiency

Energy savings reach 75% compared to conventional buildings and 90% compared to older buildings.

Healthy Building

Based on the principles of physics, it prevents the appearance of pathologies in buildings and optimizes their performance.


They drastically reduce CO2 emissions and contribute to climate protection, also by using renewable energies.

Interview with Joaquim Teixeira

We talked to engineer Joaquim Teixeira, a long-time partner in Metathesis projects, who gave us his opinion about the future of sustainable construction in Portugal and demystified several misconceptions about Passive Houses.

The world needs urgent answers to combat climate change. How can Passive Houses contribute to this more sustainable future?

Buildings are a major source of emissions and thermal inefficiencies, which can be solved by constructing buildings that consume as little energy as possible and also provide effective ventilation. 

Energy reductions from passive houses can be as high as 75% when compared to a new building built to current regulations, with these data it is irrefutable that passive houses contribute greatly to a more sustainable world.

The myth prevails that by opting for a passive house we give up the more personalized architecture…

It’s really a myth, because the choice of a Passive House does not condition architectural choices, does not require the choice of specific materials different from the usual ones on the market, nor does it require a specific construction method. In terms of appearance it is not possible to recognize a Passive House. 

There are also many people who believe that this type of construction is more expensive than traditional construction…

Another myth. By using resources intelligently it is often possible to build with the same investment as a standard building. In addition, there are small details that passive houses consider, which do not add any cost to the process, but only make it more efficient, such as, for example, defining a good orientation of the building allows optimizing the sun exposure.

What adjectives would you use to describe a passive house?

Comfort, health, economy and sustainability!