Passive architecture: what homes with no heating or cooling and virtually no energy consumption look like

Heat waves, skyrocketing fuels…wherever you are in the world, heating or cooling a home is about to become more expensive and complicated.

In a few decades, parts of the Earth used to temperate climates will experience Very extreme weather. More heat, more air conditioning, which leads to more energy consumption, which contributes to global warming and translates into … more heat. A vicious circle in which we are already immersed and It condemns us to disaster.

However, there are solutions for constructing buildings that have a low environmental impact, such as using recyclable natural materials such as wood or soil, or Follow a series of guidelines that will drastically reduce energy consumption.

The latter is the so-called “passive housing” concept Use the building’s own architecture Keep them warm in the colder months and cooler in the hotter months, within reach Reduce energy consumption Up to 90%.

“Saving energy should not only be a user matter, but rather a technical one Can and should be resolved with elements of architecture and through technical know-how”, he explains BBC Bertolt KaufmannSenior Scientist passive house company, A German company that established a construction standard that spans the world today.

In other words, reducing energy consumption does not depend on lowering the thermostat. Whether we get warm in winter or warm in summer: architecture should and will help. Following a series of basic principles such as good insulation and so on A study of solar orientation and climate conditions of the environment, “passive houses”. A home’s energy footprint can be minimized.

Spanish architect Nacho Cordero, Trained in the concept of “passivehouse”., uses an analogy to explain it: “Imagine you’re going to build a boat, and the way to design it is to build a bilge pump so it doesn’t sink. Passive architecture is the opposite. A ship does not need a bilge pump or should attempt to have one only for emergencies. Basically, he points out, the idea is simple, “Trying to make things right”.

We usually associate ecological houses with spectacular and luxurious constructions, or indeed any house, whether located in dreamy locations. Even a bland suburban apartmentMay become a passive house.

Surely, there will be a building that meets their standards Very different in Iceland or Spain or Cuba. The concept and the underlying physical properties are maintained, but in a cold country, for example, Try to capture as much solar gain as possibleWhere the summer sun burns, Trying to create shaded areas.

However, they all have the same objective: to keep energy consumption to a minimum. “For new housing, the objective of passive houses is that they have a maximum of 15 kW per m2 per year and 25 renovated with these standards,” Kaufmann says. Taking into account that a typical house can use 150 to 300 kW per m2 per year, Saving is important.

Basically, passive architecture is understood as adapting to the climatic conditions of its surroundings, It has been since ancient times. Throughout history various peoples have sought to utilize the resources available in their environment, geographies and adapt Meteorology to build houses that provide them with acceptable comfort.

The mud houses of Mali, cool under the scorching sun of the Sahara, or the igloos dwellings of the indigenous people of the Arctic regions. static and passive.

with Invention of modern air conditioning and heating systems in the 20th centuryHowever, the architecture was largely detached from the climate around it. For example, even if it is a glass building in a sunny area, an air conditioner can keep the building cool. Heating boilers, gas or oil, even windows that don’t close properly can keep homes warm.

The The oil crisis of the 1970s However, put the concept of energy efficiency on the table Climate emergency It became a priority.

Since then, the concept of “passive houses” has become popular in architecture schools with the aim of reducing the energy impact of buildings. Although different projects emerged in the United States, Italy or Switzerland, the project established by the German Wolfgang Feist and the Swedish Bo Adamson in the late 1980s was practically completed. theirs The first “passivhaus” was built in 1991. Today thousands of buildings around the world have this certification.

Five basic principles govern Passive House quality.

Thermal insulation. Passive houses have better thermal insulation, which is three times higher than conventional buildings. “In cold climates you should use a 20 or 30 centimeter layer of insulation, although in temperate climates it doesn’t need to be that thick,” Kaufman explains. This protective layer around the house prevents both entry and loss of cold or heat.

Air tightness. Even if quality insulation is installed, if not sealed well, heat will escape through gaps and create uncomfortable drafts, losing energy efficiency. “passivhaus” takes into account the tightness of the buildings, for this, tests are carried out where the air is blown into the houses, checking where it is coming out and fixing it.

Quality houses and doors. A very significant part of the energy we use to heat the house escapes through the windows. Passive houses not only take maximum care of the orientation of house openings to utilize solar gains, but also use triple glazed windows to avoid heat loss as much as possible.

Reduction of thermal bridges. They are points where the insulating surface is broken (for example, by a nail or an aluminum window frame) and allows heat to escape into a building.

Ventilation system with heat recovery. When windows are opened for ventilation, heat is lost in winter and cool in summer. Passive houses have a mechanical ventilation system installed that filters the air and recovers the house’s own heat to heat the incoming air. There is no need to open windows in this system.

This standard is becoming more common in areas of the world such as European unionFrom where companies Near-zero energy consumption requires as much new construction as possibleGuidelines implemented in each country by its own regulations.

But, in general, many countries are trying to reduce the carbon footprint of new buildings. Sometimes, even with strike actions like attempted imposition New York Mayor Bill de BlasioIt proposed banning the construction of “incredibly inefficient classic glass and steel skyscrapers”.

The move didn’t move forward, but it got many people thinking about the relationship between architecture and climate change. For Kaufman, the proposal De Blasio makes a lot of sense: It’s not only greener, it’s cheaper. “30-50% glass surface is sufficient to get the required light. For example in an office building, Only the window area above desktops is usefulEverything below is not there, it will be very hot in the summer and the heat will be lost in the winter”, he reflects.

Any home can become a “passive home. Those already built to these standards are more efficient, but can be ” Renovate homes following the Passivhaus concept”, Kaufman assures.

“This is very common in the rehabilitation of entire buildings or single-family houses,” explains Cordero, although that does not mean that an apartment cannot be conditioned as much as possible to the “passivhaus” standard.

Obviously, invest in quality products Makes the construction process more expensive. “It’s a little more expensive, but not too expensive,” admits Kaufman. 5-6% more Building envelope cost. Other elements such as high quality windows also add to the final price.

“We count in whole numbers $100 extra per m2 “The habitable area of ​​a new construction, and some more for renovation, is 150-200 dollars per m2,” explains the expert.

Architect Cordero recognizes that this type of construction raises the price of the house, especially if you want to obtain certification from the Passivhaus Institute, a process that can be lengthy. “It’s not mandatory, but ultimately it’s a mark of quality“, explain.

Sealed or unsealed, the goal is the same: save energy. “Customers tell us they want a home that is maintenance-free. Energy hole. Ultimately it’s common sense: if you’re going to make a big investment, like building a house, It is preferable to spend a little more to build it, but then, month to month, it is still bearable.

And maintenance? In addition to the ventilation system, it is required Change the filters From time to time, residual maintenance is in conventional buildings.

Ultimately, Kaufman explains, It is thinking about the future. Passive architecture requires low power consumption Only use renewable energy, something that is not currently possible for conventional buildings. “That’s why we need to reduce their energy demand, because in the future we won’t have gas or other fossil energy sources.” A future, perhaps, not so distant.