New Energy in Architecture

Should we express kWh on a facade?

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Only recently I have become acutely aware of the expectations that architects have regarding  the energy transition. It was during a presentation before the commission of a residential project that our office was working on. We explained that the building had been designed with the criteria of energy efficiency: natural ventilation for the dwellings and parking, along with a connection to a district heating and cooling network. It also included zero-emissions installations such as photovoltaics on the roof, batteries for energy storage and parking places equipped for electric charging. At that point, some of the commission members came up with questions regarding whether the ambitious approach that we had envisaged in terms of the innovative energy management of the dwellings was also expressed through the aesthetics of the project.

“So the energy transition should be visible on the facade,” I realized, and the suggestion seemed legitimate to me in a way, and made me think …

Rewind to 2015. Our office was collaborating on the Green Energy Central of Olot, from where a series of buildings in the historic center of the city (elderly residences, museum, market, administrative offices, and so on) received all their climatization and hot water from 100% renewable energy sources. Never before had I learned so much about renewable energies and energy management as I did through the excellent engineers that we were working with. They were all driven by a desire to create feasible alternatives for the use of fossil fuels. Technologically there were no serious problems for the project. The local and clean generation of energy through PV, geothermal and biomass could hardly be considered innovative. What made the project innovative was its complexity: the tangible implementation on a large scale within an existing urban fabric, and the fact that the project incorporated multiple aspects of the roadmap that should lead us towards a zero-carbon society.

In the first place, the energy sources were diverse and adapted to the specific needs at specific moments: hot water from biomass for sanitary uses during the morning and the evening; cold water from geothermal for climatization in summer; and hot water from geothermal for climatization in winter. At the same time, energy was generated locally, in a decentralized way, within a distance of 600 m from the users. And most importantly, all energy sources were renewable, so a serious amount of CO2 emissions, 750 tons/year, would be avoided.

As the architects of the Central, our task was to fit all the installations and machinery on the ground floor and basement of a former hospital. Frankly, this was not the hardest part of the project but rather a gratifying opportunity, considering that the rehabilitation of old buildings is also urgent from a sustainability point of view. But the real pioneering heroes of this project were the engineers who, in spite of all the difficulties they encountered, realized this zero-emissions energy network.

As a participant I could see up close how they dealt with the problems that had to be overcome to do something innovative, something not foreseen by current regulation. I saw how complicated it is to operate outside of the dominant fossil fuel system; how difficult it is to break through a status quo that has resisted until today, in spite of all the technological advances that have been made since the 70s, and in spite of the urgency of ongoing global warming. I became aware of these and many other things concerning energy and I think that after having worked on the Central, our architecture evolved thanks to the knowledge that was acquired then.

Moveable blinds can define facades ... they have to make sense though. Photo © B01 Arquitectes
Moveable blinds can define facades … they have to make sense though. Photo © B01 Arquitectes

Fast forward to 2020 and the questions that arose about the appearance of our dwellings. Does the energy transition define a specific set of aesthetics? On the other hand, is such a specific set of aesthetics required or even desirable?

We have seen architectonic projects that have achieved serious progress on energy management, and we have seen buildings that are completely contaminating from an energy/CO2 point of view. And I have to admit that I personally find it difficult to distinguish one from the other on sight. At least my experience is that the outer image of a building is almost completely disassociated from its inner functioning and its energy aspects. Of course there are elements that can indicate that attention has been paid to energy management: for example, cantilevers and moveable blinds that protect windows from excessive solar radiation; or the placement of photovoltaics on a facade.

Rigorous accumulative sun and shade analysis define parameters for architectonic design. Photo © B01 Arquitectes
Rigorous accumulative sun and shade analysis define parameters for architectonic design. Photo © B01 Arquitectes

But sometimes these are applied without much rigor and they end up being little more than a fig leaf. What I learned in Olot is that the most important step towards zero-emissions buildings is a serious collaboration between a rigorously sustainable engineer and a rigorously sustainable architect. But beyond that, the image or style of a building is not conditioned by sustainable energy concepts. Also the facade of the Olot Central had not suffered from restrictions in this sense.

Sustainable construction and the integration of sustainable energy in architecture is complex. In spite of what one might think, a big well-insulated sliding window, which is correctly oriented might very well represent an energy-efficient solution for a certain project. Energy is like so many aspects of architecture: whether it is good or bad depends on the specific situation and the context. Thus I think we should not only accept, but even feel comfortable with the fact that energy-efficient architecture might be unrecognizable. Let’s consider ourselves blessed that the energy transition does not limit architectonic expression.

Main image: The facade of the Green Energy Central of Olot, on the ground floor of the former hospital. Photo © Antonio Navarro Wijkmark

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