3 minutos
According to the Royal Spanish Academy, being sustainable means staying for a long time without depleting resources or causing serious damage to the environment. Therefore, we tend to think that all sustainable products are good for the planet, but this is not always the case. Sustainability also has its dark side. And althought Pink Floyd or Yoda have talked a lot about dark sides, in this case we don’t have so much information.
We have been working for years for a more sustainable architecture, headed by the energy efficiency of our buildings: improvements in thermal envelopes and air conditioning installations, Nearly-Zero Energy Buildings (nZEB), Passivhaus standards, etc. Currently, and due to the pandemic, we must also improve certain aspects in buildings such as air and materials quality and the flexibility and adaptability of spaces. During all this time we have made great progress, generally measured by its economic impact (savings in heating and air conditioning) but also by its comfort (control of the inside temperature, air quality). But there are many more aspects to consider and we often have to juggle so that all the pieces fit together, forgetting (consciously or unconsciously) some of these issues in favour of others. And that’s when sustainability shows its dark side.
Despite our efforts to reduce energy demand, a recent UN report indicates that CO2 emissions from buildings operation reached their highest level in 2019, and alerts us to the urgency of decarbonizing the construction sector . Projects like #Building Life are already working on it, but how can these numbers be explained if we are reducing consumption and so our emissions?
One of the main problems, in addition to the CO2 produced during the use of buildings, is the embodied carbon. When we demolish a building and build another one in its place, we are wasting the carbon embedded in the original building whereas we are creating new emissions into the atmosphere with the production of the new materials used and the construction itself. And even in nZEB or Passivhaus-type buildings, these new emissions can take decades to compensate. According to The Royal Institute of Chartered Surveyors, 51% of the carbon emitted by a residential building (35% in the case of office use) is released before it is operational. Therefore, when demolishing the emission numbers might not be successful, which is why it is very important to consider energy refursbisment as the main option, whenever possible.
Embodied carbon enters the equation when we take into account the entire life cycle of the building, something we are not quite used to do yet. To do this, tools such as Life Cycle Analysis (LCA) and Environmental Product Declarations are useful to have an estimate of the energy cost of materials. It is clear that we cannot base our choice only on embodied carbon, but we cannot ignore it either. Because if to save emissions in 2050 we increase those of 2021, we might not reach our goal. Nor does it seem fair to wait for the current problem to be solved by our future selves, doesn’t it?
On the other hand, the wrong utilisation of the building (whether conscious or not) by its users is also related with the increase in emissions. Surely many of us have seen windows open in winter while the heating is at full power, closed micro-vents in windows, annuled gratings, etc. These small actions affect the overall behaviour of the building, so it is important that users know how it works to avoid energy losses.
Finally, greenwashing has also contributed to creating this dark side of architectural sustainability, using the prefix “eco” in vain and adding it to some materials that are not so it. Or placing vegetation without measure and just only for the sake of pplacing it. Or with various environmental certifications, whose scoring systems do not indicate the degree of real sustainability if they are not analyzed altogether.
Sustainability is a whole, and it is important to consider all aspects together, to obtain a balance and a good overall result. If we only deal with the lights, the shadows will appear when we least expect them.
