The main characteristic of sustainable homes is that “all consumption depends on natural sources, so their carbon footprint is practically non-existent,” explain the Vía Célere experts. It is one of the leading real estate companies in innovation and sustainability. Two years ago, this developer wanted to go one step further: not only to include energy saving criteria in housing, but also to measure the environmental impact of the construction itself.
Sustainable houses in urban environments
When we hear about sustainable houses, we may tend to think of a detached house surrounded by nature. In reality, it is in cities that the great battle for sustainability will be fought. Carlos Valdés, head of RSC at Vía Célere, explains the need to join forces: “It is important that those of us who are key players in cities can weave alliances to contribute knowledge and make progress on these challenges”. But are there sufficient grounds?
Measuring the environmental impact of construction
Measuring for change. This is one of the objectives of the Observatory for the Environmental Sustainability of Residential Building, promoted by Vía Célere, the Autonomous University of Madrid and the UAM Foundation. The observatory has already presented its second study (pdf): an estimation of the carbon footprint of a residential development. The conclusion is that “every square metre built in residential construction accounts for 441 kg of CO2 eq.” 70% of emissions are a consequence of the extraction and manufacturing processes of steel and cement, while the construction process generates 4.4% of the total. A magnitude that is hard to imagine.
Let’s talk about cars and trees
Data is best assimilated when it is about something familiar to us. The sustainable housing development that was the subject of the study – located in Villaverde, Madrid – emitted 6,809 tonnes of CO2. How to translate it into more understandable language? “Taking as a reference the emissions of 120 grams of CO2 per kilometre travelled by an average car, the total distance it could travel would be close to 57 million kilometres, i.e. more than 4,400 times around the world”. How many trees would need to be planted to offset this pollution? The study assumes that an adult tree retains half a tonne of CO2 after one year, and states: “To compensate for all the emissions generated in one year, about 13,600 trees could be planted”.
An event with a “footprint”
The presentation of the results brought together several organisations interested in sustainable houses and urban sustainability. It took place at the COTEC Foundation, which promotes innovation in our country, with the participation of Forética and the Spanish Climate Change Office. In this context, the attendees were able to find out how much they had polluted on their way to the foundation. The mobility tool of GreeMko, which has been collaborating with Vía Célere for years, was used. The other trace of the event cannot be measured: the one it left on each of those present.