In November 2016, Emmanuelle Cosse, the then Minister for Housing, introduced a trial accreditation called ‘Positive energy and carbon reduced buildings (E+C-)’. ‘A statement of the commitment of public authorities and construction stakeholders to develop and bring into operation a new standard for new buildings by 2020. » In other words, the next environmental regulations scheduled for 2020. To support this trial, at the same time Ademe launched the Obec ‘Objectifs Bâtiments Energie Carbone’ programme.
Raising awareness and informing
With a budget of 3 million Euro in 2017, the aforementioned programme had three aims: to raise awareness and inform key players in the sector about the E+/C- standard, to provide the E+/C- monitoring centre with energy, environmental and economic data and to assist these same key players in taking ownership of the Life Cycle Assessment (LCA) method. For Romain Bonnet, a sustainable performance engineer at Bouygues Construction, the latter is probably the most important point. ‘On this point, there is a huge amount of work to be done with adopting the LCA method in the construction sector. Even if manufacturers started doing this several years ago, this is not the case for the entire value chain from the design to the final use of a building. The fact that LCA is becoming a requirement is a strong signal that things are, in my view, going in the right direction.’ In terms of the approach used, regions were contacted and, with the help of engineering company service providers, several projects were selected and evaluated.
Positive lessons on energy
What is interesting is that Ademe chose, with no sense of elitism, standard buildings to meet the criteria of the RT2012 regulations. And the outcome? The vast majority of projects attained levels E2 and E3. As a result, with regards to energy (E), the results meet expectations. All that remains is to go one step further and reach the objective of a positive energy building in 2020. ‘Levels E2 and E3 are anticipated to be those in the future regulations. A truly positive energy building which attains level E4 is still unusual’, points out Romain Bonnet.
Uncertainties over carbon
As regards carbon, the results of the Obec trial show that many uncertainties still remain. The majority of projects (all regions included) had difficulty attaining level C1. Of the 35 buildings tested in the Ile-de-France, only 6 managed to reach this target. The same was found to be the case in Occitanie, where only 4 of the 20 projects assessed attained a level C1. Several explanations were put forward. The first concerns environmental data related to materials and technical equipment. Romain Bonnet explains it as follows. ‘Despite a significant number of FDES (environmental and health declarations) on the Inies* database, there were just simply not enough to carry out a complete LCA study. The second reason is that in order to compensate for this lack of declarations, default data was made available and was heavily used by participants in the trial. However, this data is much inflated in order not to penalise manufacturers who have made the effort to make environmental data available. We are talking about a factor of 2 or even 3 compared to data such as FDES or PEP (environmental product profiles)’. The result was that on the sample of buildings studied in the Ile-de-France, the amount of data entered by default was 64%, which of course strongly penalises projects and therefore the overall assessment.
Streamlining and increased efficiency
Manufacturers and their representatives must therefore make a significant effort to produce FDES and PEP. This will result in a situation which better reflects reality. For Ademe, manufacturers of materials will play a major role in making insights more ‘efficient’. ‘And’, adds Romain Bonnet, ‘another difficulty has arisen in the different regions – namely the excessive reliance on interpretation and subjectivity in carrying out a LCA of a building. Which group should this product be assigned to? To what level of detail should we go? Results can differ widely if several people are asked to carry out the same review. This demonstrates a lack of sophistication in the method. As a result, it all needs to be streamlined and a much simpler method put in place with clear and common rules for all .’
These results would still need to be analysed in depth and, of course, take into account the conclusions of experts at Ademe, ‘All feedback on experience gained during the Obec programme will provide food for thought when designing future regulations’. It should be remembered, however, that regulations are expected at the end of the 2020, with possible application as from 2021. We are going to have to move fast because that is in the very near future.
To find out more
* Reference database for environmental and health data for buildings