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CUBE 2020 interview: Competition for energy savings in commercial buildings

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Quai Vendeuvre

Quai Vendeuvre of Poste Immo, the 2nd edition's winner

38,5% of energy savings in CUBE 2020? It's possible.


The building Quai Vendeuvre won the grand prize of the energy savings contest CUBE 2020 in 2016. While the 3rd edition of the contest just started, let’s ask the IFPEB’s director Cedric Borel about the score of the second edition’s winner, who made 38,5% of energy savings within a year!  You said 38,5%, really? How is that possible?


Marguerite Dornier: You said 38,5%, right? It’s huge, isn’t it?


Cédric BOREL: Yes! But still far from the 42% made by the Crédit Agricole of La Loire in 2008 in the Energy Trophy contest! This contest used an evaluation method similar to ours:  the three previous years’ consumptions are used to make a baseline and the performance is evaluated during a full year. I remember that the Crédit Agricole operated a reuse of the dissipated heat by big computing servers, then the resulting decrease of heating and cooling needs was a significant gain. In the American contest*, an elementary school saved 52% in 2013, another saved 45,2% in 2013… Our champion is still below.


 *Battle of the Buildings


MD: How can you be sure of those figures?


CB: The top five of the general ranking of CUBE 2020 have been thoroughly audited onsite by an independent third party, a voluntary IFPEB member who went and certified the performances. A full review of the given data, the means and the level of engagement has been notably made in the Quai Vendeuvre building by a MRICS accredited sustainable development manager. As for the calculation, you wedge the estimate consumption by using an energy signature of the base years, in accordance with the IPMVP method, to adapt the values to climate conditions and possible use variations. Then, you compare the values to actual bills, more reliable. This is a classic for thermal engineers, but we boosted the method so it is more accurate and consistent, thanks to our partners’ expertise.


MD: Then you immediately wonder: how did they do? Were they that bad before the contest?


CB: Yes, there was a potential, but the question remains: “how to mobilize quickly within a year?”. It was due to the park’s inspector’s ingenuity and experience: he sold more comfort to his users, in exchange for a full collaboration. The atmosphere was good with the tenants, a very appreciated technical referrer onsite played the game and they found some improvements to make: a main source of economies was the lowering of setback temperatures, which were initially programmed at 24°C in a rather ancient building.

I hear the comments on how it is to improve and win when there is a large potential. But it should be remembered that CUBE makes its rankings in accordance with the percentage of energy savings. Therefore, they are relative. If you consume 100 KWhEF/m²/year, 10% is 10 kWh… If you consume three times more, you have to save three times more. The relative method creates a level playing field. The good question is: “have you already exploited the full potential or not?”


MD: So, the users “played”?


CB: Yes, the collaboration on-site worked well. Some satisfaction surveys were made, sharing events were organised (breakfasts, brainstorming sessions) and the operator made a little trick explained below in his testimony. The negotiation was all about “comfort versus energy efficiency”. And it worked. Concretely, the desks were put away from the windows and the cold walls, they worked on office design, which allowed them to rise again the operative temperature in workstations and lower the air temperature. The “pirate” electric convectors were removed because the comfort had been recovered otherwise.

Post-it in the elevators would inform the users of the gains, the information was duplicated via email, and it worked very well.


MD: Technically, what else did they do?


CB: They also executed technical improvements, such as the installation of thermostatic valves on the heat transmitters just before the contest, the relamping (now partly LED-lighting), or the installation of occupancy sensors. Other minor anomalies were rectified (programing, unnecessary energy consumers, electric power stubs, etc.)


MD: If it’s users-dependant, how to maintain the momentum over time and avoid the “bouncing effect”?


CB: I hear our POSTE IMMO contacts say that the new employees who move in the building are “trained” to ecogestures by those who experienced the contest! We wish them of course to maintain their performance, and we will keep in touch with them following the contest: we’ve already made a year-and-a-half-long journey together…


Testimony of Joachim Touilin, park’s inspector, North-West RD in Poste Immo for the winner building Quai Vendeuvre, golden cube of the grand prize, CUBE 2020 2nd edition.


Our participation to the first edition of the contest made us enter the second edition with the lessons from a first “contest” experience. Indeed, a part of the results is linked to the good collaboration with the users. Debugging actions and several technical interventions were done in the new participating sites to get ready for the competition on July, 1st 2015. Site-visits made us note a few common-sense actions that could be immediately undertaken. The contest was embodied and the dialogue with users became possible thanks to a tandem work with an on-site relay close to the users, and regular visits of the park inspectors.

Encouraging them to speak and associating them to a CUBE 2020 synergy implemented in users’ minds the interdependence between comfort and effort: the whole building went along with it! In the Quai Vendeuvre building, we could see during the contest a “morning ritual”, which consisted in simultaneously opening the windows to ventilate.

Regarding the temperature set points’ drop, we optimized the temperatures and the comfort until finding the satisfaction of users. At first, we significantly reduced the heating and we waited for the reactions, which came before long: we offered to re-increase the heat by one or two degrees (far below the initial temperature) and everyone was happy with that!


“With offering the users to improve their comfort, we fully associated them to our energy savings approach.”


The contest’s results exceeded our expectations for the Quai Vendeuvre site and showed the efficiency of mobilizing the users; who were invited to a breakfast, to give their opinion and their good ideas through post-it, regularly informed of the results through smileys displayed in strategic places (stairwells, entry hall…), they contributed to creating a momentum for change of behaviour in the building, and also to leading optimizations in accordance with their needs.


Why would you recommend CUBE 2020?


The contest CUBE 2020 is an excellent initiative for the sustainable development. It allows to mobilize the users and offers a good media exposure. The CUBE 2020 is both entertaining and a wonderful tool for energy reduction.