Making buildings more efficient and comfortable for occupants

Published on 04/09/2020

Most of us have worked in stuffy, noisy, cold, hot, inefficient, or uncomfortable workplaces at one time or another. Sometimes it’s the building at fault, sometimes the behaviour of its occupants.

The European Directive on Building Performance, related to increasing the energy efficiency of EU building stock, was revised in 2018, promoting more renovation as well as smarter buildings. In this context, LIST recently launched a research project entitled Post Occupancy Evaluation SYstem or POESY for short, to tackle issues surrounding uncomfortable or inefficient buildings.

Principal Investigator from LIST’s Environmental Research and Innovation (ERIN) Department Annie Guerriero explained the idea behind the project. “Since higher building energy efficiency standards are required all over Europe, including Luxembourg which has defined very ambitious targets, we’ve had architects and engineers experimenting with new concepts and new materials to achieve better energy efficiency. The research idea is to investigate how this changes in the way buildings are constructed impacts the occupant’s comfort, as well as the new generation of buildings”.

In order to capitalise on each experience and review lessons learned, post-occupancy evaluation has been developed and used in order to collect data about building occupants and their satisfaction, for example perceived comfort, space utilisation and resource consumption.

“The idea is that by using a certain methodology we can define the performance criteria, to measure various conditions, then we are able to see how to improve the building, in the short term, medium term, and long term,” Annie explained. “Every building is a kind of prototype, but for Nearly Zero Energy Buildings (NZEB) it is even more the case! Architects and engineers have set objectives of performance during the design stage. Then we want to verify if the performance is actually reached when the building is occupied, and finally capitalise on these experiences and improve future buildings”.

The aim is to gather feedback from occupants, explaining what is comfortable or not comfortable for a building so that adjustments can be easily made. In a longer term, the plan is to transform buildings in their life cycle.

What do you change in a building?

“What we do is to collect data from the occupants - Post Occupancy Evaluation - so the building is occupied and we collect the feedback from them, on their perceived comfort, and then we take data from sensors placed in the building, and we connect data with a BIM (Building Information Model) from which we can centralise the data. It’s a model where we can see the representation of the building, and also retrieve information related to building elements, material, equipment, etc,” Annie stated.

The types of measurements taken include sound level, natural light, the view towards the outside, the indoor air quality as well as the equipment provided to occupants. “We have an online questionnaire sent to the occupants that’s able to evaluate and determine, for example, that sound comfort is at a certain level of satisfaction. From that we will be able to detect zones that are noisy. Then we can plan for example, moving a meeting room next the kitchen, to inhibit too many people passing by, or make the meeting room enclosed, or add acoustic panels, in a way to limit noise impact. In other words our tools supports the reconfiguration of the building layout,” clarified Annie.

POESY is still in its infancy and so far is able to gather feedback from occupants, and data from sensors to feed the BIM model and give a centralised overview of a building. “The step to come is to identify what the architects and engineers planned in their simulation before construction to achieve a certain set of parameter performance,” said Annie.

An example of this is that in the middle of summer a building may be calibrated to not exceed 26°C. But what if the indoor temperature rises higher? Is the building being used correctly by occupants? “In these conditions maybe there are windows that should be open to limit the heat when there’s a heatwave, or the windows should be open at night to reduce temperature and then closed completely in the afternoon,” Annie explained, “so with all the data we collect we will be able to see if it’s people who use the building incorrectly. We can then correct peoples’ behaviour helping them adapt to the building criteria. That’s a first perspective”.

For that to occur the performance gap needs to be measured and appropriate actions for improvement proposed. The changes need to be deployed followed by monitoring to see if the results indeed produce the predicted positive impacts.

But have tests already been carried on actual buildings or is it still just theory? Annie clarified. “We are right at the start, so just a prototype at the moment. We’ve tested a bit in the Maison d’Innovation (LIST's Belval building) and we were just about to expand the testing when Covid-19 hit, so a bit of bad luck”.

The industrial sector is also being studied and engineering offices are working on their own “comfort labels”. In this context, POESY has attracted the attention of Secolux, an engineering and control office. “They realised that their comfort label could be aligned with our technology, and they found this prospect very interesting”.

All data received by POESY can be accessed via a Facility Manager Interface presenting all the data and showing the comfort for occupants. It also displays sensor information connected to air quality sensors, etc. “From that an area can be selected in the building, then a room so we are able to see the values of that room,” outlined Annie, “and if a room is uncomfortable, we’ll be able to see why via this interface and think about how to improve it”.

Is it a 100% LIST project?

“It’s a prototype that is 100% LIST, developed by SIA (Service Innovation Accelerator Platform) within the ITIS team, and with me as a product owner. What we want to do is to place the tool in different areas. For the moment we are trying to define the difference between the theory and the tools, but also work out the scope of functionality, the way of treating the data and being able to give recommendations for improvement for the building,” said Annie before underlining that not everything has been put into place yet and discussions with Secolux are continuing. “So we are seeing how to create a collaboration with the company around this tool. They are interested in being a partner in a joint project”.

What’s the goal in the end? A commercial product?

“My ambition, as I’m a researcher, is more a dimension of research associated to the software, so not in the commercial aspect at first place. Of course my objective is to be able to deploy the research in a pilot project and see if it has a positive impact, because it is obvious one can’t create a software tool if at some point we are not prepared to face reality and the real world.” Annie then pointed out that currently this was more of a service, but suggested that it could maybe evolve. “It is a really young prototype. If you look at the start and estimate what we get to in the end, there may well be considerable difference”.

When asked at the end of the interview if the research had anything to do with feng shui methodology, Annie laughed. “Not at all although there could be some elements, but it is not my domain at all. What we do is all about processing data, it is not shall we say, a science that is ‘slightly obscure’, the idea is to collect the data and see if we can improve the comfort of people. The BIM model is taking shape and with all the data we will be ready to provide recommendations. However, one can see clear links towards developing working and living environments where well-being, health and safety are central design parameters”.

About Annie Guerriero

Dr Annie Guerriero is senior research engineer at LIST (Luxembourg) where she has worked since 2005. She is an architect graduated from the Victor Horta Institute (Brussels, 2001) and she achieved a master in “Modeling and simulation of built spaces” in 2002. She obtained her PhD in April 2009 in Architecture Science at the INPL (Institut National Polytechnique de Lorraine). Currently, she supervises research projects and contributes to the following topics: BIM, 4D model, Collective decision support for AEC, Smart building/city, Perceived comfort & Post-Occupancy Evaluation.