MCA Post Occupancy Evaluation
26 Jul 2023
Currently, the construction sector contributes about 40% of the world’s greenhouse gas emissions, accounts for 36% of all energy consumption, and it is responsible for 50% of raw material extraction and consumes one-third of drinking water. Furthermore, particularly in the US and Europe, people spend almost 90% of their time indoors and there is evidence of how much this affects the health, well-being and productivity of occupants.
As a firm, one of the most important actions we have implemented, in terms of sustainability to counter our environmental impact, is the Post-Occupancy Evaluation (POE) of our offices, starting with the Bologna one. This strategy is important to understand the environmental gains of our activities and choices and it serves to develop strategies to improve our corporate behaviour. It will be strongly efficient also to apply to our projects, to understand the impact and the effectiveness of our design and environmental strategies.
In this regard, the POE of an existing building can represent an opportunity in its life cycle, as it allows us to measure the building’s performance and understand how the spaces affect the well-being of its users, highlighting possible margins for improvement in terms of consumption, and providing possible indications on strategies to pursue them. However, this methodology is still not very widespread, both nationally and internationally, except in the Anglo-Saxon context. Moreover, not all certification systems provide for third-party measurement and verification after the work is finished.
Modern POE methods have their origins in America, around the 1960s. The assessment focuses on the requirements of building occupants and includes topics such as health, safety, functionality, energy efficiency, psychological comfort and aesthetic quality.
More recently, the research group of the RIBA (Royal Institute of British Architects) defined POE as “a systematic study of buildings in use, which aims to provide architects with information on appropriateness to design, and owners and users with guidelines for optimising building performance”.
The purpose of the post-occupancy evaluation is to asset the environmental behaviour of a building and to collect information that can be used to improve building performance for the benefit of all stakeholders involved, with a view to continuous improvement. Among the information collected are: user response, energy consumption, indoor environmental quality, the actual performance of specific design strategies, etc.
The application of this tool to the MCA offices allows to:
- obtain useful information to improve the performance and comfort of their offices and employees;
- use an internal case study to acquire skills that can be applied to projects carried out for external clients, to assess the actual behaviour of buildings and provide input for improvements in subsequent experiences;
- contribute to the adoption of a corporate environmental management system, following the ISO 14001 certification, which would bring advantages in terms of optimisation of internal processes.
 United Nations Environment Programme (2020). 2020 Global Status Report for Buildings and Construction: Towards a Zero‑emission, Efficient and Resilient Buildings and Construction Sector
 Klepeis, N., Nelson, W., Ott, W. et al. (2001). The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants
 RIBA (2020), Post Occupancy Evaluation. An essential tool to improve the built environment
The most common POE methods can be divided into two categories: subjective methods and objective measurements.
- Surveys: on occupant satisfaction, thermal comfort, visual comfort and other customised surveys.
- Interviews: structured or semi-structured interviews, meetings and workshops with occupants and experts.
- Inspections by experts to identify problems through photographic documentation.
- Measurements of indoor environmental quality (IEQ): thermal conditions, lighting, air quantity and acoustics.
- Measurements of energy consumption: energy consumed is assessed through audits, sensors or utility bills.
- Measurements of water demand: evaluated via utility bills.
Generally speaking, subjective methods are used the most because they are the cheapest and help to identify problems easily. In particular, surveys are the most widely used method because they make it possible to quantify subjective data through questionnaires and compare the results. The fact that user feedback has become the main focus of POEs reflects how the success of a building is primarily determined by the level of satisfaction of those who occupy and use the space.
Within the MCA environment, it is proposed: the dissemination of a questionnaire among users, the analysis of energy consumption, the direct observation of the building and proposed strategies of implementation.
These simple activities make it possible to understand the occupants’ level of satisfaction with the building, how they evaluate it in its different parts and according to different criteria, and which elements most influence comfort, consumption, and environmental impact.
The questionnaire is divided into questions relating to the type of user and their use of the workspace, thermal, visual and acoustic comfort, travel and eating habits during office hours. Once the answers have been collected and statistics have been drawn up, the qualitative and a posteriori analysis of the spaces, by studying the descriptive drawings of the building and direct observation of the rooms, allows initial considerations to be drawn concerning possible causes, to optimise the quantitative analyses to be carried out later.
The information gathered through qualitative analysis provides support for the quantitative phase. This involves:
- the performance of on-site measurements;
- the elaboration of environmental simulations;
- the analysis of consumption accounted for and estimated.
During summer period, the measurements were carried out through: data loggers that are installed at significant points in the building (defined based on the findings of the qualitative analysis carried out previously) and that allows a profile of temperature and humidity to be traced for a typical week, including weekends; specific instrumentation that allow the illuminance on the working surfaces and the surface temperature to be measured at specific times of the day and under different conditions. Simulations will be done in winter too.
The consumption analysis is carried out by collecting consumption information (bills), analysing the charging cycles of some significant supplies (e.g. paper, water, etc.), in agreement with the Office Manager, and identifying a standard period.
Thanks to the constant monitoring of the situation and the various parameters considered, it was possible to outline the environmental behaviour of the office. On one hand, these results help to understand “where we are” concerning the various environmental standards and benchmarks and on the other hand they help to draw up a series of implementation strategies to be carried out both at the company level and also in everyday life by all users.
The results showed that it is possible to control and minimise the use of air conditioning systems and favour passive strategies that allow a considerable reduction in consumption. It is also important to the topic of daylighting, for which the orientation of the building, the position of the skylights and the presence and possibility of using and modifying the shading systems, allow users to experience the best possible working experience with the possibility of being able to considerably reduce lighting costs.
All the considerations and data collected during the post-occupancy assessment analysis of the offices made it possible to draw up implementation strategies to bring the working experience to a higher level of comfort and significantly reduce consumption and the resulting impact on the environment. Targets for improvement are therefore identified, according to increasing levels, in terms of reducing consumption and improving comfort, and possible alternatives are proposed to pursue these performance gains, to be conveyed not only through a corporate strategy but also through user empowerment and involvement.