Federica Naspi

Importance of Energy Prevision Accuracy for Zero-Energy Buildings

The energy-related attitude of occupants can cause big variations between real and predicted building energy consumptions. Such discrepancies have been found especially high in nZEBs and energy-efficient buildings. Considering that actual regulations impose the nZEB target and that in such optimised contexts users’ actions have a considerable impact, a comprehensive knowledge of occupants’ behaviours should be the main goal of the building sector to effectively reach the expected performance. In this perspective, this chapter firstly analyses the human-building interactions in nZEBs, by focusing on the energy implications of their attitudes. Then, nZEBs’ performances are investigated and reasons for the operation gaps are highlighted. Finally, literature results from energy simulations are reviewed to evaluate the influence of different users’ energy attitudes.

Experimental Data Acquisition

The acquisition of people’s behaviours in buildings is extremely important for the evaluation and the improvement of the building performances, as well as for the development of behavioural predictive models. Both occupancy patterns and users’ interactions with devices influence the building energy use. Therefore, researchers adopted many techniques to record these data, customising the monitoring system according to the building features and the research aim. This Chapter offers an overview of the techniques adopted in experimental campaigns to detect occupancy patterns and acquire behavioural and environmental data.

Occupants’ Behaviours Impact on Indoor Environment

People modify the environment by both their adaptive actions and their own presence. Perturbations due to human activities can be studied using decomposition methods since the environmental variables trends can be interpreted as temporal series. This approach has been applied to several parameters, recorded during an experimental survey, and the results are presented in this chapter. Statistical analyses have also been adopted to investigate users’ influence according to different building uses.

Triggers for Users’ Behaviours

People behaviours have an undeniable influence both on building performance and on indoor environmental quality. To predict their actions and obtain accurate predictions, it is of primary importance the understanding of their decision-making process. This chapter offers an overview of the main factors that stimulate users’ behaviours. It firstly proposes an analysis regarding objective aspects (i.e., environmental variables, time-related events and contextual factors), aiming at underlying the triggers for each adaptive action. Then, it focuses on subjective aspects (i.e., physiological, psychological and social factors), in particular, highlighting how people’s attitudes change in the nZEB contexts.

Occupants’ Adaptive Actions

People adapt the indoor environment to restore their preferred comfort sensations intervening on building’s controls. Such adjustments have a great impact on the building performances, especially in the nZEB contexts. As a consequence, the investigation and understanding of human-building interaction patterns can help to bridge the gap between real and predicted energy consumptions and to design buildings tailored for users’ preferences and needs. In this perspective, the current chapter investigates many adaptive actions, highlighting, in particular, the most recurring and frequent behaviours the occupants perform in buildings.

Conclusions and Future Challenges

Occupants’ behaviour in buildings has been recently recognised as one of the main aspects influencing the overall energy consumptions. The users’ decision-making process is a complex mechanism, affected by surrounding’s conditions, personal features and random events. However, people behaviour is usually underestimated since, in the simulation environment, it is reproduced according to pre-determined and fixed rules. This static and oversimplified approach led to incorrect evaluations, energy wastes and big discrepancies between real and predicted building performance. Such considerations are even more relevant for the nZEBs. Due to the recent regulations on the energy reduction, the nZEBs’ diffusion is (and will be) the main target of the building sector. As a consequence, reliable evaluations are essential to reach the nZEB target. In this view, this book aims at offering a complete overview of the human perspective, especially in nZEBs. In particular, this final Chapter aims at providing recommendations and suggestions for a correct inclusion of the behavioural components in the building process and it also reports some open problems and future directions. The considerations regard many different (but strictly connected) aspects: the triggers of users’ behaviour, the effects of users’ actions both in environmental and energy terms, the methods to acquire behavioural data and the development of behavioural models.

Modelling, Implementation and Validation Approaches

Behavioural models are fundamental tools to predict users’ behaviours and evaluate buildings’ performance both during the design and operation phases. Occupancy patterns and human-building interaction have been forecasted according to several approaches, which lead to different levels of accuracy and reliability. Such models improve their usefulness when implemented in Building Energy Performance Simulation (BEPS) that, coupling specific behavioural tools with environmental simulations, can enhance the results and bridge the performance gap.