Matxalen Etxebarria-Mallea’s research while affiliated with University of the Basque Country and other places

A country or a city is largely characterized by its architecture and urbanism. A robust understanding of the characteristics of the existing building stock provides a more solid basis for the development of European or national policies. In this chapter, we propose indicators to measure the general characteristics of the buildings at the national and regional levels, using as case studies Spain and two of its regions, Aragon and the Basque Country. Given there is no official definition of what the general characteristics of a building are, in this chapter we propose the general characteristics of a building whose knowledge can allow to lay the foundations for its improvement. We also studied the sources of information available in Spain and in the two mentioned regions for the development of these indicators and developed them when there were available data. Out of the fourteen proposed indicators, five could be fully developed, eight were partially developed, and one could not be developed due to lack of data.

Europe is setting ambitious targets for decarbonization by the year 2050. These goals are essential for mitigating the impact of climate change and transitioning towards a more sustainable future. Setting realistic and binding targets is a key component of this strategy, so the evidence-based approach ensures that these goals are rooted in a solid foundation of expected energy savings. Moreover, the energy renovation of buildings entails a series of benefits that go beyond energy savings, such as improvement in people's health and, consequently, economic expenditure in health systems reduction. In this chapter, we propose indicators regarding evidence-based estimate of expected energy savings and of reduction of costs for health systems from buildings renovation. We also studied the sources of information available in Spain for the development of these indicators, at national and regional scales, and developed them when there were data for the case of the whole country and two regions, Aragon and the Basque Country. Based on our study, it can be inferred that in Spain, although the current data sources provide trustworthy information regarding expected energy savings, they fall short in providing sufficient details to set targets concerning the reduction in health costs attributed to energy efficiency measures and improved air quality. At the regional level, there is room for improvement in both aspects.

Evidence shows that people have a major impact on building performance. Occupants’ impact is especially important in social housing, where their occupants may present greater vulnerabilities, and their needs are not always considered. This study aims to analyse the socio-demographic influence in social rental housing concerning hygrothermal comfort and energy consumption in a case study located in Vitoria, Spain during the first 4-month period of 2020 and 2021 (during and after COVID-19 lockdown). An innovative data management system is included, where the users and administration can see in real-time the temperature and consumption in the dwellings. A 2-phase method has been applied; phase 1 is associated with outdoor climate conditions, building properties and social profile. Phase 2 determined the results in energy consumption, indoor hygrothermal comfort and occupant energy-use pattern. The results show that the comfort levels and energy consumption vary according to the analysed social profiles, as well as the heating activation periods and domestic hot water system usage. In conclusion, socio-demographic characteristics of social housing households influence the hygrothermal comfort of their dwellings, occupants’ behaviour and heating and domestic hot water energy consumption.

The reduction of energy consumption in the built environment by energy renovation strategies is an important target to deal with buildings sector's negative impact on our planet. Regardless of the potential for energy and emissions savings, building renovation has other relevant effects on users' quality of life and health that has not been so well assessed. The present study aims to contribute to current building energy efficiency targets, particularly to Spanish residential building sector, from a still non-existing integrated vision. To this end, an evaluation method was developed to discuss the impact of energy renovation interventions on annual energy demand, indoor thermal comfort and indoor thermal health risk variation. The approach was applied to an open linear residential block located in the Basque Country (northern Spain), and twelve scenarios based on three variables were analysed using DesignBuilder tool. The results obtained show a clear contrast in the impacts caused by energy refurbishment interventions. In particular, the generalized decrease in the number of hours in which indoor temperatures are within comfortable ranges is significant in contrast to the noteworthy reduction in annual energy demand. In conclusion, the results suggest new factors to be considered when updating energy renovation policies.