Energy retrofitting of non-residential buildings with effects on the indoor environment: a study of university buildings at NTNU in Trondheim, Norway

The year 2050 is considered the deadline for achieving the European climate goal of net zero emissions, an essential sustainability milestone. Current strategies ask for higher retrofitting rates in the building sector, as most of today’s buildings will still be standing and be used in 2050, and longer. However, retrofitting strategies must consider energy and emissions reductions alongside social sustainability, targeting not only the building but also its users. Historically, the focus has been on indoor environmental quality, while other aspects of human well-being such as the quality of views were not addressed as frequently. Educational buildings can function as lighthouse projects, profiting from its many users as communicators. This article presents the retrofitting potential of the central building complex of the Gløshaugen campus of the NTNU in Trondheim in terms of energy, as basis to study the impact of retrofitting strategies on the indoor environment. The study consists of a selection of details, their building physical assessment, and a proposal of retrofitting measures. The results highlight the importance of human-centric definitions in the early (re-)design stages. Humancentric planning aspects can have diverse positive influences on the building’s users, especially in educational and other highly cognitive settings. Their impact however is strongly dependent on the selection of measures and their implementation. Interactions of the many aspects of well-being that can be addressed during retrofitting must be studied further as their interdependencies are often unclear and case specific. Human-centric retrofitting can function as a guide for upcoming mass retrofits throughout Europe for the sustainable achievement of climate goals.