Sustainable housing that both creates good indoor environmental quality (IEQ) and avoids unnecessary energy use has proved difficult to realize. Renovations of multifamily houses provide an opportunity to find this balance. This study concerns whether tenants perceive that conditions for achieving sufficient IEQ with low energy use exist. Focus group interviews with 42 participants, in areas where the rents were in the lower range and included heating up to 21 degrees C, aimed to capture the tenants' perceptions of: IEQ and actions taken to regulate it; information and control; the connections between IEQ and energy use; and the role of the housing company. Good IEQ was crucial to interviewees, who described it as sufficient heat without draughts, ability to ventilate, and no disturbing sounds or smells. The main responsibility was attributed to the housing company, but daily regulation controlled by tenants. However, unclear interfaces between tenants and the systems that regulate IEQ make it difficult for tenants to act as a positive part of the system. Tenants did not link IEQ to energy use. A holistic view of the physical environment's affordances, including intuitive interfaces, could optimize the balance between good IEQ and energy use.

Energy efficiency measures in residential buildings typically include changes in ventilation and heating systems, and increased thermal insulation of the building envelope. The expected energy efficiency is not always reached, despite large knowledge and professional implementation of each separate measure. There is a lack in understanding of how technical systems interact, and how the occupants are influenced by and in turn influence the systems by their behaviour. A holistic view and a transdisciplinary research approach are needed to understand relevant interactions and propose integrated energy efficiency measures. The aim of this paper is to reveal challenges in transdisciplinary research projects that include real world studies on both humans and technical systems with measurements before and after renovation of multifamily housing. It is based on experiences from the PEIRE-project (People, Environment, Indoor, Renovation, Energy) carried out by a research team with expertise on environmental psychology, human behaviour, interaction design, universal design, building physics, building services, thermal comfort, aerosol technology, exposure assessment, acoustics, daylight, and complex thinking. Differences in theoretical bases and methodology needed to be dealt with. Metatheory building could help with the transition from a multi- to a transdisciplinary understanding.

Indoor environments have a large impact on health and well-being, so it is important to understand what makes them healthy and sustainable. There is substantial knowledge on individual factors and their effects, though understanding how factors interact and what role occupants play in these interactions (both causative and receptive) is lacking. We aimed to: (i) explore interactions between factors and potential risks if these are not considered from holistic perspective; and (ii) identify components needed to advance research on indoor environments. The paper is based on collaboration between researchers from disciplines covering technical, behavioural, and medical perspectives. Outcomes were identified through literature reviews, discussions and workshops with invited experts and representatives from various stakeholder groups. Four themes emerged and were discussed with an emphasis on occupant health: (a) the bio-psycho-social aspects of health; (b) interaction between occupants, buildings and indoor environment; (c) climate change and its impact on indoor environment quality, thermal comfort and health; and (d) energy efficiency measures and indoor environment. To advance the relevant research, the indoor environment must be considered a dynamic and complex system with multiple interactions. This calls for a transdisciplinary and holistic approach and effective collaboration with various stakeholders.

Activities of moulds from domestic dwellings are normally classified into three groupsprimary, secondary, and tertiary colonizersaccording to the minimum relative humidity they require to colonize a substrate. With the help of isothermal calorimetry it is possible to directly measure the thermal activity from moulds as a function of climatic parameters. This makes it possible to provide more precise and detailed information of the growth behavior of these types of moulds under different temperature and relative humidity level than traditional methods. From this study, it is found that the optimal relative humidities and the recovery from drying are different for these three different colonizers. The fungal activities during desorption process are higher than during adsorption processes under the same relative humidity level for all of the samples. Such information makes it possible to model mould behavior indoors and can be used to access the risk for mould growth in the buildings.

Isothermal titration calorimetry (ITC) is the measurement of the heat produced by the stepwise addition of one substance to another. It is a common experimental technique, for example, in pharmaceutical science, to measure equilibrium constants and reaction enthalpies. We describe a stirring device and an injection pump that can be used with a previously described isothermal calorimeter to perform ITC measurements. Two experiments are also described: an acid−base titration and the binding of Ba2+ to the macrocyclic compound 18-crown-6. These experiments visualize the difference between strong and weak interactions (large and small equilibrium constants) and introduce how reaction enthalpies and equilibrium constants can be calculated from titration calorimetric experiments.