The thesis details the graduation project about saving energy in care homes through behaviour change. The project is part of a bigger project between TU Delft and Eneco, a Dutch energy company. Working towards their vision to provide their customers with services that help them save energy, Eneco invested in corporate customers to review and renovate their buildings to become more sustainable and energy efficient. Users of a building often have a measurable influence on the energy consumption of a building. In order to meet the desired energy performance, the occupants will need to change their energy use behaviour. Eneco is interested in helping their customers save more energy by supporting such a behaviour change amongst occupants. Excessive energy consumption is a problem for the Dutch healthcare sector, as they need to draw away money from their own care budget to cover their energy costs. This results in less care per client due to the lowered budget. Amstelring, a care organisation and one of Eneco’s corporate customers, recognises this budgeting problem. Amstelring’s care homes formed a case study for this project to find out how energy can be saved in care homes through behaviour change. In health care institutions like care homes, the main driver is providing good care to clients. As such, the wellbeing of clients is of great importance. Their wellbeing is influenced by the indoor climate, mainly temperature and fresh air. The indoor climate of a building plays a big role in its energy consumption, especially since the heat loss of a building depends on the difference between outdoor and indoor temperature. Meaning that the clients’ comfort needs are a crucial factor for how far energy saving practices can go; a tension exists between energy saving on the one hand and ensuring comfort on the other hand. Contextual research found that caregivers are a promising target group to design for, as caregivers have the ability to regulate comfort in all client rooms and are closely related to the clients’ needs. Currently, the only ways to maintain the comfort in client rooms is by manual actions such as turning on the heater or opening a window. This leads to fluctuations in the temperature, resulting in energy loss. When, in the future, the temperature is maintained along with the client’s preference, no extra energy will be lost. Clients are often (partly) incapable of performing the actions for maintaining comfort. Therefore, communication with caregivers is crucial to maintain the comfort effectively. However, there is a communication gap between caregiver and client that makes it difficult to maintain the client’s comfort effectively; caregivers feel a lot of time pressure which makes them more focused on providing the primary care for more obvious client needs; clients, in turn, sometimes find it difficult to express how they feel and are sometimes hesitant to call a caregiver for help when they feel uncomfortable. The final design, Fruitful, tackles the communication gap by bringing caregiver and client closer together to establish two-sided communication about comfort. Fruitful is a small table plant that reacts to its environmental climate by measuring the temperature, humidity and carbon dioxide of the surrounding environment. By reacting to these parameters, Fruitful offers a quick way to check whether something is wrong, without obstructing the caregiver’s workflow. The design is a metaphor to a real plant, which both caregiver and client understand. That way, the design facilitates caregivers and clients in a fun way to talk about comfort and to discuss solutions when needed. Even if the client does not express his discomfort, Fruitful’s indication provides enough motivation for the caregiver to ask. The indications from Fruitful leave room for discussion between caregivers and client and provide the opportunity to set preferences. As such, Fruitful is rather a reflection tool that helps caregivers and clients discuss heating and ventilation regularly. As a result, the comfort is maintained well and gas is used effectively. Fruitful is just the beginning of a future vision. A smart thermostat for each individual client room is the ideal future scenario, where caregivers are supported to maintain comfort efficiently and in a carefree way. Fruitful’s current design makes sure that caregivers and clients learn to communicate about comfort on a routine basis, which improves the effectivity of future solutions.