Previous studies have shown that 'personalised environmental control systems' (PECS) improve occupants’ satisfaction with the indoor environment substantially. However, most of those studies were carried out under controlled conditions and long-term performance studies from real buildings are lacking. There is also a gap in the knowledge and tools necessary to make these systems widely-applicable in buildings. Based on this need, the objective of this project is to establish design criteria and operation guidelines for PECS and to quantify the benefits regarding health, comfort and energy performance. This includes also control concepts and guidelines for operating PECS in spaces with general ambient systems for heating, cooling, ventilation, and lighting. The scope of the project includes all types of PECS for local heating, cooling, ventilation, air cleaning, lighting, and acoustics. It includes desktop systems, which are mounted on desks, or integrated into furniture, chairs with heating / cooling and ventilation, and other types that can be found during the study. It also includes wearables, where heating, cooling, and ventilation are included in garments or devices attached to an occupant's body.