The objective of this study is to investigate the effect of indoor climate personal control actions on the temperature, CO2 concentration and other indoor environment quality (IEQ) conditions at the workstation of existing office buildings in the Netherlands under winter conditions. Indoor climate controls refer to, for example, thermostats, operable windows, etc. To map the effectiveness of the different kinds of controls, dynamic experiments were performed in offices. The experiments consisted of adjusting thermostatic valves on radiators/convectors, adjusting wall thermostats and opening windows. With advanced indoor climate logging measurement equipment response times and step responses were identified to conclude on how fast and how effective control actions are towards available indoor climate personal controls. The project outcomes give insight in what the control range is of distinct kinds of indoor climate controls. This knowledge can be used to improve the design of future office buildings, especially in cases where 'fast and adequate control' options are prescribed in output specifications.@en