Despite the increasing virtualization of work and associated new working methods, many people still use the office as their main place to do work. The office is also a place where the worker spends a lot of time. But what are the actual the working conditions for office workers? And how do employees experience the comfort of office buildings in which they work? Surprisingly little is known about real and perceived comfort of offices and the interaction between these two aspects. The current research study, Comfort in Professional Offices, a collaboration between the Hanze University of Applied Science Groningen and The Hague University of Applied Science, aims to create a comfort index which measures the gap between the office and the employees perceived comfort of that office.