The scope of opportunities for researchers to change their lines of research is crucial for the performance of science systems. These changes themselves vary in terms of their impact on the field - from local changes to field-level changes (scientific innovations) and from low-cost to high-cost changes. Opportunities for changes strongly depend on formal organisations because they control many conditions of research. When researchers want to start new lines of research two types of formal organizations are particularly important in allocating resources and reputation: the research organization and external funding agencies. Both organisations co-shape the protected space a researcher has in this situation. Using data from three empirical projects, I explore the use of the concepts ‘protected space’ and ‘ease of access to resources’ as tools for comparatively analysing opportunities for changes of lines of research undertaken by researchers at Dutch universities in three disciplines. The results show that the scope of sufficient protected space is small, i.e. that conditions for changing lines of research were often insufficient. The overall conclusion is that the Dutch research system tends to delay the start of new lines of research for most researchers but a few members of the elite. The lack of protected space can be traced back to the influences of both types of formal organisations.