A high proportion of the CO2 emissions worldwide are caused by the construction sector or are associated with buildings. Every part of the industry needs to reduce its share of emissions, so the building sector must also do its part. One possible solution for achieving this reduction in the field of load-bearing structures is the use of adaptive structures. This research focuses on adaptive slab structures, which require specific actuators to be integrated into the system. Conventional actuators are not suitable due to the prevailing requirements, namely installation space and performance. For this investigation, the actuator is divided into different functional components. A rough description of the requirements for one component, namely the energy converter, is given. Different concepts are developed, tested, and compared with numerical results. Due to the requirements, the concepts are limited to hydraulics. The authors then present a comparison of different simulation strategies for the energy converter. Overall, this paper provides a new contribution to the design of energy converter concepts for integrated hydraulic actuators in slabs, along with experimental verification of the working principle of the energy converters to meet the requirements. A simplified numerical model is proposed to estimate the behavior of the energy converter during the early design phase.