Seismic isolation technology has the potential to significantly reduce the overall risk to nuclear power plants posed by earthquake ground motions. A testing programme is an integral part of a seismic isolation project. Not only do the isolating devices need to be characterized for design purposes, but the analytical procedures used in design need to be validating. Hybrid simulation is a testing technique which is a good candidate to experimentally assess the behaviour of an isolation system. The method combines the computation of the response of the isolated structure with the experimental determination of the behaviour of full-scale isolators under the demand imposed by the movement of ground and structure. This publication contributes to the assessment of the method as a tool for the design and safety demonstration of base-isolated nuclear facility buildings.