The Loevestein fortress consists of a medieval castle more than six centuries old and a number of buildings from the 17th century. Much has been built and rebuilt over the centuries. In 2013 the outbuildings of Slot Loevestein, the most famous castle in the Netherlands, were renovated. As most of the outbuildings have monument status, this requires creativity, expertise and experience in working on monuments. Sustainable, energy-efficient solutions are applied. For example, several outbuildings are equipped with Clina radiant heating systems installed in the walls and floors.