The largest castle in The Netherlands as it is known today is the product of the combined input of three people: a Baron wishing to recreate an ancestral home to impress, a Baroness with almost unlimited funds and an architect with a passion for gothic architecture and medieval craftsmanship. How does one approach the daunting task of restoring some 300 rooms? The sheer size of the late 19th century castle and diversity of materials and problems to be found inside make De Haar Castle a unique project in The Netherlands. The volume of work to be undertaken makes it impossible to use a focussed “micro” approach. It is imperative to treat each room and in extension the entire castle in a holistic fashion, to avoid fracturing the different parts of the conservation. The approach to the conservation carried out on De Haar Castle is multi (or cross)-disciplinary; a playing field where various crafts, material sciences, education, conservation and restoration meet and work together towards a common goal. This article is not the presentation of a finished conservation, however it allows a glimpse into the process of starting up a multidisciplinary project.