Dutch painting, especially during the Renaissance, is renowned for its masterful rendering of the particular quality of the light in the Netherlands, a diffused light that reflects off the perfectly flat surface of the North Sea. It’s the light we see in paintings of domestic scenes, landscapes and still lives. It’s also the light that reflects off the famous pearl, the milk being poured, or in the love letter by the inimitable Johannes Vermeer. This same light is the dominant feature of the Voorlinden Museum opened to the public last September in Wassenaar, a stone’s throw away from the North Sea. Funded by the Dutch corporate executive and art collector, Joop van Caldenborgh, to house and make available to the public his extraordinary contemporary art collection, it was designed by Dirk Jan Postel, a partner of the historic Rotterdam practice Kraaijvanger Architects. The building is a perfect purpose-built machine, every aspect carefully thought through to allow the Dutch light - sharp and cold but at the same time all-enveloping - to flood the 20 rooms making up the exhibition space. Work on the concept was started in 2009, the practice working in close collaboration with the client, one of the world’s most acclaimed connoisseurs of contemporary art. They were joined in 2012 by Arup, brought in as consultant on the combined natural and artificial lighting system, and overall system design. The building itself has a deliberately simple plan: six parallel walls clad in sand colored stone - a reference to the sand dunes along the North Sea shore - partitioning the interiors, whose full-height glazed lights open out onto the old grounds surrounding the Museum, creating a continuum between interiors and exteriors. Hovering above the walls, a bit like a magic carpet, is a double layer roof. The upper metal covering reflects the southen light while the lower layer diffuses it throughout the building. The unconventional roof beam and pillar frame was especially developed together with Delft University. The sequence of paired columns - some embedded in the six walls that lend a regular rhythm to the longitudinal development of the building - is anchored to the foundations so that the colonnade of slender white uprights form an outer frame able to bear the full weight of the whole roof. This later comprises a top layer containing a mesh of 115,000 slanting metal tubes capturing and reflecting the natural light, and a secondary frame supporting a double under-layer of micro-perforated plastic and fabric that filters the light into the rooms below. It’s an ingenious system standing free of the masonry structure, the crystal glass infills, and most importantly, of the internal partitions, meaning that the interiors can be altered to cater for the works to be shown. During the day, the “solar collector” system channels light into the interior where - thanks also to the diffusive effect of the opalescent layer - changes in tone and saturation as the day proceeds or the weather changes are subtly perceived. At dusk, a system of smart LED lighting illuminates the tight mesh of metal tubes on the upper roof layer. The artificial light is reflected off the tubes and diffused by the opalescent panels to the museum below. Another innovative feature is the escape route signing. Concealed under a layer of plaster, signs become visible only in the event of an emergency and so do not distract attention from the works of art. The building under the huge roof also houses an auditorium, library, printing works, classroom, restoration laboratory, and museum shop. Joop van Caldenborgh’s challenge to the architects was to create a unique space for a unique collection. Seeing the pure Dutch light caress and bring to life works by Maurizio Cattelan or the huge sculptures by Richard Serra is proof of their achievement. Construction prowess and cutting-edge technology have been harnessed to produce a sleek yet simple 6,700 sq m exhibition machine designed by Dirk Jan Postel. Little wonder it won The Plan Award 2017 for the Culture section.