Architecture, Building and Structure Design Villa K Residential Project by Ruud van der Koelen Villa K is a contemporary private residence on the sloping south flank of the Holterberg in Holten, the Netherlands. The house is spacious, with a building volume of 6,500 cubic meters and a gross floor area of 1,850 square meters. A glass mosaic facade, refined detailing and sliding doors with five meter triple glazed sashes shape the exterior. Villa K is a self-sufficient smart home that requires little maintenance. The design integrates the building into the surrounding landscape as one coherent whole.