Furnishing penthouse with sleek interior. That is the best description of this penthouse on the IJ. The penthouse was delivered casually by the contractor and completely remodeled by Van der Windt. The layout of the penthouse has also changed. The design of the interior is by Piet Boon and, for Van der Windt, counts as one of the sleekest and most modern projects the experienced construction specialist – the perfect party for furnishing penthouse with sleek interior – has worked on. The complete interior was carried out by Van der Windt in consultation with the interior designer.