Project Name: Penthouse West399

Location: The Netherlands

Date Completed: 2019

Interior Designer: Powerhouse Company

West399 started life as a high-quality Modernist building, it was then altered throughout the 80’s and 90’s. The renovation began with stripping away these additions to reveal the original beauty of the interior, complete with lofty high ceilings, round columns and mahogany-framed strip windows. The exceptionally rich palette of materials was restored to its former glory: warm brick wood outside, with slate, travertine and solid hardwood inside.

Rich materials and high-quality detailing similarly define the glass-box penthouse structure on the roof. A new addition that develops the European Modernist idiom of the building with a thoughtful contemporary interpretation of its transatlantic incarnation. Originally planned as a two-floor construction, De Ru and Vos changed the design when one of the apartments below failed to sell. The 450m2 penthouse apartment now comprises a one-layer new-build perching on the roof and surrounded by a roof garden, and a portion of the existing building below that roots it in the original structure.

The two floors are linked by a generous, champagne-coloured spiral staircase, via which visitors arrive in the living room, surrounded by glass and by jaw-dropping views of the River Maas and the city skyline. The penthouse façade is the largest load-bearing glass façade in North-West Europe. The roof rests on top of it, anchored by steel cables concealed in the joints between the glass sections. The glass is set at a slanting, rather than straight, angle for added strength. Outside the glass rectangle, a generous overhang provides shade and repeats the form of the patio below. Grey was chosen for these surfaces to avoid glare.

Once upstairs the load bearing glass facade provides you a with a beautiful 180 degrees view from downtown Rotterdam in the East towards the harbour in the West.

The house provides spaces for the family to be together and to be more private. The transitions are very fluent and natural. The use of materials gives expression to the use of the spaces and respects the architecture of the existing brutalist office building.