Transformation of the former head office of the Dutch tax authorities, also the oldest Jackblock building in the Netherlands, to residential building ‘De Generaal’ has been completed.
The office tower, centrally located in Rijswijk, has been transformed into a spacious, flexible, and sustainable residential building with both rental and owner-occupied apartments, designed by Mei architects and planners and upon the initiative of Aertgeerts Bouwgroep. By replacing the originally closed office façade with a new inventive glass façade with floor-to-ceiling windows and expressive balconies, the building now has a powerful appearance. The new residents – a diverse mix of young starters to seniors – enjoy exceptional comfort and an astonishing view from Rotterdam to the sea.
In 1966, De Generaal was the first building in the Netherlands to be built according to a highly innovative concrete construction, the so-called Jackblock system. A ‘Jackblock building’ is built in reverse. One starts with the roof floor, which is then pushed up by means of hydraulic jacks. Floor after floor is built in this way and jacked up until the structure is at height. After the transformation, some of the original details of the system (the Jack blocks) have been left in sight in the bicycle parking of De Generaal.
From closed office facade to maximum transparent glass skin
The arguments for the preservation and redevelopment of the existing office building were obvious. In addition to the cultural-historical value of the Jackblock building, the location, volume, spacious storey height, and the construction offered good starting points for a flexible and varied range of apartments.
The biggest challenges appeared in the skin of the existing building. After constructive research, it turned out that the circumference of the cellar was larger than the circumference of the tower. This led to the firm decision to completely remove the existing facade, extend the upper floors on all sides, and provide the building with a new all-glass skin. The new facade is constructed using the same type of frame profile for both the horizontal sliding windows at the balconies and the vertical sliding doors, bay windows, and fixed glass, resulting in a subtle tactility in the facade. At the same time, the expressiveness of the balconies contributes to a strong appearance, which refers to post-war architecture.
Unique residential product
The residential product in Rijswijk is characterized by a multitude of single-family terraced houses and gallery apartments. In the transformation of De Generaal, it was decided to offer an optimistic voice in contrast with the current housing supply in Rijswijk, ushering in a new era. De Generaal offers space for nearly 200 apartments with access to a porch, one-third of which are owner-occupied and two-thirds rental, with surfaces ranging from 70 to 100 m2. The floor-to-ceiling windows – at some places 5 meters wide without intermediate posts – offer the apartments a unique spatial quality and the residents a fascinating panorama of the region.
Part of the ground floor is intended for commercial facilities, creating an attractive and active plinth that improves the public space and connects to the environment. The individual storage rooms and a collective bicycle parking have been realized in the existing basement.
The transformation of De Generaal has resulted in a powerful, characterful, and maximally transparent residential building, which is an enrichment for Rijswijk both in terms of housing product and appearance.