Number 19 Hofplein, built in 1960 to a design by C.A. Abspoel, is a typical example of modernism during the post-war reconstruction period when, because of the severe shortage of building materials, developers of non-residential buildings were obliged to use materials that could not be used for housing. This is the story behind the glazed curtain wall that was such a defining feature of the original design. The glass elevation is almost literally a curtain, stretched between two solid stone corner piers and characterized by a pronounced vertical delineation. In its original concept the building was also infused with the spirit of Rotterdam – open space – which in this case continues below the building, so that the first floor is in fact a raised ground floor. This modern monumental concept lent 19 Hofplein a certain grandeur, appropriate to the Shell office, which was negated by the 1990s renovation. In our submission for this invited competition we cherished the original qualities and translated them into a contemporary use and character.
The Shell petrol station is a later addition and has its own roof below the raised ground floor. Over time, this anomaly became an important identifying feature of the building. In the design these two key elements – the raised ground floor and the roof of the petrol station – are merged into a new, visually defining platform. This is the building’s lobby, which can be accessed from Hofplein via an expansive welcoming gesture in the shape of escalators.
Conservation and revitalization
The stone corners of the building are composed of hexagonal travertine panels. This distinctive pattern, representative of the building period, is used spectacularly in the new end elevation facing Hofplein. Large windows open up the winter gardens behind the glass facade.
The use of high-transparency, heat-reflective glass makes it possible to restore the original glass curtain wall in all its glory, offering a marvellous view of the building’s impressive concrete structure. At the point where the platform projects so distinctively, the glass curtain acquires a deep fold. Inside this fold is a helical staircase connecting all the floors of the building with the balcony above the petrol station. The deep fold is echoed by a series of shallower folds, a glazed reference to the original vertical emphasis.
Facade as energy collector
In collaboration with Deerns, the glass curtain was designed as an energy generating element. The folds in the curtain act like flues, naturally removing heat and supplying fresh air. Solar collectors placed between the columns and the glass convert solar warmth into floor heating in winter. In summer this system provides cooling via a heat exchanger.
commission: invited competition | client: PPF | project management: NL Asset Management | building services consultant: Deerns | program: office | floor area: 16.000 m² | design: 2016