The architects provided a very strong initial architectural concept of the glass dome. The detailed design work, structural calculations and erection of the entire glass roof were then developed in close collaboration between seele and ColladoCollins. The age of the building and the limited knowledge about its load-carrying capacity called for an intelligent design that would not be susceptible to settlement and would carry the loads without transferring them to the glass roof. The aim of seele and the architects was to not only guarantee a pleasant internal atmosphere for the future office users but also provide an aesthetics that is reminiscent of the industrial character of this 100-year-old building. Accordingly, the constructivist structure of vertical and diagonal tubular sections is modelled on classic examples from the 19th century.
The glass roof is supported on a new steel I-beam structure erected on the level of the existing second floor. At its highest point, the roof joins up with the new central service core and pinned-end columns support it off the fourth floor. Vertical tapering tubular members dominate the appearance of the glass roof. Together with the diagonal, shallower tubes, the result is a distinctive lattice. Different member depths and a random arrangement of diamond-shaped glass and solid panels create an exciting surface which – viewed from any angle – are a remarkable organic glass envelope.
Another special feature of the seele design is the member/node arrangement. Six members intersect at every node. Each node is a milled solid element and in some cases more than 50cm across. The form of these nodes imitates the design of the members in such a way that they blend almost imperceptibly into the surface. In the highly aesthetic, homogeneous surface, the vertical sections simply converge. A consistent, productive climate on all three new floors is achieved by combining transparent insulating glass units made from laminated safety glass with a solar-control coating with opaque solid panels made from insulating glass units, thermal insulation and powder-coated sheet metal. The sealing system makes use of seele’s tried-and-tested “2nd line of defence” system. In contrast to standard solutions, in this system the elements are not just glued together but sealed mechanically as well as by applying pressure from outside.
One hundred years of building history separate the historic structure itself and the modern three floors beneath the glass dome. However, seele in collaboration with the design team have managed to unite both eras perfectly by creating a sensitive glass roof solution and at the same time creating a new landmark for Hammersmith.
Renderings: © ColladoCollins Architects, project image no.1 and 2: © McLaren