Design, engineering, prototyping, production and realisation of an innovative insulated facade system with integrated pre-stressed cable stabilisation with application for a polytechnical school INHolland with a laboratory for composite materials in Delft, NL. The process consisted of 4 major phases:

• The experimental (‘Sia Raak’ subsidy) design phase;

• The experimental design and engineering phase;

• The production and realization phase of the commercial facade system;

• The production and realization of the original composite facade system.

The initial conceptual ‘wild idea’ for the INHolland project by architect Rijk Rietveld, New York, was elaborated through different design brainstorms towards a radical innovative system for ultra-slim glass facades. In this facade system insulated glass panels of a depth of maximum 50 mm are integrated with internal pre-stressed structural composite cables, stabilising the facade against wind forces. Dead weight to be taken over by vertical deadweight rods in between the vertical silicone seams between the panels. The insulated glass panels are sealed by composite spacer frames. Many different solitary tests were done with the sealing and the carbon fibre components, with adhesion of silicone sealant on the carbon fibre frames and on the perforation of the carbon fibre used through the frames. In the actual engineering phase structural analysis was performed and tests on several levels were executed. The composite frames were substituted by conventional metal frames. The system is suited for facades of 14 m high. Under wind loading the facade system deflects as a sail membrane, with the deflections at the perimeter taken up by adequate detailing at the sides so that no breakage occurs and the membrane facade is regarded as fail safe system. A prototype of the corner was constructed and tested for practical approval. Due to the refusal by the glass panel manufacturer to supply a guarantee on inadequate number of tests with inadequate quality, the integrated system had to be changed into a duo-system with internal pre-stressed cables and integrated dead weight suspension rods. The project consisted of 2 large facades executed in this manner and one more narrow segment facade exactly in the experimental mode, for performance evaluation. The facade had to keep in pace with the progress on site. The building was opened in September 2009.