Architect and Builder Apr/May 2018 | Page 60

can be used as additional lettable space for larger events requiring outdoor space. While Salazar Square is currently used as on- grade parking, there is development all around it. It is hoped that the square will eventually become a contained public square, lined with activity. As such, a glass connection in the ground floor halls and a balcony in the upper halls offers the chance to link to this space. The space between the hospital and the CTICC 2 is the main service access to the halls. Work in this area is incomplete and will be undertaken as a second phase of construction. Architectural Features The halls are wrapped in a sandstone cladding. The main concourse features a performance glass façade and is covered by a flat roof. Solar control is dealt with by slatted canopies and timber balconies on the glass façade. A large sawtooth roof provides natural light to the public concourse. Extensive use of steel in the concourse façade allows the structure to be expressed as light and clean. Challenges The main challenge on this site was to fit the required brief into the limited site. The requirement 60 for minimal columns in the halls necessitated very large spans, further complicated by the loading requirements which are higher than normal due to the nature of possible exhibitions. A double basement below the building required detailed engineering including dewatering, significant retaining structures and access in a tight site. The tunnel which provides a service connection between the old and new buildings had to be inserted below a huge storm water culvert which is in the middle of the Heerengracht. The sheer scale of the building – both levels of hall are the size of a rugby field and at least 7,5m high - meant that services were highly complex. In order to ensure minimal direct solar pene- tration through the sawtooth roof, the sawtooth structure was rotated through 45º relative to the buildings’ structural grid. This was both an engineering and architectural challenge. Materials Structurally, the building is a composite of reinforced concrete and steel. Natural materials were used as far as possible, but were limited by anticipated maintenance, fire requirements and, of course, costs. All finishes and fixtures CTICC 2