Channel 4 Building

Channel 4 is a British public-service television broadcaster which began working on 2 November 1982.
Since 1994 the channel has occupied distinctive, purpose-built headquarters at 124 Horseferry Road, Westminster. Designed by Richard Rogers Partnership with structural engineering by Ove Arup & Partners, its 15,000sq metres architecture was constructed between 1990 and 1994. Twin four-storey office blocks arranged in an L shape are connected by a curved front with a dramatic concave glazed wall.

The entrance, the most striking space in the building, is defined by the first hanging curved curtain wall in London, rising the full height of the building. This atrium forms the main entrance space to the building with glazed walls that look through to the offices. Tiers of lightweight walkways at each level allow access from one wing to the other and animate the space. These walkways are formed from concrete and punctured by glass lenses that serve to create a dynamic geometric pattern when viewed from below.

Seen from the exterior, the entrance is flanked by two towers. The first accommodates a bank of lifts and services. The second tower is composed of a stack of meeting rooms, expressed as individual boxes supported on steel portal frames. Between the two towers the stone-paved public piazza rises gradually from street level to the main entrance. Here, a glass canopy hovers over the piazza, drawing visitors across a glass bridge towards the entrance. The bridge traverses what appears at first glance to be a pool, but is in fact the oculus that defines the circular foyer of the cinema below. From the cinema foyer, looking back up towards the street level, glimpses of the soaring glass wall and people crossing the glazed bridge provide an unconventional worm’s eye perspective.

Since I have been in the UK, I have observed quite a few impressive bespoke curtain walls.  This one takes the prize as the most complex piece of glass structural engineering I have ever seen.  The entire wall is supported by tie rods which are hanging (ie not deadloaded).  There was some serious vector analysis that went into this design.  Par usual, I had a run in with the guard dog, who chased me away as I approached the entrance for a closer and clearer view of the support structure.  I suppose I should have called the public relations office to arrange a tour....