Structural Engineer: Fluid Structures
Client: City of London Corporation
Text description provided by the architects. Portsoken Pavilion is the centrepiece structure in a new landscaped public square commissioned by the City of London Corporation that has replaced a former gyratory and subways. The small building is a part of a larger civic aim to provide space for events and leisure, improve wellbeing and provide natural surveillance.
The new ‘Aldgate Square’ is one of the largest new public spaces in London’s Square Mile and improves the connection for the two distinctive listed heritage buildings that sit either side of the square: the St Botolph without Aldgate church and Sir John Cass’s Foundation Primary School.
Make Architects was briefed to create a new pavilion to sit proudly in this new landscape. It was to have an aesthetic relationship with their RIBA Award-winning City of London Information Centre adjacent to St Paul’s Cathedral, which was also commissioned by the client.
This latest pavilion picks up on the asymmetrical angles of its predecessor, with an angular monocoque structure that folds down to meet the ground at just three points, with glazing in between. Corten cladding panels form a rigid structural skin, a faceted surface that reduces the overall profile of the pavilion and provides its character. The channels created by the layered cladding are also functional, allowing the rainwater to run down them into discreet drains located where the steel meets the Yorkstone paving.
The warm tones of the weathered steel chime with the brown brick of the Grade I-listed church and the red brick Grade II-listed primary school. Over time the steel will darken and provide an earthy, complementary counterpoint.
Designed parametrically, the pavilion’s form has been carefully designed with respect to key pedestrian approaches to the new square. As such, it has no rear, and its three glazed elevations provide clear views into and through the structure and deliver natural surveillance, as well as entrances into the pavilion on all sides.
Internally the bands of the cladding are mimicked on the soffit, with layered geometric white laminate timber panels, which have punched slots to aid the acoustics and, when up-lit at night, provide a glowing effect to the whole building. Two large asymmetrical rooflights sit over the central counter to draw light into the building. Outside, the roof overhangs the entrances to allow seating to spill out.
It is a single storey above-ground but has utilised part of the former subterranean tunnels to accommodate a basement level for plant, back-of-house facilities, kitchens and toilets. This has significantly reduced the quantity of land needed above ground and therefore delivered more public space for the gardens.
The constant temperature of the concrete tunnels also work to help regulate the temperature of the building: air is drawn through the tunnels and up into the café, heating it in the winter or cooling it in the summer. The large overhangs on the roof are also attuned to the orientation of the sun and provide solar shading to the interior at peak times of the day.