We were invited by the Landscape Architect Todd Longstaffe-Gowan to design a ‘smoking pavilion’ within the garden of a private house in Zurich he was designing. This would be a shelter where it would be possible to sit and relax and admire the surrounding garden, lake and mountains whilst our clients could partake of one of their favourite pastimes without affecting anybody in the house: the old fashioned art of smoking.
Our idea was to create a simple structure sitting quietly in the garden, possessing a richness and complexity in its materiality that would develop several relationships with the surroundings. We wanted the pavilion to be a shelter encouraging a subtle perception of the garden and sunlight. We have been aware of the existence of translucent concrete since it was first invented in 2001 and it felt like the appropriate material for this project, because it allowed surrounding colours, shapes, movements and shadows to be perceived from the interior.
A garden is composed of plants and living organisms: the translucent concrete allows the pavilion to feel alive too. As light conditions change, the surfaces of the structure change, varying from heavy to light, solid to translucent, monochromatic and uniform to varied and colourful. The concrete breathes with the surroundings. In the night, walls and slabs are lit creating a feeling of lightness and giving them a fabric-like quality.
This is the first ever self-supporting translucent concrete building. A system was developed with GBA, Tall Engineers, Litracon and Hammerlein, using a new variant of translucent elements where the precast panels had to be carefully engineered to perform very efficiently to obviate the need for a secondary structure.
The casting was a delicate operation because of the combination of the dense pattern of PMMA translucent elements, the carefully positioned stainless steel reinforcement and the thinness of the panels. The final material looks very simple, but is in fact the result of precise and advanced engineering.
The pavilion is defined by five translucent precast concrete panels connecting floor, walls and roof, and yet what might be thought of as a heavy and solid materiality has been transformed into something seemingly ethereal and delicate.
TALL Engineers Structural Description
The smoking pavilion is formed of five precast reinforced concrete panels, each just 80mm thick and up to 3.6m by 2.6m on plan, with a maximum weight of 1.8 tonnes. The concrete is a special product called Litracon pXL which is made transparent by the introduction of an array of 4mm diameter acrylic rods at 16mm centres. These allow points of light to be transmitted through the concrete slabs.
The slabs were reinforced with small diameter stainless steel reinforcements, ensuring that low-cover thicknesses to the embedded steel did not lead to corrosion. The panels were craned into place, and joined with a dowelled connection system. The roof is supported along the sides of the walls, but the floor slab is supported from two strip foundations set back from the edges and cantilevers past these to support the walls.
Project Data:
Timetable: commission March 2013, start on site August 2013,
completion with landscape July 2014.
Budget: £65,000
Total Area: 8.3 m2
Client: Confidential
Photographer: James Morris
Design Team
Architect: Gianni Botsford Architects
Landscape Architect: Todd Longstaffe-Gowan
Structural Engineer: TALL Engineers, London & Hemmerlein
Ingenieurbau GmbH
Checking Engineer: HTB Ingenieure + Planer AG
Contractor: Hemmerlein Ingenieurbau GmbH
Landscape Contractor: Bahnsen Gartengestalter GmbH
Specialist Translucent Concrete Supplier: Litracon Bt=
