The Ark acts as an outpost for the Garden Museum, announcing its presence and creating visual links between the spaces it serves. It is placed on the South-Western boundary of the site, a wedged shape projecting a ‘frontispiece’ wall towards the river. This catches the eye when coming across or along the Thames and directs the gaze into the depth of the site, towards the museum and its new gate. At it’s narrowest point, a sundial tower marks the views along Lambeth High Street and Lambeth Road. The structure acts as a barrier towards the latter, providing intimacy for St Mary’s gardens.

While honest about its utilitarian purpose, the building helps tell the story of gardening history in Lambeth and enriches the quality of the public realm. The great wall facing the bridge and field panels towards the garden, feature signage and motifs of Tradescantian rarities which are cast in low relief in rammed hempcrete walls and suggest a cabinet of curiosities. A long bench within its outer skin, faces the green.

The volume is split in two by a private courtyard with the entrance and the tool shed on one side and the changing and tea rooms on the other.

The proposed material palette reflects the monumental surroundings. in lighter, humbler versions: Rammed hempcrete reflects the stone of the church; a clay ridge tile lattice matches the colour of Morton’s Tower; the dark blue of the metal work of Lambeth Bridge is reflected in the stain of the timber frame.