A collaboration with the artist Mark Wallinger, this pavilion for the National Trust marks the signing of Magna Carta in Runnymede in 1215. Set out in cubits, the oldest – and most human – unit of measurement, it is constructed from rammed stone and sits among oak trees in a grassy meadow above the floodplain of the Thames.

Two walls, slotted with cubit-wide holes for light, enclose a central space circled by a bench. In the centre, under an oculus open to the sky, a pool of water reflects back the words of Clause 39 of the charter, which introduce the founding principles of common law.

A grassy swale outside helps to protect the ancient landscape – a Site of Special Scientific Interest – from flood damage, allowing water to dissipate naturally rather than flooding.

Winner of RIBA National Award 2019.