The slate is displayed prominently as curtain walling, flooring and vanity units throughout the award-winning scheme, 25 Gresham Street -- a speculative office building designed by Nicholas Grimshaw & Partners for Asticus Ltd.

While honed-finished slate was used on the interior, for the vanity tops and flooring, it creates the biggest impact externally. Deployed by Nicholas Grimshaw & Partners as cladding for the facades of the 10-floor column-free office building, the Broughton Moor slate used for the exterior has a flame-textured face and honed edge.

Supplied as 30-mm-thick panels, each being 1,420 mm wide and 400 mm high, the Broughton Moor cladding has been overlapped horizontally in a way that reflects the stepped, planted terraces of the building's atrium. Each panel is emphasized by being fixed to vertical stainless steel fins, with electro-polished stainless steel brackets.

To emphasize the mid-green color of the Broughton Moor slate, the architects selected green-tinted anti-sun glass for the offices, which contrasts with clear glass used for the atrium and ground floor. The same color themes combine with the Broughton Moor slate internally, where the use of aluminum and glass also figure prominently.