A major internal reconfiguration and fit-out of an existing gallery space in central London to provide a new home for leading contemporary art gallery Pace.
While the existing infrastructure was retained, the internal volumes were extensively reconfigured to improve the gallery’s flexibility and shape a space better suited for the gallery’s polyhedric activities. The design includes two new galleries, plus an additional one at basement level, two private viewing rooms, and a set of workspaces.
A new lift was added within an existing staircase improving accessibility to the gallery space and allowing for easier art handling. This made it possible for the lower ground floor to become a new public space.
The main intervention to the existing structural frame was cutting a new large opening into the ground floor slab to allow for a new staircase. The ground floor slab was modelled using Finite Element Analysis (FEA) software. Having obtained the original structural drawings, our team advised on the location and geometry of the new void.
The new staircase is a striking element of the renovation. Made with waxed raw mild steel, it vertically connects the two floor levels improving staff and visitors’ movement throughout the building.
The stair is configured with three flights between two intermediate landings. The bottom landing is supported on the basement slab whilst the middle landing is hung from the ground floor and supported on a slender wall panel. Flights were designed as prefabricated treads, risers and stringers which could be assembled along with the balustrade panels on site.
The stair balustrade was designed as a sandwich with three layers of 6mm steel plate with the middle panel offset to create a continuous rebate detail across the top of the panels. The balustrade panels were integral to stiffening the stair to mitigate vibration and conceal fixings between elements. Prior to fabrication, a number of 1:1 samples were produced to test welds from both structural and visual perspectives.
Steel hollow sections were integrated into the shallow middle landing to resist the high torsional stresses generated at the intersection of the upper and lower flights.
Balustrades around the stair at ground floor were designed as cantilevers with vertical spacers welded together in-situ at joint locations and a horizontal spacer panel to the top edge. This was installed on site, to transfer shear between panels and avoid differential deflection. The cantilever was achieved with fixings anchored to the top and bottom of the existing slab with the balustrade extending below the slab soffit to the dropped ceiling below.
This meant that the analysis model could be updated to suit the fabrication proposals—adding in linear releases where elements were to be welded on site, but only sufficiently to align elements but not pass the required forces. Slender panels required buckling analysis on balustrades, especially the tall wall elements which had high compression stresses from the middle landing. Vibration was also a concern, and footfall analysis highlighted peaks at the middle landing. Hollow sections integrated into the floor plate increased stiffness and mass, whilst concealed fixings were integrated into panels so additional support could be taken from the ground floor slab edge.