Located beside London's Guildhall complex, the refurbishment of 20 Gresham Street repositions a 2008 office building through a strategy of retention, selective intervention and spatial adaptation.
Designed by John Robertson Architects (JRA), the project upgrades 5,852 square metres of office accommodation while transforming the entrance hall and basement facilities to meet contemporary workplace requirements. Rather than undertaking a complete redevelopment, the project treats the existing building fabric as a resource, preserving significant architectural elements and reducing the environmental impact associated with demolition and reconstruction.
Originally completed by KPF in 2008, the building's defining feature—a double-height entrance hall lined with a sculptural travertine wall and full-height glazing along Gresham Street—became the starting point for the refurbishment strategy. Although impressive in scale, the space had become echoey and unwelcoming, with its hard surfaces and vast proportions creating an austere atmosphere.
JRA aimed to improve the arrival experience while respecting the existing architecture through thoughtful interventions and new artwork. Central to this approach was the decision to retain, rather than replace, the extensive 40 mm solid Tuscan travertine wall and the natural stone flooring throughout the entrance hall.
The geological character of the stone informed a broader design narrative inspired by riverbeds and organic erosion patterns. By prioritising refurbishment over replacement, the project avoids demolition waste, preserves embodied carbon, and extends the building's life cycle. The retention and reuse of existing materials and building components is estimated to have saved 36 tonnes of CO₂ equivalent.
Material selection and responsible sourcing
New materials were selected with durability, low emissions and responsible sourcing in mind. FSC-certified timber joinery, veneers and doors contribute to longevity and support responsible forest management practices. Acoustic ceiling panels utilise Greenguard Gold-certified Kvadrat fabric to ensure low chemical emissions and improved indoor environmental quality.
The ceiling systems were supplied by SAS using the manufacturer's Horizon sustainable production methods, while natural materials including timber, stone and leather were employed throughout the reception space to create durable and repairable interior elements designed for long-term use.
The project balances contemporary interventions with material permanence, favouring robust finishes and high-quality components intended to minimise replacement cycles and future material consumption.
Improving performance and occupant experience
One of the immediate challenges of the entrance hall was poor acoustics, with conversations, footsteps and escalator noise reverberating around the hard surfaces. In response, JRA introduced an acoustic fabric panel ceiling system with integrated metal service channels, significantly improving the acoustic environment and creating a more welcoming atmosphere.
Stretch fabric panels form an elegant acoustic ceiling, introducing a sense of calm to the space. The sculptural benches and suspended mobile were integral to JRA’s initial concept, inspired by the architectural, sculptural and material qualities of the travertine wall from the original base building. The connection to the natural environment is further reinforced through the introduction of large living trees, which bring both scale and softness to the interior.
Andy Thomas, Project Director at JRA, said:
“JRA’s design for the new entrance hall at 20 Gresham Street aspires to create a space more akin to a gallery than a traditional reception area. Tenants and visitors are encouraged to dwell, enjoy and engage with high-quality artwork within an inviting setting. The scheme creates a distinctive arrival experience, combining a carefully considered architectural adaptation of the existing interior with dynamic new artworks. These include sculptural benches by David Worthington, developed in collaboration with Marble Projects and Bill Amberg Studio, and a suspended mobile installation by Acrylicize. A new travertine reception desk designed by JRA complements these artistic interventions."
The intervention also enabled a new lighting strategy developed in collaboration with specialist consultants Equation. The lighting emphasises the material qualities of the travertine wall, particularly within the recessed cove at its head, allowing the natural forms and textures of the stone to become a focal point of the arrival experience.
Material continuity and biophilic design approach
A key intervention is the addition of four sculptural travertine benches designed by British artist David Worthington. Crafted from a single block of stone sourced from the S.I.T.I. Travertino Toscano quarry in Tuscany, the largest bench measures up to five metres in length and weighs as much as 2.5 tonnes.
Inspired by the project's riverbed concept and the pebble-like forms within the existing travertine wall, the curved benches create informal spaces for meetings, conversation and moments of pause. Planted trees complement the stone interventions, introducing biophilic qualities and reinforcing a connection to nature within the urban setting.
Additional interventions include bespoke furniture and a reception desk fabricated from the same Tuscan travertine. Suspended above, the artwork *Cascade*, created in collaboration with artistic studio Acrylicize, comprises 188 pebble-like forms referencing fossils, river stones and the concave geometries of the existing wall. Eight golden elements highlight themes of nature, prosperity and balance, while the 3D-printed installation establishes a dialogue between ancient stone and contemporary fabrication techniques.
Sculptor David Worthington said:
“The benches at 20 Gresham Street form an integral part of the overall concept for the entrance hall. JRA originally conceived the idea of monumental benches in travertine, echoing the pebble-like scallops within the travertine wall of the existing building. My own work is inspired by the natural world and organic forms as well as being influenced by Modernist sculptors such as Isamu Noguchi. I regard sculpture and design as equal but distinct disciplines, each contributing in their own way to the built environment. In collaboration with JRA and the production team, I believe we have created a highly accessible, visually captivating and functional installation. The benches at 20 Gresham Street are a lasting connection between the natural environment and the existing building.”
Long-term flexibility
The refurbishment adopts adaptability as a long-term sustainability strategy. The basement has been transformed to provide enhanced bicycle storage, maintenance facilities, showers and changing rooms accessed via a new staircase from the entrance hall. The conversion of former car parking areas into end-of-trip facilities supports sustainable commuting, active travel and hybrid working patterns.
The upgrade of 5,852 square metres of office accommodation introduces targeted interventions with maximum spatial impact. Office Levels 4 and 5 have been delivered to CAT A standards, incorporating raised flooring, raft ceilings, upgraded M&E services and improved WC facilities.
The office floorplates are designed to accommodate future changes in occupancy and programme, allowing for cellular offices, smaller meeting rooms and split tenancies. Existing fittings and finishes were retained wherever possible and integrated into the new workspace, reducing material waste and preserving embodied carbon already invested in the building.
This flexible planning approach allows future CAT B fit-outs without major alterations to the base building, reducing the likelihood of future strip-outs and supporting a long-term, circular approach to workplace design.
