20 OLD BAILEY.

A landmark cut-and-carve refurbishment of a 1980s office building opposite the Central Criminal Court in the City of London. Delta Facades installed the new facade, curtain walling and atrium glazing package, transforming the building into a 360,000 sq ft contemporary workplace.

20 Old Bailey occupies a prominent island site in the western quarter of the City of London, directly opposite the Central Criminal Court. The project involved the deep refurbishment of a 1980s office building, including the reconfiguration of the existing atrium, the removal and remodelling of cores and a complete new facade at the front of the building. Delta Facades was appointed to install the external envelope package: new curtain walling, high-performance windows and the atrium glazing that redefines the building's entrance experience. Working within a live City environment, the installation had to be sequenced around retained structure, tight logistics and the exacting aesthetic demanded by the building's high-profile location.

Delta Facades carried out detailed survey and setting-out of the retained structure before releasing curtain-wall and window frames to fabrication, ensuring every bracket aligned with the existing slab edges and core openings. The new front facade was installed from a combination of mast climbers and mobile access platforms, working floor-by-floor to close weather-tightness before internal fit-out advanced. Atrium glazing was installed after structural modifications were complete, using temporary works and edge protection to safeguard the retained finishes below. Thermal breaks, cavity barriers and acoustic seals were installed at every interface, with witness checks before closure and hose testing of representative areas to verify weather performance.

• →Installing a new facade onto a retained 1980s structure with altered core positions and atrium geometry
• →Coordinating curtain-wall and window interfaces with the remodelling of building cores and the reconfigured atrium
• →Working on a prominent island site opposite the Old Bailey with restricted deliveries and live pedestrian routes
• →Achieving modern thermal and acoustic performance through the new envelope while respecting the existing frame
• →Sequencing installation around a busy City office refurbishment programme with multiple trade interfaces

• — High-performance stick curtain walling to the new facade
• — Thermally broken aluminium windows
• — Structural and framed atrium glazing
• — Acoustic laminated and low-e double glazing
• — Facade interface membranes, cavity fire barriers and stainless steel fixings