The Guy's Hospital was built during the 1970 to serve north London area. Until 1991, the building was the tallest hospital facility in the world. The uncommon high rise facility (generally hospital achieve efficiency in low and mid rises), was relatively efficient. This was achieved by an original design arranging separated circulation areas for clean accommodation floor-plates.
However, facade was deteriorating. Spalling was getting extensive, leaving gaps across the concrete and staining the pre-cast facade . Those conditions would have required continuous remedial work.
The retrofit plan return the building to be the tallest hospital facility in 2015. The retrofit plan was structured in three stages. A first phase contemplated stabilizing and cleaning spalling concrete on walls. Following, an outer insulated layer was incorporated to the walls. Finally, a rain-screen was incorporated as the new external facade. The system consists of folded aluminium profiles with an anodized finish. The aluminium panels will be fixed to the facade by support rails and separated from the thermal insulation layer by a void. The void will be subdivided by fire barriers at each floor to comply with fire regulations.
Similar repair and thermal improvement was carried out in the main tower. However, the new layer was curtainwalli consisting of glazing and flat-profiled anodized aluminium facing. The new curtainwall was fixed to the outer face of concrete columns. Thermally broken frames and glazing with argon filling reconfigured the system. This new skin, allowed a phased replacement of the existing internal windows. The glazing will use solar selective glass in order to minimize solar gain and optimize orientation.
The project responded to Vision 2020, the estate renewal program. With an increased lifespan by an additional 30 years, the environmental benefits are considerable. Technically, the project is an example of an intervention that allowed future internal retrofit stages to take place without compromising the operation of the hospital facility.