Raingardens retrofit at Basildon hospital - light case study

Where

The raingardens retrofit at the Cardiothoracic Centre of Basildon University Hospital forms part of a series of European projects under the SPONGE 2020 initiative (funded by Interreg 2 Seas) which is part financed by the European Regional Development Fund. The project set out to increase “resilience against surface water flooding” through innovative design solutions, whilst simultaneously improving the amenity value of the two courtyards at the hospital.

The two courtyards were originally comprised of paving slabs and gravel, with no vegetation. Numerous downpipes along the walls of the courtyards directed water from the large hospital roof directly into the underground drainage system. Consultation with patients, visitors and staff at the hospital also identified that there was too little seating in the courtyards, that shading was lacking during the summer months and that people would like the courtyards to incorporate planting and become greener environments.

The SuDS design development focused on decreasing the paved area, introducing raised planters to allow rainwater from the hospital roofs to be diverted away from the underground drainage system and transforming the courtyards into green amenity spaces. As one of the courtyards is located adjacent to the existing café at the Cardiothoracic Centre, the design focused on the need to provide space for both exterior café seating, as well as fixed seating to allow people not using the café to enjoy their lunch and coffee breaks in the courtyard. The second courtyard is located next to the cardiac rehabilitation gym and a visitor reception, and was designed to provide three interlinked spaces; these included a ‘cool down’ area for the adjacent gym, a space to allow the internal waiting area for the adjacent reception to be extended outdoors and a quieter, more private space for patients and relatives.  

As access to the courtyards is restricted (due to their location within a busy working hospital and the physical dimensions of the courtyard entrances), the reuse of the existing courtyard materials formed a key principle of the sustainability aspect of the SuDS design. All existing materials within the courtyards were successfully reused in the design, including gravel, concrete paving, statues and benches, as well as other existing materials which were incorporated within the walls of the new gabion planters. The existing paving was restored by thoroughly cleaning it and relaying it to a new pattern, incorporating a new edge detail, thus making it unrecognisable as the original paving. The paving was also laid to a specification that promotes natural drainage, by allowing water to pass through the joints between the paving slabs and into the granular sub-base below. The gabion planters and new seating were designed to be brought in as smaller ‘flat-packed’ units and assembled within the courtyards, which successfully minimised disruption to the hospital as a result of the construction works.