An iconic National Grid electricity substation in the center of Sheffield, UK, has been floodlit to highlight it as a gateway to the city and celebrate its design merit. The award-winning substation was built in the1960s and designed by Sheffield architects Jefferson, Sheard and Partners. Bryan Jefferson, who led the original team and is a former RIBA president, switched on the floodlights as part of Sheffield’s Urban Design Week.

The National Grid substation, which houses the 275-KV electricity supply to the city, is an unusual construction. Most electricity substations are built on open sites with landscaping and small auxiliary plant buildings. However this substation is right on the City’s ring road in close proximity to people and on a small site.

Bryan Jefferson explained the design challenge: “In terms of the internal space, it had to be the size of a cathedral, but the heavy loadings of the transformers and switchgear meant that the construction had to be reinforced concrete with special cladding to provide sound insulation.”

Bryan had visited Japan in the early 1960s and had seen the work of Japanese architect Kenzo Tange who designed many of the Tokyo Olympic buildings. This proved an inspiration in putting together the design for a large building with human proportions. This resulted in the use of heavily reinforced concrete with a very clean line to the frame of the building.

“We also used Cornish granite as the aggregate and when the concrete was washed down the granite quartz showed through and created a gleam to the surface. It had a self cleaning property which kept it looking good.”

An unusual feature of the substation is the escape staircases at each end of the building which were designed as independent structures linked with the main building at each level. The building gained considerable critical acclaim and was commended in the Financial Times Industrial Architecture awards in 1968.

The floodlighting of the building was designed by Keir with the emphasis placed on low energy consumption. The lighting scheme includes 64 lighting fixtures at two levels on the exterior of the building providing 100,000 light emitting diodes (LEDs) which have a life span of between 20 to 25 years. Contrasting internal lights have also been placed in the glazed stairwells.

The lighting up project was organized by National Grid and Sheffield City Council with the aim of creating a dramatic and artistic focal point on the City’s ring road as well as transforming the after dark appearance of this gateway into the city centre. The council has already won awards for the lighting up of the city’s Peace Gardens and Station Square.

At the lighting up ceremony Bryan, now aged 82, said the building had remained close to his heart. While the modernist design might not be to everyone’s taste, it had stood the test of time and was still fit for purpose. “While many younger buildings have been demolished, I’m very proud to see this is judged worthy of being floodlit.”