Restoring Preston's Brutalist masterpiece

A major refurbishment has breathed new life into the iconic Preston Bus Station and its car park

Preston Bus Station, a massive structure that combines a bus terminus and multi-storey car park, has reopened after a major refurbishment. The building is an iconic piece of Brutalist architecture. The bus station and 1,000-space car park was designed by Keith Ingram and Charles Wilson of Building Design Partnership (BDP), engineered by Ove Arup and built by John Laing. Its façade is defined by the white ‘scallop shell’ balconies formed at the edge of the parking decks that rise above the ground-floor bus station, which are designed to accommodate 80 double-deckers, lined up in two ranks of 40 vehicles along its ground floor.

The sheer scale of Preston Bus Station meant it became a local landmark and was voted Preston’s favourite building in 2010. However, the building was earmarked for demolition to make way for the council’s Tithebarn shopping centre, which was also designed by BDP. The Tithebarn plan collapsed in 2011, but the bus station still remained at risk of being replaced with a smaller interchange near the railway station. A campaign to save the bus station was launched by local conservationists, who were eventually successful in obtaining Grade II listed status for the bus station in 2013 Preston.

Angie Ridgwell, the county’s interim chief executive, said: “Only a few years ago this building was at risk of demolition. But I have learned how important it is, not only to the people of Preston, but also architectural critics across the globe who are fascinated by its unique Brutalist architecture.”

Lancashire County Council developed a £24m plan to reinvent the Preston Bus Station and refurbish the car park. A key element of the plan was the creation of a ‘Public Service Hub and Youth Zone’ adjacent to the bus station. John Puttick Associates won a RIBA-organised competition to select the scheme’s architect in 2015.

The architect and project contractors liaised with the Twentieth Century Society, which campaigns to preserve Brutalist architecture, to ensure that the look and feel of the bus station was protected. The society advised on the impact of using repair materials that are sympathetic to the building’s look and structure. “There are not many examples of Brutalist repair work, so engagement with the Twentieth Century Society was very important in terms of understanding what was required,” said John Puttick, who has moved his practice base from New York to Vauxhall, south London, during the course of the Preston refurbishment. 

“The project needed to deliver a contemporary bus station while being sensitive to the original design intent. Fortunately, much of that design intent remains relevant. The Twentieth Century Society was more relaxed about the areas that had previously been painted, but was keen for the exposed aggregate look to be retained.” The society, however, did have concerns over the possible impact the scale of the new youth zone building would have on the bus station. This led to the structure being redesigned. The youth zone is expected to be completed by 2019, subject to the planning process.

The job of restoring the bus station and car park was costed at around £12.5m. The contract was awarded to local company Conlon Construction in 2016. The county decided to follow an early contractor involvement (ECI) procurement route, allowing it and Conlon to identify key trades and plan the renovation work. The job of refurbishing the car park was contracted to Makers Construction, a specialist in renovating multi-storey car parks, which commenced work in 2016.

Good news came when surveys revealed that the structural condition of the bus station was no worse than when it was built. To assess the curved scallop edges, Conlon and Makers created a special cradle that cantilevered out from the building. It was decided to coat the scallops with an anti-carbonation paint while the exposed aggregate exterior columns were covered with a clear-glaze coating called Sikagard 680S.

The steel reinforcement concrete decks have been given more resilience through the use of an impressed current cathodic protection (ICCP) system supplied by Corrosion Protection. “It’s important for the council to have a 25-year warranty for the bus station, and the restoration methods and finishes which Conlon identified, in particular use of anti-carbonation paints and corrosion inhibitors, will allow that,” says Andrew Barrow, project manager for Lancashire County Council.

The condition of the parking decks varied because only those exposed to the elements were coated, in this case with a bitumen material. The parking levels located directly above the bus depot and other occupied spaces required particular consideration for refurbishment. The waterproofing solution had to be directly overlaid the existing asphalt substrate in order to prevent any damage to lower storeys, minimise the loss of working hours and reduce overall costs. The initial site survey established that the decks had suffered from years of heavy traffic, leaving the decks worn and bearing cracks, blisters and rucking. In some areas, repair works had also failed, leaving the asphalt pulling away from the concrete upstands.

Makers invited Triflex to provide a project specification for a waterproofing and surfacing solution for the car park. During its survey, the Triflex technical team conducted tests to determine the suitability of the asphalt for direct overlay and anticipate the level of preparation required before installation. The on-site testing established that the best solution would be Triflex DeckFloor, a heavy-duty system designed to be compatible with a range of substrates. Pre-installation works included removing the clustered blisters and shot blasting the decks to ensure the best possible adhesion between substrate and system. The DeckFloor system is cold-applied to improve safety and decrease time on-site. Being a fast curing, it could be installed in stages, allowing the car park to remain open to the public during the works. 

A major challenge was to keep the bus station and car park, which is used by 10,000 people a day, operational throughout the works. Project manager Andrew Barrow said: “It’s been challenging in that we were dealing with a listed structure and all the restrictions that brings with it. It never closed throughout the work, from the day we started in September 2016 to June this year when we completed the work. It was logistically difficult, but we got there.”

Lancashire County Council leader Geoff Driver said: “We are lucky to be standing here in the bus station. Originally, it was going to be knocked down as part of the Tithebarn development, but that collapsed. It was debated whether it should be knocked down. Preston Council couldn’t afford the resources to refurbish it. Thankfully it was listed, which effectively saved it. Something in the order of £19m has been spent to date. It is not quite finished, there is still a little bit more to be done. Yet we now have this fantastic refurbishment. And it is going to serve Preston and the people of Lancashire for generations to come.”

Architect John Puttick said: “I am really pleased with it. It’s much better, it’s much cleaner and I hope everybody feels it is a big improvement. It feels like a really safe public building and that’s really good. It is a project that has been debated for a long time before I became involved and people have strong feelings about this building one way or the other. There were always going to be some problems to deliver it. It’s been a challenge keeping the building operational while we did the work. The bus station has never closed and there has only been about a quarter of it worked on at a time. But I’m really happy with the way it has turned out. I’m really proud of this. It’s fantastic.”