Bayside, Worthing

“What jumped out at us when we looked at the site was that sits at the moment where the town beach starts,” says Jonathan Stern, associate director at Allies and Morrison. “If you look at a map, it’s precisely where the main road hits the beach.”

Stern is describing Bayside, a wavy 15-storey residential tower on Worthing esplanade. The wider project contains 141 homes of a mix of tenures, predominantly in a U-shaped arrangement of six- storey buildings. But it is the 52m tower – the tallest building in the town – and specifically its cloak of undulating concrete balconies that has really shaken up the seafront.

Not that the idea was to undercut Worthing’s reputation as one of the south coast’s more genteel retreats, Stern adds. Rather, it was to strike a delicate balance between fitting in and standing out. “There was an aspiration from the council to produce a marker building, and it’s a gateway into Worthing, and we felt something special could happen there,” he says. “But then, if it’s going to be a taller building, how do you make that work in the context of a historic seafront?”

The answer was to let the balconies do the work: “to read as the building and make the architecture”. Inspiration came from the fine metalwork verandas of the bow- fronted Regency terraces that curve along the seafront, while the fluid form owes something to Wells Coates’ art deco Embassy Court in Brighton, a few miles down the coast.

The deep balconies solve another problem too: “The question was, how do you make a building that is essentially very highly glazed, to maximise the sea views, feel like a building, not just a glass block?”

The balconies wrap around each floor in a continuous band of 225mm-thick reinforced-concrete and white metal railings. The storeys alternate between a regular 2.5m-deep projection, and an undulating form that cinches in at the middle of each elevation before bulging out in 3m cantilevers at each corner.

This serves the purpose of drawing light inside while giving each apartment both double-height and sheltered outdoor space. “There’s a sense of enclosure, which you need right on the seafront; however, where it cantilevers, you really feel like you’re standing on the beach with nothing above you,” says Stern.

The soffits have been left exposed, in the knowledge that less hardwearing finishes could quickly look shabby in a marine environment. “We wrote a very robust specification for the concrete, including the formwork,” says Stern, “and spent a lot of time working with the formwork contractor to get the board layout working.” Phenolic- faced MDO ply was used, with sealed birch ply for the balcony edges. The boards varied between 12mm and two layers of 6mm to achieve the various radii.

Each elevation has one movement joint at the centre and the balcony structure has been kept to a minimum – a single 300mm- diameter in-situ concrete column picks up each corner. To keep the slabs as thin as possible while avoiding deflections, each one was pre-cambered – a complex detail that had to be added to the formwork design. “It was important that there weren’t any visible ridges where the camber was introduced,” says Stern, “so it’s a uniform pre-camber around the whole building rather than just locally where the slab might otherwise have significantly deflected.”

The exposed tower frame uses a 40% GGBS mix, reducing embodied carbon. This also gives a light, warm- coloured tone to the soffits – more light cirrus than leaden storm clouds – mirroring the watercolour wash of the endless Channel skies.

Photos Tim Crocker