The joy of decks

Was it revolution or evolution that architect CZWG had in mind when it laid out the plans for Red Square, a live–work development in Stoke Newington, north-east London? As you turn off the Victorian terrace that leads to the scheme's blood-coloured buildings, slung across with bridges and gangways, you could be forgiven for thinking the existing order had been violently overthrown. But once the initial impact of the quirky architecture has faded, you might notice some old-fashioned ideas at work. Not only does the £9m project aim to revive the 1960s dream of streets in the sky, one of the inspirations behind it was that hallmark of the arch-conservative, the Kensington-style mews.

The scheme has high density with 114 units set in four blocks, that zig-zag around a 0.8 ha brownfield site. The mews references come in the narrow cobbled roads between them. Each building is capped with a barrel-vaulted roof, and has a back that unexpectedly slopes outwards to form a kind of skirt.

This draws in light to the interiors, but the odd effect of the angled wall also shows CZWG's taste for unconventional design solutions. The firm's other London projects include The Circle, an ink-blue housing development in Butlers Wharf, and Cascades, a wedge-shaped apartment block in Docklands.

It was this track record of idiosyncratic design that attracted builder-developer Ballymore. "We thought they had the right vision to do something different; something that had impact," says spokesperson Andy Coville. This inventive tradition helps explain the strange set-up of Red Square's live–work units. Each consists of two storeys with work space at ground level and living space above. The 4 m wide duplexes function in a similar way to self-contained terraced houses. But the decks and their interconnecting bridges, which provide access to the upper residential level, separate the living and the working elements while linking the units of each.

Rex Wilkinson, a partner in CZWG, sees this as the key to the scheme: "If you're working from home it can be lonely, so we thought it would be better to build in the sense of community.

We wanted it to be fun. "

He says the design looks forward, trying to address the growing culture of home-working: "We hope we've provided planners with a model," says Wilkinson. But the solution looks backwards, too, taking on the familiar idea of the medium-rise estate in which cars and pedestrians are segregated.

Wilkinson was conscious of the failings associated with deck-access housing, which were held partially responsible for the breakdown of social behaviour in many council estates during the 1960s and 1970s. The links between access design and antisocial behaviour became the subject of intense scrutiny, with sociologists concluding that the ill-defined "semi-public" nature of the spaces – a cross between the public domain, like streets, and private property, like front gardens or driveways – meant that normal patterns of space use broke down. This was compounded by the fact that the decks had multiple points of access, and suffered from poor levels of surveillance from dwellings. The result was that potential troublemakers were unlikely to be spotted or challenged by residents.

At Red Square, various tactics have been employed to avoid these problems. First, there is just one main point of entry to the development. Second, the layout of the decks mirrors street-level routes. "The trouble with previous balcony accesses is that they did not follow the street pattern," Wilkinson argues. The decking acts as a fringe to each building, crossing from one block to another only when necessary. "Our system makes the two levels work together as one coherent public space," says Wilkinson.

The third tactic was to keep sight lines and movement at ground level as uncluttered as possible. The gangways are supported by slender v-shaped struts attached to the walls above head height, rather than by columns on the ground. The design of the bridges also avoids stealing space from below. Wilkinson has used shallow arches that push against the upper storey walls to support crossings, that are set at angles to suit the flow of movement.

Light materials have been chosen for the elevated paths. Rather than cubic concrete forms that pen people into their designated space, Wilkinson has used balustrades of narrow steel bars and cables with warm timber planks underfoot. These planks have narrow gaps that, together with open steel grilles running along the sides of the buildings, allow light to pass through.

Although the site is connected to the nearest residential street only by a thin umbilical passage, it was important to both the architect and Hackney council that the square not be a disconnected enclave. On the corners of the site, gaps have been left to link the inner area of the estate with its neighbours. This means the curved shapes of Red Square's roofs unexpectedly overlap with the corners of housing blocks or the top of a school. At one point, a perforated steel sheet is used to both screen and link an industrial building that backs onto the site. Similarly, the barrel roof on one block has been chopped off so as not to shade the housing behind. This public-spirited approach works well, evoking the sense that Stoke Newington is a continuous urban fabric of which Red Square is merely a part.

The question of context also defined the project's colour scheme. According to Wilkinson, the surrounding roads "have all the reds in the world, so we chose these colours" – deep red and peach –

"to slip into the urban scene". For all the attention-grabbing architecture of CZWG's design, there is a genuine politeness about the project. Where the new buildings with their rendered blockwork exterior are in danger of clashing with materials of neighbouring buildings, there is a willingness to be flexible. "Where we reach brickwork, we have gone brick," says Wilkinson.

This preparedness to actively respond to the site is something that gives the project a feeling of movement. The walkways around the square rise and fall as they meet discrepancies in the height of the buildings. But the ramps and steps required to deal with this give unexpected fluidity. The zig-zag plan makes for jaunty combinations of angles, continually shifting the compositions of curved roofs and bridge arches.

But the unusual-shaped units were not as much fun for executive architect Crossan and Sharma, which helped draw up construction plans in the later stages. "It wasn't just 114 identical units," says project architect Brian Gannon. "About 90 are similar and the rest are weird shapes that had to be individually tackled. They take you round corners and that required non-standard solutions." This did mean that some of the original design concepts were changed. For example, the open-plan interiors, designed for free user interpretation, have been compromised by partitioning.

Although the work space on the lower level is still pretty flexible, the second storey has a more typically domestic arrangement. The exception to this is the mini-mezzanine, formed by a raised platform set near the barrel-vaulted roof. This is designed to catch much of the direct light from the top windows while the curved roof bounces the rest into the room. It is a subtle effect that shows up the conventionality of the other rooms. "I suppose it's just part and parcel of a cost-driven exercise," says Gannon. Or could it just mean that even designers have to accept a little evolution?