Urban flagship

With its extraordinary sculptural forms, this £30m luxury housing development is certainly a match for Foster and Partners' Albion Riverside and Richard Rogers Partnership's Montevetro. But its 255 apartments are London, let alone on the Battersea riverfront, but in the small regional city of 's-Hertogenbosch in the Netherlands. Although Armada was developed by Dutch housebuilder Credo Integrale, part of the Wessels group, it can claim one vital British connection: it was designed by architect Tony McGuirk of Building Design Partnership in London. The British influence has clearly done nothing to alienate local people. In January, it was voted by the Dutch public as the most loved building erected in the Netherlands in the past three years.

Armada is the eye-catching centrepiece of one of Holland's most ambitious urban regeneration schemes. Named Paleiskwartier, or Palace Quarter, it is developed by a public–private partnership that includes the council and the Wessels corporation. The whole regeneration scheme was masterplanned by the Dutch Urban Design consultant, Khandekar, which also oversaw the limited design competition for Armada.

The competition brief drawn up by Khandekar was relatively prescriptive. As it lies within half a mile of the historic city centre, the whole Palace Quarter was planned by Khandekar on the lines of traditional cityscape with high-density, mixed-use buildings on a rectilinear street grid. But when it came to the Armada centrepiece, Shyam Khandekar, the masterplanner's senior partner, wanted a contrasting change of forms, style and atmosphere. The brief called for apartment buildings designed "as houses that contrast in a delicate way with the perimeter blocks around the park and will continue to radiate warmth and quality over the years." It also stipulated pairs of free-standing blocks that would break with the format of square doughnut-shaped blocks enclosing communal courtyards that make up the rest of the regeneration scheme.

McGuirk's scheme captures the lively spirit of the competition brief with aplomb.

The sculptural blocks, curvilinear on one side and angular on the other, have a spirited, dancing character quite unlike the stolid, four-square doughnut blocks alongside them. The stainless-steel facades belly outwards before swooping up and over the roof in one continuous curve. Their edges also project beyond the flank walls on either side like giant elephant ears. At the same time, these stainless-steel shells, all smooth, curving and shiny, are punctuated by square windows and even more so by slender balconies that project outward like open flaps. The other sides of the blocks are quite different, being mainly composed out of flat vertical walls arranged in angular configurations on plan.

Also unrestrained is the rich mix of materials and colours. As well as the silvery stainless steel of the curved facades, there is two-tone brickwork arranged in wave patterns, natural cedar boarding, white render to the lift towers, white painted brickwork behind the access decks and large expanses of clear-glazing. In fact, whole walls are made up of sloping panels of clear glass, though these are not external walls to the flats but transparent screens to their access decks. Near the main entrances rise stair towers encased in steel grilles. These have been painted a different colour – turquoise, green, red and purple – for each block so as to be instantly recognisable as an identification mark – dubbed by McGuirk its "urban doorpost".

The most compelling aspects of Armada's strikingly complex forms are the steel breastplates, which proudly bulge and gleam and are best viewed from the south. Unfortunately, the main approach route is from the north, from where the appearance is a more uncomfortable conglomeration of polygonal shapes and contrasting materials, with the clear-glazed window walls to the access decks adding a slight frigidity.

The dramatic appearance of the blocks was inspired, so McGuirk explains, by environmental and social considerations as much as by aesthetic ones. On the environmental side, McGuirk noted that the site, in its typically flat Dutch setting, was buffeted by prevailing south-westerly winds. Accordingly, he moulded each building like a single house, rather than a block of flats, by curving the smooth south facades up and over the roof so as to channel wind flows across them with as little turbulence as possible. Likewise, the protruding elephant ears on either side reduce wind eddies at each corner.

They sold so fast we had to build them quicker than we had planned

Joop van der Veer

On the same south side, the generously sized balconies serve as sun terraces. The blocks have been carefully orientated and positioned so that the terraces, living rooms and principal bedrooms on the same side all enjoy maximum sunshine and long views across town to the Countryside.

As for the social aspect of the design, this relates to the communal access to the flats. In contrast to the conventional arrangement of flats opening off internal lift lobbies, the lifts open out on to outside access decks. These are intended by McGuirk as proverbial streets in the sky, or semi-private verandahs with enough space and daylight for residents to socialise with their neighbours. The concept was introduced at the Park Hill council housing estate in Sheffield in the 1960s, where they were so windy that the reality did not live up to the theory.

At Armada, McGuirk has made his streets in the sky more amenable to neighbourliness by adding two new elements. Instead of opening directly off the communal access deck, the front door of each flat is reached by a short linking bridge, which adds a buffer zone of defensible space. Added to that, the access decks are sheltered from the wind, but not the daylight, by window walls of clear glazing on the outside. "We wanted them light and airy," explains McGuirk, "and the window walls turn them into wintergardens and social areas." Admittedly, the window walls include large gaps for ventilation, which leave the access decks more than a little breezy in winter. On the brighter side, they enable pot plants to be cultivated on the decks and offer splendid views of the whole complex including the communal gardens and water basin below, turning the whole complex into what McGuirk calls a "vertical garden city".

The water basin stretches for 400 m all along the east side of Armada. Though it could be mistaken for a disused canal basin, it has been newly created as the Palace Quarter's central landscape amenity. It also conceals two more practical functions. It covers two levels of basement car parking, successfully ridding the ground level of deserts of parked cars. It also serves as a natural heat sink, from which the district heating system can draw off heat in winter and coolness in summer.

A more accessible social amenity is made up of the communal landscape gardens surrounding each block. The communal gardens reach right up to the sun terraces of the ground-floor flats, which are no larger than those on upper floors.

As for the flats themselves, they are, to say the least, spacious, ranging in floor area from 110 m² to 200 m² for the penthouse maisonettes, and stretching through each block from front to back. According to the developer, residents are typically well-to-do couples, either professional 30-somethings or 50-something empty-nesters. With few children to cater for, living, dining and kitchen areas have been amalgamated into a palatial open-plan hall with south-facing windows. Beyond it stretches the sun terrace as a generous outdoor room.

Predictably, building Armada was not cheap. Joop van der Veer, Credo Integrale's project manager, reckons unit construction costs amounted to £1000-£1070/m² (excluding car parking) – up to one-third higher than the cost of the Palace Quarter's perimeter blocks. He also reports that the design-and-build contractor, De Bonth van Hulten, balked at the more unconventional elements, such as the double-curved stainless-steel cladding, which had to be fully profiled in assembly drawings.

Given that Dutch housebuilders are famous for building to budgets quite a bit lower than in Britain, it is remarkable that Armada escaped without being value-engineered out of existence. Though BDP was novated to the design-and-build contractor, McGuirk attests that the completed product matches the ambitious competition design. To his surprise, the contractor even raised the specification on certain components, such as supplying windows and chunky balcony handrails in tropical hardwood.