Copthorn's Challenge

"It's got the Marmite factor, hasn't it?" Neil Armstrong, marketing director of Copthorn Homes, is surveying the homes his company is building on the outskirts of Harlow, in Essex. At his back are glorious rolling fields, but his gaze is fixed on a streetscape before him. It resembles one of those trendy housing estates in the Netherlands so revered by UK architects, with its high-density terracing, eye-catching splashes of orange and downright un-English monopitch roofs.

Armstrong is adopting the love-it-or-hate-it slogan, dreamed up by the marketers of a yeast by-product, to describe the reaction of prospective buyers to the homes he is marketing at Abode. This is the latest phase of Newhall, a greenfield housing site where conventional housetypes have been outlawed. Buyers looking for a traditional detached house, garage and garden don't hang around here for long. But Abode has its fans. Twenty-five of the 82 homes have been sold, and CABE rates the Proctor and Matthews Architects design so highly it has been awarded a Building for Life benchmark, an indicator of outstanding design quality.

CABE chief executive Jon Rouse has praised the scheme not only for its contemporary design, but for the enlightened approach taken by Newhall's landowners. Abode is the second parcel of land to be released for development in what will one day be a 2800-home settlement covering 80 ha of former farmland. The landowners, New Hall Projects, which is led by brothers Jon and William Moen, are driving a design-led approach to development. The focus on design stems from their concern for the future of their family's inheritance and their disappointment with the conventional homes that the housebuilding industry produced on land they sold at nearby Church Langley.

This time around, the landowners are aiming to ensure that the homes at Newhall leave them with a sense of pride. They are imposing strict conditions on the design of what gets built on each parcel of land they sell, and in the process they are teaching the housebuilding industry a lesson: contemporary design can be applied to the large out-of-town estates where the target buyer is a middle-income family.

The architectural course pursued by Copthorn Homes and Proctor and Matthews was therefore well and truly set by the landowners and their masterplanner Roger Evans Associates. Evans' plan drew on the work of Sir Frederick Gibberd, architect of nearby Harlow New Town, which advocates humane urban development principles. Newhall has wedges of green space, a density of 50 people to the hectare and amenities within walking distance. Those influences have been woven into a PPG3-compliant strategy that was developed eight years before the government guidance came into force. The car's impact is subdued by tree planting within roads to create a natural form of traffic calming and by relegating parking areas to courtyards and rears of buildings. The street pattern, which is based on site contour lines, is permeable – with no home more than a block away from a green space – and has a clear hierarchy based on tradition rather than the demands of local authority highway engineers. "It is a spatial hierarchy rather than an engineer's hierarchy," says principal Roger Evans. "Abode runs from the grand boulevard to the mews court, so its team has had to address every level of the street hierarchy."

Along the grand boulevard, Abode is sprouting four-storey apartment blocks and terraced houses, while behind that are the mews courtyards where unit sizes range from four- to one-bedroom. Proctor and Matthews' design incorporates the parking into the mews housing by topping carports with dwellings, turning the courtyard into a close-knit and – provided the neighbours get along – sociable space. "We've made them living spaces," says director Stephen Proctor. "There is something almost medieval about the mews courtyards. We didn't want to ghetto-ise executive homes, so we have created a mix within the mews courtyards where you would normally find just over-the-garage chauffeur suites."

Overall, the scheme's density comes in at a PPG3-friendly 42-45 units per hectare, putting it in the upper range of the masterplan's density bands for Newhall, and Abode's homes are noticeably lacking in the mean, boxy rooms of many housebuilders' standard housetypes. "The challenge was to get large adaptable spaces in as close confines as possible," says Proctor. "We wanted to create lofty spaces that could be adapted over time, where people could fit a mezzanine if they wanted. We're tapping into a market that is looking at quintessentially English homes and tapping into the rambling nature of English houses." These lofty, rambling spaces are achieved by using an open-plan design with sliding partition walls and galleries, and increasing volumes to double height.

The ground floors of the houses are elevated in brick, forming a "garden wall" running through the scheme. Storey-height limestone gabion walls in front of the ground-floor elevations clearly separate the public and private realms, mark the entrance to buildings, and, more prosaically, keep the dustbins out of sight. Above ground-floor level, homes are elevated in the lightweight components of timber, tile and render. The architect designed the scheme to be produced by combining off-site manufacturing technology with timber frame, but because the timber frame industry was struggling to meet demand when Copthorn came to build, the housebuilder chose traditional methods.

Upper-floor windows have separate projecting frames delineated in white, "as if you'd marked them out with a highlighter pen," says Proctor. They, like the panels of vibrant orange render beside the windows, are designed essentially to lift people's gaze up and away from the mundane carports and garages of the ground floor. Windows are also equipped with Corbusian ventilation slots to allow air into heavily glazed rooms that could otherwise overheat in summer, while timber louvres add protection from the sun and the eyes of curious neighbours.

Corner buildings are marked out by projecting corner bay windows, which Proctor describes as "eyries", or by monopitched roofs constructed using that most traditional of English materials, thatch. "It was the first time that thatch had been used in a monopitch roof and we were advised that it couldn't be done," says Proctor. "With a monopitch you don't have a ridge and so can't go over the top; that's why we did the lead capping."

Throughout the scheme, the architect appears to be banishing the shibboleths of conventional housebuilding. Ask Proctor why he has used thatch or gabion walls or has gone with the orange from the Newhall design code devised by artist Tom Porter, and his answer is: why not? "We went to the extremes of the colour palette because we like colour. The fact that thatch is associated with chocolate box covers is neither here nor there – we're using it for its textural qualities," he says. "The materials have come from the design code's palette, and we liked the idea of traditional building materials being used in a contemporary way." The 3D quality of the homes is reinforced by the textural interplay between brick and stone, thatch and conventional tile, as well as by the projecting elements of the facade. "A lot of contemporary housing has no depth and solidity to it," adds Proctor.

Building the homes has been a lengthy task – the programme for a three-storey home extends to 36 weeks. Times have been stretched partly because of the switch from off-site manufacture to traditional build and partly because of the complex nature of the scheme. "The co-ordination of site-measured and manufactured elements has not been as smooth as it might have been. This has been a different animal to build," says Mike Page, development manager with Copthorn Homes. "As we get our heads around the complexity of it, we are getting quicker."

Maintaining the homes could be an equally time-consuming business for buyers, with so many finishes and projecting elements making it difficult to get at the facades with a paintbrush. Sensibly, Copthorn is giving buyers some advice so that Essex man can keep his gabion walls looking neat.