Through the 1960s Gibberd’s freedom to experiment with new forms of housing design and building materials continued to be hampered by the restrictions imposed by local and central government. Unfamiliar ideas were opposed on the grounds that tenants might not like them. Rising building costs and stricter cost controls ruled out the use of traditional building materials like slate or clay pantiles for roofs. And new policies such as limitations on the distance a dustbin could be carried, were developed and rigorously applied. However Gibberd was able to get permission to proceed with what the Architects Review (1966) called ‘two prongs of attack’ on mediocrity of design as he began to develop Great Parndon neighbourhood. Clarkhill involved the experimental use of industrialized building methods and Bishopsfield required modifications in building by-laws to permit an unusual house form.

Clarkhill

From the outset of the New Town programme the Ministry had required a certain percentage of ‘non traditional’ houses which used new materials and methods of construction and the Clarkhill estate satisfied this requirement. Located on the south side of Southern Way, it was a rigidly rectangular development of 200 dwelling constructed of pre-fabricated concrete panels. They were erected in part by semi-skilled workmen as an experiment to see if this would reduce costs. This is may have done, but the experiment was not to be repeated. From the beginning the development was plagued with leaks and condensation problems, the experiment deemed a failure, and it was demolished.

Bishopsfield

Across from the site of Clarkhill, north of Southern Way, is Bishopsfield. In 1961 the Board of the Development Corporation agreed to hold an open competition for the first housing development in the Great Parndon/Passmores quadrant. The winning entry, chosen from among 60 contenders, was submitted by 24 year old Michael Neylan. His concept was of a platform on top of a hill that provided space for underground garaging with a  pedestrian concourse on its roof to provide a central focal point for the development. A ring of flats surrounds the concourse, or 'piazza', with their front doors leading off it and an outer ring of courtyard houses stepping down the hill, with pedestrian lanes running between them. The blnak walls of the lanes, relieved only by the small windows of the kitchens, give it a somewhat North Africna appearance, and the development was soon nicknamed 'The Casbah'. In an effort to reduce the distinction between flats and houses, almost every dwelling was given a private open space large enough to be useful for domestic activities. The ground-level dwellings had gardens; those above had terraces. And as flats as possible were given their own front door opening directly to the open air. The development would have been impossible without some relaxation of cost limits because ‘man-made ground’ like the piazza is very expensive. Furthermore, these houses were radically different from any that had previously been built in Harlow, and their construction required some relaxation of building by-laws.

The L-shaped Bishopsfield houses satisfied the government's demand that residential densities be increased but also mitigated some of the more common disadvantages of higher density. The key to the plan was the arrangement of living rooms and bedrooms to face into a small rectangular courtyard. The design gives almost total privacy since all rooms except the kitchen face inwards to the patio. The houses are single-storied so the gardens all get some sunshine, and most are not overlooked, making it possible for houses to be packed very tightly together with no loss of privacy. The open plan of these houses was deemed so unusual that the first residents were given a booklet called ‘Living in Bishopsfield’. This not only gave advice on transport links and so on, but also on living in the new houses.

In 2008 it was estimated that  an investment of £50,000 per flat would be required to bring the 40 year-old units up to ‘decent homes’ standard. Consequently there was talk of demolishing the estate. Fortunately it has survived, perhaps because recent surveys show that 92% of residents liked their homes and 82% liked the estate. It isn’t only the residents who like the place – in 2009 the Twentieth Century Society recommended that it be awarded a Grade II heritage listing.