Although it is a Suburb and not a self-sufficient community, Sir Raymond Unwin intended to give Hampstead Garden Suburb a distinct identity as vivid as the medieval villages which have now been absorbed into the built-up area of London. His love of Hampstead itself, no less than his study of medieval German cities, led him to place his buildings in such a way that they grew out of the contours of the ground, almost as naturally as the hedgerow trees which he was so careful to preserve. The Old Suburb, planned in detail under Unwin's direction before 1914, nevertheless has a clear-cut, simple structure underlying what appears at first sight to be random.
There were four main elements in Unwin's layout:
First, the eighty acres of the Heath Extension which had left room along its edge only for a rather narrow strip for houses, along Hampstead Way and Wildwood Road.
Secondly, visual "capture" of the commanding heights on which the central squares and public buildings were erected divided from the Heath Extension by the dramatic boundary of the Great Wall.
Thirdly, the relationship between the Suburb and the approaches to it from the surrounding main roads, along which Unwin designed a series of gates, with specially dominant groups of buildings marking the entrance to the Suburb.
Fourthly, the achievement of an intricate balance of different types of house for different classes of people, arranged in a sequence of gradations in size from the mansions in the south to the artisan cottages in the north - a gradation which succeeded in keeping the classes just sufficiently apart from one another to enable the larger houses to be commercially viable.
Many groups of houses were arranged to command a view down roads, at the same time using the buildings as terminal features in street pictures. Both on account of the houses themselves and to produce a satisfactory effect in the streets, special attention was given to the planning of buildings at road junctions and the bends of the roads. A great deal of attention was also paid to the grouping of houses along streets. This is referred to in Unwin's book "Town Planning in Practice" where, in 1909, he wrote: "In residential districts one of the greatest difficulties to be contended with is the constant multiplication of buildings too small in scale to produce individually an effect in the road, and every opportunity should be taken to group buildings so that units may be produced of large scale. Even where it is not possible to avoid much repetition of semi-detached or detached houses, they should be so arranged as to give some sense of grouping. The setback of three or four pairs of houses and the arrangement of a continuous green in front of them, with the proper treatment of the house at each end, which are set forward again to the building line, will of itself produce some grouping ... and in many other ways, especially where it is possible for the site planner to be in touch with the designer of the buildings, much may be done to produce interest and variety in the street pictures, while at the same time maintaining the general sense of unity which is usually so wanting in modern suburban roads ... The tendency of the modern individual has been to build his house in such a way as to emphasise its detachment and difference from all its neighbours, but no beauty can arise from the mere creation of detached units: the result is bound to be monotonous and devoid of beauty." In the Hampstead Garden Suburb, Unwin practised what he preached. The variety of groupings of houses is a reflection of the skill of the architects who built an estate of 240 acres in a few years.
The variety and picturesque quality extended from the different groups, and the different types and sizes of dwelling demanded by the principles of the founders, to the detailed design of the houses. The picturesque was not restricted to the domestic architecture. The club house on Willifield Green (destroyed in the Second World War), the shops and flats in Temple Fortune, and the Great Wall along the edge of the Heath Extension all suggest German precedents, especially from mediaeval Rothenberg and Nuremberg, which Parker and Unwin so greatly admired. "The aspects of the mediaeval German town gave nourishment for the romantic sentiments of the cool, organising Englishman".
The most formal part of the Garden Suburb is Central Square. This was laid out and the buildings designed by Edwin Lutyens. The centre was conceived as an impressive landmark, a gesture to the idea of community but of limited effect as a meeting place. Lutyens' houses in North Square and on Erskine Hill are fine examples of the disciplined Georgian style but North and South Square have never been completed as Lutyens intended, nor indeed has Central Square.