The Green belt concept grew out of the English Garden City movement of the nineteenth century. Although the thoughts and theory were widespread throughout the first half of the twentieth century, it was not until 1959 that green belt policy became legislative reality. The initial result was the London Green Belt: other green belts around major cities followed The predominant objective of the green belt at that time was to restrict urban sprawl, and the concept was initially well supported by citizens, planners and the Biitish government. The British government attaches great importance to green belts, which have been an essential element of planning policy for some four decades. The purposes of green belt policy and the related development control policies set out in 1955 remain valid today with remarkably little alteration. This sophisticated and comprehensive approach provided a model that many other cities around the world have since followed. Christchurch for example inherited its planning legacy from the British experience. Although first defined in 1954 as a 'non-settlement area', (meaning the same thing) it was not until the 1980's that the term 'green belt' was formally used in New Zealand statutory planning documents Since then (particularly in the later 1990's) there has been speculation that the green belt philosophy has begun to fade The green belt containment policy was designed to thwart urban spread but has instead led to piecemeal development. Essentially, this has led to a rethink of the green belt. There is some speculation that the codification of green belt policy that originated in 1955 in London is not applicable to the city of Christchurch. Furthermore, new legislation by the way of the Resource Management Act has altered the philosophies of land-use planning and encouraged a new way of thinking. This new thinking is based on sustainable management objectives and has been responsible for much of the green belt's recent decline. No longer can a single land-use tool restrict development in such a large area without considering other potential uses, while simultaneously juggling it with the sustainable management principle. Accordingly it has raised questions as to whether the Christchurch green belt concept is worth keeping, and if not, what other means are available to help continue to promote the green belt objectives that were first introduced many decades ago.