Holbrook’s proposal chimes with ideas set out in A Clockwork Jerusalem, the UK’s show at the Venice Biennale, and comments made last week by legendary planner Peter Hall, that argue for the return of long-term visionary planning in the UK.

Vision: Why Calvert?

Calvert is a small settlement built around a series of former clay pits and brickworks east of Bicester and just north of the Roman road, Akeman Street.

It lies between the green belts of Oxford and Greater London, and is adjacent to the 1970s New Town, Milton Keynes. It is exceptionally well-connected, but sparsely populated.

Without a strong topography of its own, Calvert is not a site of natural beauty, but it has started, in an ad hoc way, to establish an alternative topography – the former brick quarries are now lakes. The brick kilns have a plinth-like quality, reminiscent of those used by Robert Adam or Nash in new parts of London. In this way, the site shows signs of an incipient urbanity.

The best cities are not generic ideas played out at convenient locations, but are structured around a particular response to a landscape. Calvert is a location catalysed by two major engineering projects, which make a new city possible.

In Britain’s ancient landscape, the best sites for settlement have long been occupied. New locations need to be created with vigour.

Calvert lies at the intersection between two proposed rail projects that each restore former rail routes: the east-west rail project, which aims to reinstate the ‘Varsity Line’ linking Oxford and Cambridge, and High Speed 2 (or should that fail, the reinstatement of the Great Central Main Line, which ran, until Dr Beeching’s cuts, from Marylebone to the North). Calvert has been identified as the location for a substantial marshalling and maintenance depot for High Speed 2.

Calvert is exemplary to a number of other locations where High Speed 2 might meet regional rail networks, and where a similar approach might be considered.

At a time when government is beginning to struggle to articulate a narrative for high-speed rail investment here is an answer: the creation of a new address at the centre of a great new connected geography.

Calvert is located at an economic nexus where specialist manufacturing is in demand, driven by the knowledge hubs of Oxford and Cambridge, and the metropolitan momentum of Birmingham, Manchester and London. As with the original conception of the garden city, this presents the potential of a place of thinking, making and living – not just a dormitory town.

Nature: A Garden City in a Garden

Calvert also sits between Blenheim and Stowe, the laboratories of English Baroque and emerging ideas about landscape.

In any urban development in the UK, the debate revolves around the relationship between nature and culture, city and countryside. A new garden city implies some means of hybridising each condition – the Edenic garden and the urban necessity. The reality is generally an indistinguishable sprawl.

An alternative approach, building on this tradition, might be a concentrated city that opened onto a concentrated hinterland – a differentiation of territory, each with the best of both. As with Cambridge, St Albans, and the rapidly industrialised mill towns of Yorkshire, it should be possible to be in the city, but to walk out into adjacent countryside.

We propose a compact city embedded within an accessible and highly managed countryside hinterland, in the manner of the English country house within its estate.

The compactness of the city makes access to the city’s surrounding garden quick and easy. The elevated nature of the city gives ready access to spectacular views across this landscape and the countryside beyond.

Environmental research has revealed very little biodiversity on the site at present, and the records of the Grand Central rail line show that the route was located here because of its relative lack of occupation.

The creation of this garden would not only provide a rich and varied series of environments for the citizens of the town – and, of course, visitors – but would also increase biodiversity and provide locations for localised energy crop, food production and water management.

The Anatomy of a New City

The Open University (OU) is a radical project to widen access to learning, and is increasingly relevant in a time of marketised higher education and the development of massive open online courses (MOOCs).

As an expansion of the OU campus at Milton Keynes, the Calvert campus would intersect the Varsity Line ‘knowledge corridor’ between Oxford and Cambridge, as well as having connections to Manchester, Birmingham and London. It is a signal of major investment in green technology and research at Calvert. Like Cedric Price’s Thinkbelt, a dispersed but located university is a critical ingredient of a new city, creating a Chequers-like resource for the knowledge economy (Chequers is 20 miles away).

Metabolism: Infrastructure

The state has ceded its responsibility for food security and distribution to the big supermarkets. We are told that, with just-in-time logistics, we are three hot meals from chaos should this system falter.

A new city should be a resilient city, one able to deal with extreme weather, and have a degree of autonomy in terms of its power, food, water and waste treatment.

This area of the UK has become a territory shaped by logistics - its landscape dominated by huge sheds, data centres, and dark stores with their associated road engineering.

Calvert presents the opportunity to create a carbon-neutral city, recycling its own waste to realise energy, and storing and purifying its own water, regulated by connection to the canal system.

While not autonomous, the new city would build a strong relationship to its hinterland, using its infrastructure to create a strong character.

Heart: Civility

Truly urban with its rich mix of activities and hybrid possibilities, Calvert will be a complex, condensed structure as the ground for mediation in contrast to the atomisation of the suburban garden city, where ‘landscape’ is used to separate and create ‘buffers’.

Calvert will be a city compact enough that the town square would serve the whole settlement, with nowhere more than a 20-minute stroll from that centre point of the community. This will bring a remarkable level of activity and life not available to the dispersed and isolated sprawl of suburbia.

To avoid the stigma associated by many with new towns, it has to be remarkable (more exciting, more spectacular, more peaceful, more enjoyable) than ordinary towns. Through its spectacular section and mix of activity, Calvert will counter the crashing homogeneity of so much contemporary development.

The possibilities of super-imposition

With any finite asset it makes sense to make the most from what you have. We propose therefore to stack up the programme – to concentrate a city – to use the antisocial, space-hungry black boxes of distribution, logistics and warehousing, parking, and power generation to create a hill onto which we can graft a city (in a rather delightful way).

Left to its own devices, the market will not deliver complex and hybridised built form – it prefers to create monocultures. The state is the only agency able to create this complex, super-connected built topography for the common good.

Economics

The scarcity and high cost of land on which it might be possible to build a city suggests that, once a potential location is identified, it should be used to its full. The investment required in any new road, railway line or settlement suggests that these locations should be used intensively.

There is enormous demand for urban development to accommodate an increasing national population, changing population profile, and evolving economy. Land – particularly land on which one can build a city – is an enormously valuable and precious resource.

If land is the highest cost presented to the creation of a new national project, then it should be used many times over. Our simple observation is that large amounts of land will be bought at Calvert for High Speed 2.

The coincidence of two new railways and a new city, together with other national assets (the expansion of the Open University, the creation of public housing) makes full use of this original land purchase.

The state, using the successful model of the New Town Development Corporation, can borrow cheaply to invest in infrastructure. As with the example of Milton Keynes, this investment will not only generate economic development, but will actually create a capital receipt over time as leases are released to shared ownership trusts.

Conclusion

The Wolfson Prize prospectus asks that entrants ‘show how the city can avoid relying on a single penny of public money and be self-financing. The wealth that can be created through the building of a new city must be more than enough to develop its infrastructure’.

We believe that this fundamentally misrepresents the problem, which is that the present crisis is due to a failure of the private sector to deliver development in a sustainable way, instead creating a housing bubble.

We invert the challenge, asking rather: ‘How do you create a city out of infrastructure?’ It is only the public sector which can create long-term value in the public interest. It is only the state which could establish complex interaction between infrastructure, urban framing, and architecture of the city.

The problem is not primarily financial, but political – it is about overcoming 'nimbyism' and vested interests. Who will be bold enough to make the right choice: to make a beautiful new city that is both a joy to inhabit and remarkable to look upon, in the manner of the very best of our historic cities? Private development would follow, but the first work is the task of the state.