Some people may question why, in a world of diminishing resources, we should plan for growth. But the lessons from history, and from across the world, tell us that cities that aren’t growing are declining.

Manchester is a city that has experienced such decline. In the decades up to the 1990s it lost people and jobs and the city suffered economically and environmentally. In the last twenty years, this has been turned around dramatically as Manchester has led the way amongst the UK’s provincial cities in re-growing its population and its economy.

But growth brings challenges too. We need to decouple growth from resource consumption and carbon emissions and this needs to affect both where and how we build.  

There are many who would argue that a city that lost almost half of its population in the last century should be able to grow within the bounds of its urban area, without spilling onto green fields.

URBED has explored this issue in Sheffield and has come to the conclusion that up to 70% of the housing that we need can indeed be built within the urban area. This however is not easy. Vacant brownfield land accounts for perhaps a third of urban capacity, while much of the land once occupied by terraced housing has since been developed for employment, turned over to urban green space, or developed for much lower density housing. Bringing it forward for new housing will take time and money.

There is therefore a strong case for looking at the development of some of the new housing that Greater Manchester needs on its green belt. This does not mean encouraging urban sprawl, but rather promoting sustainable, well-connected new neighbourhoods - a concept summed up in the idea of the Garden City.

In 2014 URBED won the Wolfson Economics Prize for an essay which argued that Garden Cities should not be built as free standing new towns but as extensions to existing cities. We showed how we might build walkable garden city suburbs connected by public transport to established city centres making use of all of the infrastructure that already exists in these places.

This was as much an economic model as a physical one and the essay described a process to harness the uplift in land values on green field sites to invest in new infrastructure, country parks and indeed to help fund urban sites. In this way the whole of the city becomes a Garden City through a process of planned sustainable growth.

So lets imagine a series of Garden City Suburbs around Manchester where a wide range of people can live in (and even build their own) sustainable homes in new green neighbourhoods.

Places within walking distance of everything you need locally and no more than twenty minutes by public transport or bike from a major town centre or the city centre.

Lets also imagine a series of Sustainable Urban Neighbourhoods, or Urban Villages within the urban parts of the conurbation where higher density, sustainable housing regenerate existing communities.

And lets imagine a system by which urban villages and garden suburbs are carefully masterplanned and built to a range of quality and sustainability standards. This is the type of bold planning that took place in Manchester and other cities after the war, but has since fallen out of fashion - proper planning to create a strong vision for the whole of Greater Manchester.