For all their virtues, the inter-war suburbs need to change
How can we modernise the suburbs, increase the number and variety of homes and reduce car dependence – but maintain the space, greenery and independence that people value?
This report shows how urban intensification of suburban London can increase housing supply, promote economic activity, improve local service provision and reduce congestion – whilst improving the quality of life, the choices available and the sustainability of the suburbs. Doubling the density of just 10% of the outer London Boroughs could create one million new homes.
Supurbia is a strategy for intensifying London’s suburbs that balances their inherent advantages with higher density and amenity value. Its approach is twofold: redeveloping the local main streets and parades as mixed-use places with increased housing, improved service and amenity provision; and enabling owner-occupiers to develop their land, creating rich diversities of housing. The strategy will bring together local authorities and communities to plan appropriate developments, and allow homeowners to release equity in their land for home improvements. It will also reduce reliance on mainstream developers to ease the housing crisis, providing an approach that is more adaptable to communities’ needs.
Permitted development rights can incentivise suburban householders to collaborate in replacing and supplementing their houses with modern homes. Giving suburban householders a vested interest in development could help to overcome resistance to change. There are over 725,000 semi-detached and detached houses in the outer London Boroughs. This scheme could create over 100,000 additional homes and renew a similar number.
16 Ideas for transforming Metroland
The original report Supurbia: a study in urban intensification in Outer London was produced by HTA Design LLP in 2014.
It asked: how might suburban transformation be triggered, what incentives might begin to unlock the potential? Is there a case for special measures based on the principle of Housing Zones proposed in the GLA’s Housing Strategy? Or should the incentives be more generally applied across the outer Boroughs and London as a whole? The study made 16 preliminary proposals for further discussion. Many of these have been developed further in this latest report and in submissions to the NLA’s New Ideas for London Insight Study.
Creating value in suburbia
The place potential of well connected areas of metroland makes possible value uplift associated with the Supurbia vision. According to Savills, the gross development value generated by homeowners who club together to develop their plots could be as much as 60% - a considerable incentive for change.
The Metroland problem
When London’s Metroland was first developed in the early 20th century, it was conceived as an affordable means of access to London’s booming economy for working Londoners. It was popular, successful and gave rise to a culture all of its own, perhaps best characterised by the late British poet laureate, Sir John Betjeman in his 1973 documentary film, Metro-Land, made for BBC, and in various evocative poems, including ‘Middlesex’; ‘Gaily into Ruislip gardens / runs the red electric train...’
A century later, perceptions of some areas of outer London have deteriorated and some suburbs are under-performing by comparison with central London, lagging behind in job creation, average incomes and property values. According to the Smith Institute ‘Towards a Suburban Renaissance’ levels of poverty were still growing in outer London suburbs in 2014, whilst remaining stable in central London during the same period.
Supurbia is an idea that recognises that the capacity to increase supply identified in the recent Strategic Housing Land Availability Assessment (SHLAA) for London already includes the contribution of all currently identified brownfield sites, infill sites, redeveloped local authority stock and redeveloped industrial land. So the Supurbia idea instead concentrates on the capacity of the three quarters of a million privately owned semi-detached houses in outer London. Whilst once the suburban ideal, there has been some loss of original character, as front gardens have been converted for parking and verges and trees lost to hardstanding. Moreover, changes in household makeup mean that ever fewer households really benefit from their space.
These homes are not only low density - typically averaging only 25 - 35 homes per hectare - but amongst the most under-occupied. Nearly 40% of owner-occupier households (often ‘empty nesters’) have at least two spare bedrooms, while sharing groups who increasingly rent suburban homes rarely take full advantage of large gardens. In Bexley, based on the 2011 Census data, 45% of the population inhabit the ubiquitous three bed semi. 60% of the households comprise two persons or less, 80% are owner occupiers, 66% own cars, 24% own two or more cars. In one neighbourhood of three and four bedroom semis in Bexleyheath, which we examined as a pilot, we estimated that 38 households comprised 110 people including only 18 children, or 2.9 people per 3- or 4-bedroomed home.
At the same time, occupants of the suburbs are famously resistant to changes that might unlock the vast potential of this huge area of low density city. According to The Centre for London, 75% of people in outer London Boroughs (compared to 50% in inner London) oppose new housing development in their neighbourhoods. The politics and planning of housing development now favour the rights of those who are well housed to resist development in their neighbourhoods to meet the needs of those who are not. This phenomenon is now evident in all sectors of society, not just amongst the well-resourced middle classes.
The Supurbia project examines how financial self-interest could be one way of stimulating change and delivering new housing development. The potential prize is great: doubling the density of just 10% of the outer London Boroughs would create the capacity for one million new homes - the area covered is simply huge and the capacity so correspondingly great that it should not be overlooked, either by the Local Authorities concerned or by the Mayor of London, who seek to find solutions to London’s housing crisis.
But how might such changes be triggered and what incentives might begin to unlock the potential? And is there a case for targeted measures based on the principle of Housing Zones proposed in the GLA’s Housing Strategy, or should the incentives be more generally applied across the outer Boroughs and London as a whole?
The objective of Supurbia is to build on the inherent quality of the suburbs (individual homes on their own plots with parking, easy access to public and private open space set in a verdant environment) with a set of policies targeted at meeting popular aspirations. The underlying premise is that by offering people choices that are currently denied them, a notoriously static situation might be transformed into a dynamic one. A programme of urban intensification might trigger changes resulting in a much improved fit of population to its accommodation; that is more sustainable, efficient, affordable and desirable. The intended outcome is both an increase in housing supply and a more visually pleasing, greener urban environment. This should come alongside an improvement in economic activity, local service provision and reduction in energy use and congestion. In all, an improved quality of life for London’s suburbanites.
Some of the neighbourhoods we have examined as potential pilot areas are decidedly sub-topian examples of a paradise lost; once tree-lined streets are now tree-less, what were front gardens are now concreted driveways, and homes have such low rates of occupancy that local services struggle and trade dies in local parades awash with cheap take-away joints and pound shops.
The Supurbia idea sets out to re-imagine such neighbourhoods with greater population density, better fitted to the available accommodation and creating improved commercial footfall for improved local services and safer streets. Our calculations show how contemporary building and public realm design, and standards of construction can also dramatically reduce energy use and increase biodiversity. Similarly, techniques of neighbourhood infrastructure design and management can redistribute supply and demand to avoid the necessity of major infrastructure replacement and renewal.