A debate about the best way to house a growing population

Density

LSE London

London School of Economics

June 2006

This paper provides a brief summary of the key issues raised by the continuing need to find increasing numbers of homes in a relatively congested area of the country and to ensure that these homes help improve sustainability. Many of these issues are not new. The question of how far London should be allowed to grow; whether or not population and employment densities should increase and whether this would reduce the social costs of development; and the need for greater centralisation or decentralisation have been played out in the South East of England for more than half a century. The Green Belt is an important feature of the planning system and has influenced wider debate. Latterly, public policy has deliberately sought to generate an urban ‘renaissance’ on the grounds that this will improve standards of living as well as reduce environmental costs. The terms of the debate are outlined in the following pages.

1. Background

Britain is often described as a densely populated country. 60 million people distributed unevenly around a relatively small geographical area has created a number of policy problems, which have historically been seen in terms of overcrowding within cities and/or their ‘sprawl’ into rural areas. Such difficulties have been complicated by industrial change and also by attitudes to rural, suburban and urban living, involving competing demands for space use. There are major urban concentrations, notably in central Scotland, Yorkshire/Lancashire, the West Midlands and London. However, the fastest population growth over recent decades has occurred in rural areas and small towns, with London being exceptional among the conurbations in experiencing a population turnaround involving significant growth since the late 1980s. The UK population is projected to grow to 65 million by 2023 and 67 million by 2036, with growth continuing until the latest end-date of projections in 2074¹.

However, there are powerful planning and political constraints on the use of green land for new homes. London has been bounded by a Green Belt for over 50 years, though much population and economic activity has jumped over this green zone to places such as Reading, Milton Keynes and Crawley. A strong alliance of forces has combined to defend the countryside and greenfields – not just the formal Green Belt – in effect rationing the amount of land available for new homes. As a result, the planning process has become increasingly contested as the existing residents of rural and semi-rural areas (and their local authorities) have sought to stop the use of virtually all green land for new housing.

More positively, proponents of the ‘compact city’ thesis, including the Urban Task Force, have argued that there are social and economic advantages for the cities themselves, together with global environmental benefits, in reversing the trend to lower urban densities. Higher densities enable better use of transport and urban services and help to reduce the social costs of sprawl. Constraint also helps to ensure effective regeneration of urban areas and so further to reduce the land take. The significance of such effects is strongly contested, however, as is the likelihood that planning policies can of themselves secure such a turnaround. In London, the Mayor has made it a strategic objective since 2002 for projected population growth to be accommodated within Greater London and has set out detailed advice on densities in relation to current uses which, if followed, would generate significantly higher planning densities.

2. Policy proposals

Meeting the forecast numerical demand for homes requires some combination of ‘greenfield’ development, extension/fragmentation of existing dwellings, conversion of non-residential properties, and construction of new dwellings on recycled urban land. Since the 1995 Housing White Paper, central government has set targets for a (higher) proportion of housing development to be accommodated without use of greenfield sites (i.e. through a combination of the other three processes). The so-called ‘brownfield’ target now stands at 60% nationally (remembering that in London the proportion is anyway far above 90%). This approach was reinforced in planning guidance and elsewehere following the original 1999 report of the Urban Task Force, led by Lord (Richard) Rogers. This advocated increased densities within urban areas and higher density standards for new developments as means of encouraging an ‘urban renaissance’. In order to achieve acceptability for such an approach it was argued that a number of other policy changes were required, involving an improved quality of urban life and better architecture.

The present government has strongly supported the idea that new properties should be constructed on brownfield sites and also that planning densities should be increased. Planning policy guidance) has set in place a sequential process which means that brownfield sites will normally take precedence over greenfield sites and identifies higher density standards³. In the capital, the London Plan also embraced these ideas as a way of accommodating a rapid projected increase in the city’s population from 7.4 million today to 8.1 million by 2016. Other organisations such as the Campaign to Protect Rural England have lined up behind similar or even stronger policies⁴.

Not everyone supports raising residential planning densities. There are those who believe that London and other British cities have traditional patterns of settlement that cannot be changed to resemble those of densely-populated European centres. Others argue strongly that whatever the planning densities at the margin the utilisation of the stock will decline with income growth unless other policies, notably those which increase the costs of occupation, are put in place at the same time⁵. The question of how new, densely-built, units of housing could be made affordable – either to buy or to rent – for those on lower incomes will remain, especially as service costs increase with density. Migration is an additional complexity, since while international migrants are seen as happier to embrace ‘European urban living’, existing households can vote with their feet, and recent years have seen a net outflow of some 100,000 per year from London to other parts of (mostly) southern England.

An alternative proposition to the promotion of higher densities within established urban areas would involve relaxing planning restrictions as they apply to – at least some highly accessible – greenfield and green belt land and allow more housing to be built⁶. Sir Peter Hall has suggested that:

“quality of life for Londoners will really begin to suffer if densities get too high – and this would mean a very real risk for house prices if planners and local authorities get this wrong….The draft [London] Plan recognises that something needs to be done urgently to house London’s residents adequately, but cannot do this without the help of neighbouring regions, which will need to accept their share of new homes”⁷.

Recently in a minority statement in the Urban Task Force’s second report, Sir Peter has argued that overachievement of the target to curtail greenfield development is a threat to meeting housing needs⁸, particularly in relation to the significant reductions in rates of house (as distinct from flat) building⁹.

Inevitably, the government has to pursue policies that steer between the enthusiasms of the pro-density/rural-protection lobby, on the one hand, and those who resist suburban-densification and believe that housing needs require a substantial element of greenfield development in new/expanded settlements on the other. The Office of the Deputy Prime Minister (now DCLG) has set targets for new housing units in each region, but these numbers have been fiercely contested by many residents, notably in areas of the Greater South East outside London. They have also set in place not only planning guidance which aims to increase densities but also policies on affordable housing which implicitly favour smaller units built at higher densities across urban areas.

Unless there is a sharp slow-down in the growth of the UK population and economic growth, in particular within the south of England, there will continue to be pressure for more development. Even with little or no population growth, there would be a need for more housing units. As it is, all the evidence suggests the need to prepare for demands for even more homes.

In London and its surrounding regions, this will mean continuing pressure on the planning system. Within the capital, virtually all new units will have to be provided on brownfield land – much of it around the existing city centre and in the Thames Gateway on large sites where higher density, mixed use and mixed tenure development can be implemented. New developments will be built at higher densities than those traditionally associated with suburban London. There will be relatively more flats and fewer houses with gardens.

It is not clear what the public reaction will be to continuing increases in density, both within London and in towns within the South East and East. The number of people living in the capital has risen from 6.7 million in the mid-1980s to 7.4 million today. Densities have been increased. But this growth has also resulted in higher relative prices, a slow down in household formation, and a structural shift in the types of household being accommodated¹⁰. All the signs are that these trends will continue.

But it is almost inconceivable there will not also be irresistible demands for significant numbers of new homes in and around centres elsewhere in the South East and East and that this will also be planned to be at higher densities. Not all green land will be defended.

The Density Debate

There are debates both, on the research front, about the likely consequences of higher densities and more compact urban forms, and on the policy front, about the feasibility and acceptability of raising residential densities to accommodate projected population growth within London, versus alternative strategies for the region.

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  agglomeration has a strong positive effect on productivity levels, though the relevant geographic scale seems to be closer to that of the metropolitan region than of Greater London alone¹¹;
  
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  residential segregation has some effects on social inequality, notably in schooling, but operates more strongly within London than in smaller towns outside¹² ;
  
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  higher planning densities, notably in employment centres, tend to reduce transport emissions by encouraging residents to make shorter trips and more of them by public transport, but the likely effects are very small relative to the scale of reductions required, not least because only occupiers of new developments would be affected¹³; and
  
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  while recycling of brownfield sites in London would reduce the impact on greenfield sites outside the city which are a potential recreational asset for Londoners, it would inevitably restrict their access to more local areas of undeveloped land, which studies of influences on dwelling prices indicate to be much more highly valued¹⁴.
  

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  The London Plan strategy, attempting to accommodate the projected population, household and employment growth entirely within Greater London’s existing urban area, through more intensive use of space in central areas, currently vacant sites and established residential areas. This is clearly an ambitious target in terms of managing development proposals, securing the necessary large scale infrastructure to back these up, exerting effective control over local planning policies/decisions, and influencing the residential preferences of residents who might choose to move out – as well as addressing the resultant affordability problems for key workers and other low income households that must live in London;
  
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  The reverse strategy would be to relax planning constraints on green land within the South East and East, allowing many more people to achieve the traditional ambition of living in homes with gardens. This would involve substantial social, environmental and financial costs as well as benefits and a different set of political obstacles in terms of local resistance to extension of urban areas;
  
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  A more positive/planned alternative to this is to promote more selective forms of, relatively compact, development on greenfield sites outside Greater London – complementing a more modest intensification strategy within London. This might be seen as an extension of the Sustainable Communities programme, at least in the sense that it would involve relatively concentrated patterns if development, rather than the dispersion that simply loosening of controls would be likely to produce, and reasonable densities in locations with efficient public transport access. This too would clearly involve major infrastructure costs (if presumably less than within London) and probably more concentrated opposition in the chosen areas, unless appropriate sweeteners were offered to mitigate negative impacts and costs;
  
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  Such policies could be supported by increasingly relying on taxation and pricing policies to reduce the demand for larger units and more space per household – as well as reducing the incentive to form new households;
  
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  Finally, there is the distinct possibility of a continuing, messy, compromise – presumably not as an explicitly chosen strategy, but because either the London Plan strategy proves unrealistic in practice, or government is unable to formulate and implement a workable alternative.