Density
a debate about the best way to house a growing population
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.
Even where there is no population growth, the number of households has tended to
increase markedly over recent decades and is projected to continue to do so. Figures
published in March 2006 suggested that the number of households in England will
rise from 20.9 million in 2003 to 25.7 million in 2026, equivalent to 209,000 per
annum2. About 60 per cent of the projected growth is in the three interlinked regions
of the Greater South East: i.e. the East of England, the South East and London itself.
London’s total is projected to increase from 3.1 to 3.9 million between 2003 and
2026. The continuing reduction in household sizes has been part of a broader long
term trend for an increasingly affluent population to seek more personal living space
partially offset by increasing prices, especially in London.
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.
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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 socalled ‘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.
3
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.
3.
The future
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.
The research debate involves questions both with respect to the evidence base for
claims that higher densities will promote economic dynamism, reduce social
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segregation/exclusion, and significantly reduce environmental costs notably carbon
emissions from car usage, and the value attached by residents to local open space
within the city, relative to that in areas outside. In the first case recent LSE studies
indicate that:

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;

residential segregation has some effects on social inequality, notably in
schooling, but operates more strongly within London than in smaller towns
outside12 ;

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

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.
The policy debate must necessarily goes beyond these considerations to consider the
strategic alternatives, and the practicalities of implementing different approaches.
The basic choices are between:

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;

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;

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
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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;

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;

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.
Notes
Office for National Statistics Press Notice, 20 October 2005, London: ONS
Department for Communities and Local Government, Statistical Release 2006/0042,
London: DCLG
3
Office of the Deputy Prime Minister, Draft Planning Policy Statement 3: Housing,
London, ODPM, December 2005
4
Campaign to Protect Rural England’s Housing Manifesto, CPRE: London, undated
5
Kate Barker, Delivering Stability: securing our future housing needs, Barker
Review of Housing Supply Final Report, London HM Treasury, March 2004
6
See, for example, Alan Evans and Oliver Hartwich, Unaffordable Housing - Fables
and Myths, London: Policy Exchange, 2005
7
Sir Peter Hall, quoted in Town & Country Planning Association Press Notice
concerning evidence on the London Plan, 3 March 2003
8
Towards a Strong Urban Renaissance, London: Urban Task Force
[http://www.urbantaskforce.org/UTF_final_report.pdf]
9
Peter Hall, ‘Aux armes against housing disaster’, Town and Country Planning 74
(10), October, p288
10
LSE London, London’s Place in the UK Economy 2004, London: Corporation of
London
11
P. Rice and A. Venables ‘Spatial determinants of productivity: analysis for the
regions of Great Britain’ Centre for Economic Policy Research Discussion Paper
4527, 2004: the most relevant area for agglomeration economies is found to be that
within 40 minutes drive-time
12
R. Lupton, ‘How does place affect education?’, in S. Delorenzi (ed) Going Places:
neighbourhood, ethnicity and social mobility, London: Institute of Public Policy
Research, 2006; I.R. Gordon, and V. Monastiriotis, ‘Urban size, spatial segregation
and inequality in educational outcomes’ Urban studies 43, no. 1 (2006), pp. 213-236
13
I.R. Gordon, ‘Densities, urban form and travel behaviour’, Town and Country
Planning, 66, 1997, 239-241
14
P. Cheshire and S. Sheppard, ‘The Welfare Economics of Land Use Planning’,
Journal of Urban Economics, 52(2002), pp 242-269
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