135. While targets are useful in encouraging local
authorities and developers to maximise the use of brownfield sites,
what is achieved will be determined in part by the physical capacity
of areas and by the density of development.
136. Some information is available about the amount
of brownfield land. The Royal Commission on Environmental Pollution
noted that in 1990 there was estimated to be 25,000 ha of vacant
urban land which had previously been developed. It was "more
than the total amount of land which it has been estimated will
be transferred from rural to urban uses during the 1990s".
A detailed survey by DOE in 1993 (the Derelict Land Survey) found
39,000 ha of land in England which was derelict, that was "so
damaged by industrial or other development that it is incapable
of beneficial use without treatment". Half this land was
in urban areas. According to URBED, a survey of vacant land in
urban areas in 1990 identified a figure of 60,000 hectares.
In 1985 DOE estimated that there were at least 10,000 ha of contaminated
land in England, ie. "land which represents an actual or
potential hazard to health or the environment as a result of current
or previous use". While these figures indicate that there
is a very large amount of brownfield land, it is unclear how much
might be appropriately used for housing. Certa (UK) Ltd. told
us "The biggest unknown factor is the scale of the brownfield
land problem in the UK".
137. There is a regional mis-match between the supply
of and demand for brownfield land. It is, however, unclear whether
this is a significant mismatch or whether in most regions a respectable
target for brownfield housing will be achievable.
138. There was disagreement amongst witnesses about
the capacity of brownfield to accommodate housing in the future.
Some witnesses argued that the 'best' and 'easy' sites had already
been developed. In contrast, the Civic Trust stated:
"There are still many
processes of economic and technical change at work in our urban
areas which are likely to result in more redundant sites and buildings,
by no means all foreseeable today. Recent studies however suggest
that we are barely keeping pace with new dereliction and this
in itself probably underestimates actual site vacancy".
In short, "... an analogy is perhaps to consider the scope
for brownfield sites as a 'well' rather than a shallow 'pond'"
139. Tellus 42 undertook research on behalf of Friends
of the Earth into the potential for re-using urban surface car
parks for new housing.
The report found that "the total public and private off-street
car parking ... occupies some 4,600 hectares (1,970 acres)".
However, according to Tellus 42, almost one quarter of this space
is either seldom full or seldom half full. Furthermore the land
would be significantly more valuable if developed: the income
accruing from these car parks "... is likely to be less than
one fifth of the rent from affordable housing or small business
units for the same area".
Various obstacles to the redevelopment of car parks were identified,
including capital receipts legislation which discourages local
authorities from developing Council-owned car parks. However,
the benefits, it was claimed, would include: provision of housing
(an estimated 250,000 households could be accommodated), environmental
improvements, and a reduction in car dependency and urban traffic
140. URBED was commissioned by Friends of the Earth
to test whether the urban capacity existed to accommodate the
UK Round Table's target of 75 per cent of new houses on brownfield
land. Their study collated national data of various forms of housing
capacity in order to arrive at a figure for 'unconstrained' capacity.
The data sources used included the Derelict Land Survey, and estimates
of: the capacity of car parks ("50,000-200,000 homes it is
estimated could be accommodated by redeveloping car parks"),
the scope for converting empty commercial space; the potential
for living over the shop; and the scope for better use of existing
housing (such as subdivision and intensification). URBED found
that it would be possible to accommodate 75 per cent of the housing
growth on brownfield sites, but that it would "... require
widespread changes to both the planning system and the housing
Three sources, it was found, are likely to offer the most significant
potential. These are the redevelopment of brownfield land, living
over the shop and the subdivision of under-occupied larger property.
URBED also highlighted the problem of the geographical mismatch
between supply of brownfield sites and demand for housing:
"It should also be noted
that this analysis does not take account of regional variations
and it is likely that much of the capacity will be in areas where
there is the least household growth."
141. The debate about capacity is hindered by a lack
of research and the absence of a commonly agreed methodology.
However, the work carried out by Llewelyn-Davies on urban capacity
in London and the North West has improved this situation.
The Government, in Planning for the Communities of the Future,
has indicated its support for the approach adopted in these
studies. Llewelyn-Davies presented several case studies to the
Committee which demonstrated that a range of capacities could
be achieved for small gap and infill sites by varying layouts
and density. The consultancy told us:
"We wanted to test the
difference that different approaches to planning, design, density
assumptions might make, both to the scale of site capacity and
to the form and quality of development."
142. The approach is based on five key principles:
viewing brownfield sites as an opportunity and not a threat; relating
housing potential to accessibility to public transport and local
facilities; taking a long term and imaginative view; using a 'design-led'
approach; and adopting a wider 'urban management' approach, for
example considering the use of Neighbourhood Car Fleets.
143. The first case study was taken from a Llewelyn-Davies
study in London, Sustainable Residential Quality, which
looked at the potential for new housing on small sites within
800 metres of London's town centres. Using the example of a single
site, we were shown that density could be increased from six houses,
to 32 units, by
using a design-led approach, making the development car free and
not adhering to standard planning standards on density. In relation
to average site capacities over the whole LPAC study, Llewelyn-Davies
"Aside from quality
benefits, we found that site capacities could be increased, over
that permissible under UDP controls, by about 50 per cent under
Option 2 (a design-led approach) and by about 100 per cent under
Option 3 (design-led approach and car free)."
144. We were also shown examples of sites from a
Llewelyn-Davies North West study where Llewelyn-Davies was commissioned
to draw up a methodology
to guide local authorities in undertaking capacity studies of
their own areas. The Government Office for the North West told
us that pilot studies using this methodology had taken place in
five areas. They
have shown that the region has ample urban capacity and the Government
Office has now urged all local authorities to undertake their
145. While there was widespread support for the more
regular use of urban capacity studies, witnesses pointed out the
problems associated with them. The Local Government Association
was concerned about the "...enormous resources that are required
to undertake these studies"
and highlighted the fact that few local authorities have experience
of carrying out studies.
Guidance was required from the Government as to how to carry them