GIS and Evidence-Based Policy Making - Chapter 9 pot

9 Residential Property Utilization: Monitoring the Government Intensification Agenda Peter Bibby CONTENTS 9.1 Introduction 177 9.1.1 Policy, Evidence, and GIS 178 9.2 Patterns of New Construction: Accommodating Housebuilding within Urban Areas 181 9.3 Accommodating Housebuilding: Urban Areas and Beyond 185 9.4 Using Grids to Characterize Dispersal of Housebuilding 191 9.5 Using Grids to Explore Structural Effects and Market Relations 194 9.6 Within the Urban Areas: Intensification of Units of Occupation 1998—Reconstructing a Grid Using PAF 214 9.7 Within the Urban Areas: Intensification of Utilization of Existing Property 217 9.8 Constructing a Fine-Grained Settlement Geography to Identify Development Contexts 220 9.9 Conclusions 229 9.9.1 Development Patterns and Policy Objectives 230 9.9.2 Methods and Representations 230 9.9.3 Relation between Policy, Evidence, and GIS 233 References 235 9.1 Introduction The Government is committed to promoting more sustainable patterns of development, by: . concentrating most additional housing development within urban areas; . making more efficient use of land by maximising thereuseofpreviously developed land and the conversion and reuse of existing buildings; ß 2007 by Taylor & Francis Group, LLC. . assessing the capacity of urban areas to accommodate more housing; . adopting a sequential approach to the allocation of land for housing development; . managing the release of housing land; and . reviewing existing allocations of housing land in plans, and planning permissions when they come up for renewal. (Department of Environment, Transport and the Regions; DETR, 2000c, para 21) It seems peculiar to her suddenly that they should be living in this space: a hundred years ago it would have been a garment factory, where immigrants from eastern Europe stitched fabric into human shapes and practised getting their tongues around the muted diphthongs of English. This is what Lily loves about London, that every building, street, common and square has had different uses, that everything was once something else, that the present is only the past amended. (Maggie O’Farrell, My Lover’s Lover, London, Review 2002, p. 41) 9.1.1 Policy, Evidence, and GIS In the opening years of the twenty-first century, planning policy in England and Wales was clearly directed to conserving un developed land and to the intensification of use of urban areas. DETR’s Planning Policy Guidance Note 3 of 2000 (PPG3) encapsulated this emphasis. The term intensification denotes ‘‘a combination of changes in built form and activity’’ and focuses attention on the capacity of urban areas both to accommodate extra dwell- ings and to adapt to new economic roles. At the microscale, the term implies development of previously undeveloped pores within cities; the redeve- lopment of existing buildings and previously developed sites at higher densities; and the subdivision, conversion, and extensio n of existing build- ings. All contribute to the intensification of use of existing buildings or sites and changes of use allowing increases in the numbers of people living in, or working in an area (Williams, 1999, p. 168). Policy has focused on amending the past in a manner which provides for more sustainable development and which celebrates—perhaps in the manner of O’Farrells’s Lily—the values of urban living. Over the same period, across government, there was a reinvigorated interest in founding policy upon evidence. It therefore seems plausible that there might be some potential role for GIS (and indeed for Geographic Information Science (GISc)) in developing and monitoring policy for reshaping of the physical environment. This chapter explores some of that potential. Its focus is on monitoring urban growth and the conservation of undeveloped land, on monitor- ing the media ting influence of urban land recycling, and on the reuse of existing buildings. It attempts to contribute to debate at three levels. Most immediately, it attempts to use GIS to draw some inferences about development patterns in England and Wales which might be pertinent to ß 2007 by Taylor & Francis Group, LLC. the assessm ent of policy. Second, it considers how particular techniques, including the use of natural language processing (NLP) with GIS, can contribute to the exploitation of data for policy purposes. Third and most fundamentally, it is concerned with the overall relationship between policy, evidence, and GIS and with the manner in which GIS use is and might be embedded within policy pro cesses. A prerequisite of addressing the first of these concerns is a broad under- standing of aspects of relevant government policy in 2000 and immediately afterwards, while engagement with the third concern demands some explicit consideration of how the term policy itself is to be un derstood. The emphases of the 2000 revision of PPG3 reflect a commitment to regeneration and intensification, which suffuses popular planning thought and rests in turn on underlying concerns about sustainable urban living and broader notions of environmental sustainability. The 2000 revision of PPG3 must, therefore, be understood alongside a welter of other documents (including, for example, the urban and rural white papers of DETR, 2000a,b) and Prescott’s (2003) statement on sustainable communities which depend upon the broader discourse of sustainable development. It must be emphasized, how- ever, that other discursive currents influence present policy set out in the Communities and Local Government’s Planning Policy Statement 3 (PPS3; CLG, 2006). CLG is the successor department to the Office of the Deputy Prime Minister (ODPM), DETR, Dep artment of Transport, Local Government and the Regions (DTLR), and the Department of Environment (DoE). The concept of policy pertinent to this chapter should neither be reduced to the text of PPG3 (or PPS3) nor bloated to include the sum of concerns about sustainability. In the traditi on of Heclo, policy might be regarded as a ‘‘course of action or inaction’’ (Heclo, 1972, p. 85). The policy process might thus be seen as centering on the articulatio n of commitments intended to guide subsequent action. From this perspective, the prime significance of texts such as PPG3 is that they potentially allow such commitments to bind actors such as local authority planners who may be distant from central government policy making both in space and time. The policy process involves ensuring such attenuation, so that policy becomes a ‘‘stance which once articulated, contributes to the context within which a succession of future decisions will be made’’ (Hill, 1997, p. 7 ascribed to Friend et al., 1974, p. 40). The context reproduced by the policy process is sometimes referred to as the policy setting and includes an assumptive world of values, metaphors, and core narratives reflected in bureaucratic practices, operational definitions, and procedural rules. Evidence is always used to support or supplant a story. Policy rests upon particular understandings of the nature of the world. Given the nature of policy, its relation to evidence is less straightforward than might first appear. Context denies the possibility of transparent empiricism, thereby complicating the role of GIS in monitoring its effectiveness. Sustainability, moreover, should perhaps be seen as an ‘‘essentially contested ’’ concept in the spirit of Gallie (1955–1956). Without elaboration of a particular narrative, ß 2007 by Taylor & Francis Group, LLC. and of particular definitions, GIS, however useful, cannot provide a tool for distinguishing sustainabl e and unsustainable patterns of development. It, therefore, cannot somehow ground policy in evidence in an unproblematic manner. The evidence assembled using GIS is constrained by the data which it has been deemed worthw hile collecting and framed by particular narra- tives and images within the policy setting. Understanding the potential of using GIS in policy monitoring involves appreciating the character of the traditional narratives. One such narrative provides an account of urbanization which focuses on the construction of dwellings, leading from the idea of exogenous household growth to expan- sion of the contiguous urban area and concomitant reduction in undeveloped land. The number of dwellings in Great Britain has increased by 80% in the last 50 years (Matheson and Babb, 2002, p. 163). The traditional narrative has moved with images such as ‘‘a Bristol a year,’’ directly from increasing numbers of households to the expansion of the contiguous urban area, and this provides the imagery by which the press expresses the environmental consequences of household growth [see, for example, the transmutation of forecast changes in numbers of households into ‘‘twenty-seven huge new towns’’ (Daily Telegraph, 1996) or the invocation of ‘‘an area the size of Manchester’’ (Observer, 2003)]. They converge with images of urban growth, urban sprawl, and urban spread, which liken cities to organisms, demanding responses such as CPRE’s Sprawl Patrol. Such images are reflected and sup- ported by famil iar cartographic devices, which record the expansion of particular towns over time, which may be replicated within GIS. More recent narratives, however, qualify this story. Growth in numbers of households remains at the core. Although population growth has been modest in recent years, household growth—and hence urban growth—has continued (sustained by rising real incomes). This growth is to be understood in relation to changing lifestyle choices that show themselves statistically as continuing falls in average household size. Variants of the narrative typically question how new households or dwellings are to be accommodated, but not the sustainability of those social choices that allow household size to continue to fall (DoE, 1996). Through the 1990s policy discussion became increasingly concerned with the extent to which development might be concentrated on brownfield sites and hence mitigate pressure for urban expansion. This in turn prompted GIS development including both small-scale analytic work under- pinning urbanization forecasts (Bibby and Shepherd, 1996) and development of a National Land Use Database (NLUD)—an inventory of brownfield sites. In the absence of strong popul ation growth, by 2000, household growth had come to coexist alongside crude housing surplus at national level (Matheson and Babb, 2002, p. 164). In particular cities and regions, problems of low demand for housing had come to assume prominence (e.g., Bramley et al., 2000) and these issues had risen high up the policy agenda. Narratives of urban growth thus came to interact with rather different narra- tives of local housing market collapse. These emphasized the rapid, extreme, and essentially arbitrary nature of local market adjustment as withdrawal of key actors (such as particular social landlords), vandalism against empty ß 2007 by Taylor & Francis Group, LLC. property, and outbreaks of social disorder might undermine the possibility of continued occupation. The specter of urban expansi on running apace along- side the dereliction of redundant urban quarters had become evident. Policy, moreover, must be concerned not only with substantive goals but also to the manner in which they are to be pursued. In a climate where evidence is used to legitimize policy, where there is a lack of confidence in forecasts, and where there is uncertainty over the performance of local housing markets, monitoring came and remains to the fore (in principle at least). The 2000 revision of PPG3 introduced a ‘‘plan, monitor, and manage’’ approach to planning for housing in preference to the previous regime— somewhat disparagingly dubbed ‘‘predict and provide’’ retrospectively (Prescott, 2000). This provides the context in which this particular series of GIS applications is set. It is very different to one in which housing demand—driven by population growth—would inevitably be met by the construction of family housing immediately recognizable by remote sensing and easily represented on large-scale maps. 9.2 Patterns of New Construction: Accommodating Housebuilding within Urban Areas The introductory quotation from the 2000 revision of PPG3 (DETR, 2000c) focuses on three objectives: concentrating housebuilding on sites within urban areas, concentrating housebuilding on previously developed sites, and accommodating new dwellings within existing buildings. The remain- der of this chapter treats each of these objectives in turn, using GIS to explore how far patterns of housebuilding in the 1990s proved consistent with the intentions set out in 2000 and exploring some of the issues arising. In so doing it must have regard to the closely linked intentions to avoid developments which make inefficient use of land (those of less than 30 dwellings per hectare net) encourage housing development which makes more efficient use of land (between 30 and 50 dwellings per hectare net) and seek greater intensity of development at places with good public trans- port accessibility . . . such as city, town, district and local centres or around major nodes along good quality public transport corridors. (PPG3; DETR, 2000c, para 58) The location of new development in relation to existing urban areas would appear to be an issue where there is a clear role for GIS and where the analytic issues are trivial. Effective monitoring might appear to depend simply on the availability of information on the location of new housing sites on the one hand and the boundaries of urban areas on the other recorded with sufficient ß 2007 by Taylor & Francis Group, LLC. pre cision and accura cy. Fortunately, Ordnance Survey (OS)—the national mapping agency—generate both sets of data. Since 1985 they have collected Land Use Change Statistics (LUCS) for what is now CLG as an adjunct to updating the national map base (Sellwood, 1987). This constitutes a tractable source of very fine-grained information about the location of new housebuild- ing (among other things). OS have also produced for CLG and its predecessors highly detailed boundaries of physical urban areas for use alongside Census statistics for 1981, 1991, and 2001 (for a discussion of these boundaries and their relation to other urban definitions, see Shepherd et al., 2002). LUC S data re fer to the land par cels shown on ba sic-scale maps (1:125 0 in urban areas 1:2500 at the urban fring e and 1:1 0,000 in mo untain and mo orland areas ). Whe re the use of any suc h parcel changes (on the bas is of a 24-categ ory classific ation) a LUC S record is create d. It will incl ude a 10-m gri d referen ce for a rep resentat ive poi nt with in the parcel , a one charact er code (e.g ., R for residen tial) indicati ng the use befo re and anoth er ind icating the use after the change , an estim ate of the year of change, an estimate of the area of the site, and (in the case of residential development) an estimate of the number of dwellings demolished and the numbe r of uni ts buil t. As shown in Tab le 9.1, these da ta ind icate that in the years from 1990 to 2000 (inclusive), 1.45 million houses were built in Eng- land on 586 square kilometers of land (i.e., at an average density of 24.7 units to the hectare). It is important to note at the outset that the implied annual rate is historically low, although the scale of development is of the same order of magnitude as that required to meet household projections (e.g., DoE, 1995) or that suggested by the Barker (2004) review. Digital boundaries of physical urban areas are generated for CLG by OS on the basis of a series of rules. The rules are used to aggregate parcels on the basis of their use and the distance between them. Any parcel on a basic- scale map is treated as being in either urban or rural use. The classification used is the same as that in LUCS, the individual uses being arranged into these two divisions. Parcels in urban use are then joined with their neigh- bors or other such parcels within 50 m to form areas of urban land. Open land totally surrounded by an area of urban land (such as Hampstead Heath or Richmond Park in London, or Sutton Park in Birmingham) is also treated as forming part of it. (Under the 1991 definition, a subset of these areas of urban land are deemed to be urban areas.) Simply overlaying LUCS point data on the OS 1991 urban area polygons reveals that over the 1990s, in the order of 57% of new dwellings were accommodated within those urban areas (Table 9.1).* Although * In the case of the boundaries produced by OS for use with the 1991 census, a distinction was made between areas of urban land and urban areas. An urban area for this purpose was defined as an area of urban land that impinged on four or more enumeration districts (the smallest units for which 1991 census data were released). This implied a variable lower limit to the population of urban areas (between 1000 and 2000 persons). The boundaries produced for the 2001 census encompassed a far larger group of settlements. For this study the term urban areas refers to physical settlements treated as urban areas in 1991 and with a 1991 population of 2000 or more. ß 2007 by Taylor & Francis Group, LLC. TABLE 9.1 New Dwellings Built and Housing Land Developed, 1990–2000, England: Urban Areas (UAs) and Elsewhere Outside UAs Inside UAs Totals % Inside UAs Year Units Hectares Density Units Hectares Density Units Hectares Density Units Land 1990 51,516 3,337.9 15.4 110,046 3,841.0 28.7 161,562 7,178.9 22.5 68.1 53.5 1991 43,846 2,110.9 20.8 79,643 2,543.3 31.3 123,489 4,654.2 26.5 64.5 54.6 1992 52,126 2,582.8 20.2 78,714 2,626.8 30.0 130,840 5,209.6 25.1 60.2 50.4 1993 59,919 2,886.0 20.8 83,875 2,702.1 31.0 143,794 5,588.1 25.7 58.3 48.4 1994 70,735 3,500.0 20.2 81,493 2,772.4 29.4 152,228 6,272.4 24.3 53.5 44.2 1995 61,403 3,194.4 19.2 76,938 2,589.3 29.7 138,341 5,783.7 23.9 55.6 44.8 1996 61,967 3,029.5 20.5 66,095 2,101.5 31.5 128,062 5,130.9 25.0 51.6 41.0 1997 66,924 3,284.6 20.4 74,027 2,345.9 31.6 140,951 5,630.5 25.0 52.5 41.7 1998 65,839 3,118.9 21.1 69,252 2,239.3 30.9 135,091 5,358.2 25.2 51.3 41.8 1999 48,189 2,390.7 20.2 55,083 1,781.7 30.9 103,272 4,172.4 24.8 53.3 42.7 2000 45,100 2,124.3 21.2 45,703 1,533.9 29.8 90,803 3,658.2 24.8 50.3 41.9 Total(1) 627,564 H(RU1) 31,559.84 L(RU1) 19.9 820,869 H(UA1) 27,077.3 L(UA1) 30.3 1,448,433 58,637.1 24.7 56.7 46.2 Total(2) 570,784 H(RU2) 28,433.4 L(RU2) 20.1 877,401 H(UA2) 30,194.89 L(UA2) 29.1 1,448,185 58,628.3 24.7 60.6 51.5 Total(3) 564,516.3 H(RU3) 28,128.4 L(RU3) 20.1 883,773.7 H(UA3) 30,503.5 L(UA3) 29.0 1,448,290 58,631.9 24.7 61.0 52.0 2004 Definitions Total(4) 698,284 H(RU4) 34,752 L(RU4) 20.1 750,005.9 H(UA4) 23,880.2 L(UA4) 31.4 1,448,290 58,631.9 24.7 51.8 40.7 Note: The year-by-year values and Total(1) values have been calculated by treating LUCS data as points and overlaying them on urban area polygons. The values for Total(2) have been obtained by treating LUCS data as points and overlaying them on a 100-m grid derived from the urban area polygons. The values for Total(3) have been obtained by spreading LUCS data across a 100-m grid as described in Section 9.4 and overlaying the derived values on a 100- m grid derived from the urban area polygons. ß 2007 by Taylor & Francis Group, LLC. there are no quantitative targets for the proportion of housebuilding to be accommodated within existing urban areas, it appears that these areas were able to absorb well in excess of 800,000 new dwellings in the period. The table appears to provide a substantial degree of comfort to those anxious to realize the government’s goal of ensuring that by 2008, 60% of new housebuilding is accommodated on previously developed sites. (Note that this table says nothing about previously developed sites per se.) Those practitioners and commentators who remain profoundly skeptical of the realism of such targets might also find within Table 9.1 some justifi- cation for their position. They might question how long this pattern of development might be sustained, pointing out that while more than two- thirds (68%) of new dwellings appear to have been accommodated in urban areas in 1990, this proportion fell steadily through the decade, so that only half of all new dwellings were being accommodated in this way by 2000 (Figure 9.1). Moreover, it appears that less than half of all house- building land was found within the confines of urban areas as they had stood in 1991, and that this proportion too followed a distinct downward trend. This is consistent with the familiar view that with the passage of time it becomes progressively more difficult to identify sites within the urban area. Accommodating housing with urban areas LUCS 1990–2000 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 Percent % Units % Land Housing output recorded in LUCS 1990–2000 0 20,000 40,000 60,000 80,000 100,000 120,000 140,000 160,000 180,000 1990 1998 2000199619941992 1990 1998 2000199619941992 Units in UAs Total FIGURE 9.1 Housebuilding within urban areas in England between 1990 and 2000. (From LUCS. With permission.) ß 2007 by Taylor & Francis Group, LLC. Unravel ing these mixed me ssages and draw ing out their im plication s demands a mo re thorough examin ation of the evidenc e, questio ning the usual nar ratives more closel y, and depl oying GIS more creativel y. Table 9.1 moves only a tiny step towards understanding how new dwellings have been accommodated or the extent to which they might be accomm odated in urban areas in the future. The rest of this chapter attempts to move succes- sively closer to definitions that are substantively meaningful in policy terms. This first definition of urban areas will be called UA1. The number of dwellings accommodated within the 1991 urban areas will be referred to as H(UA1), and the corresponding area of land developed L(UA1). Subse- quent definitions of urban areas will be referred to as UA2 and so on, the general case being termed UAi (and the corresponding rural residual RUi). Development within UAi will be referred to here as urban consolidation (accommodating additional households within existing urban areas through either infilling of green pores or recycling of previously developed sites). In the 1990s, debate counterposed such urban consolidation against rural land conversion in the form of either urban extensions (UXi)orof new settlements (NSi) (e.g., Breheny et al., 1993). It is, of course, usually assumed that demand can be diverted between these different contexts and so it is impossible to understand the volume of new dwellings being accommodated in cities in isolation. As a next step we attempt to partition the total number of dwellings built over the 1990s, H(TO), into these components. 9.3 Accommodating Housebuilding: Urban Areas and Beyond As the very idea of urban extensions embodies the metaphor of the city as polygon, elementary GIS operations should in principle allow for their direct measurement and for examination of their contri bution to the housing land supply. Urban extension polygons might be defined as a subset of the difference polygons created by overlaying the urban area polygons defined by OS for use with the 2001 census with those for 1991 (defining UX1). New settlements (NS1) might be represented by urban area polygons not present in 1991 but found in 2001. Urban consolidation would occur in the polygons forming the intersection of the two sets (UA1). This simple geometric logic demands the recognition of two further types of circumstance which are more marginal to policy discourse. The first is represented by difference polygons referring to land considered urban in 1991 but not in 2001. These might be thought of as urban contraction polygons. The second comprises an outside remaining rural throughout also represented by a polygon (or in principle more than one). This last class of circumstance thus constitutes what might be termed as an exurban context (specifically XC1). The number ß 2007 by Taylor & Francis Group, LLC. of new dwellings accommodated in eac h of these contexts might in principle be assessed by overlaying LUCS point data on the polygons defined. Thus H(TO) ¼ H(UAi) þ H(RUi) or H(TO) ¼ H(UAi) þ H(UXi) þ H(NSi) þ H(XCi) and specifically H(TO) ¼ H(UA1) þ H(UX1) þ H(NS1) þ H(XC1): Alfreton Sutton Kirkby Pinxton Mansfield Urban areas 1991 Urban areas 2001 Selston c c c x x Z Z Inset 1 km 3 km Ravenshead c d e FIGURE 9.2 Urban area polygons in 1991 and 2001. Detail from part of the Nottinghamshire Coalfield. Note: Because of the procedural rules used to define urban area polygons (see text), they are very convoluted. Comparison of polygons for 1991 with those for 2001 provides a clear indication of urban expansion (see for example areas of expansion such as those marked ‘‘X’’ on the western fringe of Ravenshead. Although they are not consistent with the notion that changes to urban use are fundamentally irreversible, areas of urban contraction are also found (such as those marked ‘‘c’’ above). While some of these appear to reflect change on the ground, other change appears to reflect differences of view. This seems particularly clear in the inset which shows the south-western limit of Sutton-in-Ashfield. Here differences in the western settlement margin appear to reflect a digitzing decision, and the minor contraction along the southern limit an arbitrary decision that in 1991 the A38 dual carriageway should be included within the urban area although it was excluded in 2001. The apparent contraction (c) seems to reflect a change of view, whereas the expansion (d) seems consistent with change on the ground, though the apparent contraction (e) seems to arise from another change of view. ß 2007 by Taylor & Francis Group, LLC. [...]... Mode of Accommodation Units Built, 199 1–2000 Outside UAs 2001 Outside UAs 199 1 Inside UAs 199 1 Total Percentages Outside UAs 199 1 Inside UAs 199 1 Total 205,505 5,256 210,761 14.2 0.4 14.6 Inside UAs 2001 422,0 59 815,613 1,237,672 Land Developed, 199 0–2000 Total 627,564 820,8 69 1,448,433 29. 1 56.3 85.4 43.3 56.7 100.0 Units Built 199 0–2000 Exurban development Reclassification Urban extension Urban consolidation... 422,0 59 815,613 1,448,433 205,505 422,0 59 820,8 69 1,448,433 14.2 29. 1 56.7 Outside UAs 2001 Inside UAs 2001 Total Outside UAs 2001 Inside UAs 2001 Total 14,248.67 261.16 14,5 09. 83 17,311.17 26,816.13 44,127.3 31,5 59. 84 27,077. 29 58,637.13 14.4 20.1 21.6 24.4 30.4 25.7 19. 9 30.3 24.7 24.3 0.4 24.7 29. 5 45.7 75.3 53.8 46.2 100.0 Land Developed 199 0–2000 14.2 0.4 29. 1 56.3 100.0 Densities Achieved, 199 0–2000... intensification Densities Achieved 199 0–2000 14,248.67 261.16 17,311.17 26,816.13 XC1 UX1 UA1 24.3 0.4 29. 5 45.7 100.0 14.4 20.1 24.4 30.4 14,248.7 17,311.2 27,077.3 58,637.2 24.3 29. 5 46.2 100.0 14.4 24.4 30.3 (continued ) ß 2007 by Taylor & Francis Group, LLC TABLE 9. 2 (continued ) New Dwellings Built and Housing Land Developed, 199 0–2000, England: by Mode of Accommodation Units Built, 199 1–2000 Outside UAs 2001... Overall 170 ,91 0 399 ,874 877,401 1,448,185 11.8 27.6 60.6 100.0 Totals(3) Exurban development Urban extension Urban consolidation Overall 185,628 378,888 883,774 1,448, 290 2004 Rural Definition Exurban development Urban extension Urban consolidation Overall 398 ,165 300,120 750,006 1,448, 291 Land Developed, 199 0–2000 Densities Achieved, 199 0–2000 Outside UAs 2001 Inside UAs 2001 XC2 UX2 UA2 11,7 89. 8 16,643.6... the stock of urban land within 10 km Second it posits a price effect Figure 9. 10 clearly confirms the structural effect There is a very close relationship at the 10-km scale between the extent of urban land in 199 1 [i.e., G(UA3(q,10000))] and the area of urban land developed for housing in the 199 0s [S(L(UA3 (q,10000)))], accounting for 91 .3% of the variability of the latter (Figure 9. 10) Generally, therefore,... 11,7 89. 8 16,643.6 30, 194 .8 58,628.2 20.1 28.4 51.5 100.0 14.5 24.0 29. 1 24.7 12.8 26.2 61.0 100.0 XC3 UX3 UA3 12, 597 .9 15,530.5 30,503.5 58,631 .9 21.5 26.5 52.0 100.0 14.7 24.4 29. 0 24.7 27.5 20.7 51.8 100.0 XC4 UX4 UA4 22 ,94 9.6 11,802.1 23,880.2 58,631 .9 39. 1 20.1 40.7 100.0 17.3 25.4 31.4 24.7 Total Total Outside UAs 2001 Inside UAs 2001 Total Note: The crosstabulated values and Total(1) values have... 0.0001845 + 0.02349x r 2 = 0 .91 28 0–0.2 0.2–0.8 >0.8 FIGURE 9. 10 Urban residential land supply, 199 9–2000 (ha=km2) < −0.1 −0.1 to 0.1 > 0.1 show very little systematic variation apart from a distinction between Central London and elsewhere For present purposes, two further estimates of residential land price consistent with 10 KRM were prepared, both using the principle of residual-land valuation Residual... (iii) That the demand for additional housing units is price and income inelastic, but that the demand for housing space per unit decreases with its price per square meter and increases with income (iv) That the supply of urban land for housing is a function of the stock of urban land and increases with the price of land (v) That the supply of rural land is a function of the stock of land free of planning... West Midlands), Dunkeswell near Honiton in Devon, Southfields in Essex Thameside (Thurrock), and Tanfield (a village abutting the urban area of Cheshunt in the Hertsmere District of Hertfordshire) ß 2007 by Taylor & Francis Group, LLC ß 2007 by Taylor & Francis Group, LLC TABLE 9. 2 New Dwellings Built and Housing Land Developed, 199 0–2000, England: by Mode of Accommodation Units Built, 199 1–2000 Outside... the remainder of the analyses in this chapter Converting the 199 1 and 2001 urban areas to hectare grid representations forms the basis for a revised definition of contexts UA2, UX2, XC2 allowing identification of urban consolidation, urban extension, and exurban development, respectively Tables 9. 1 and 9. 2 therefore also show alongside estimates made on a point-in-polygon basis (UA1, UX1, etc.) variant . 199 0–2000 0 20,000 40,000 60,000 80,000 100,000 120,000 140,000 160,000 180,000 199 0 199 8 2000 199 6 199 4 199 2 199 0 199 8 2000 199 6 199 4 199 2 Units in UAs Total FIGURE 9. 1 Housebuilding within urban areas in England between 199 0 and 2000. (From LUCS. With permission.) ß. 3, 194 .4 19. 2 76 ,93 8 2,5 89. 3 29. 7 138,341 5,783.7 23 .9 55.6 44.8 199 6 61 ,96 7 3,0 29. 5 20.5 66, 095 2,101.5 31.5 128,062 5,130 .9 25.0 51.6 41.0 199 7 66 ,92 4 3,284.6 20.4 74,027 2,345 .9 31.6 140 ,95 1 5,630.5. 41.7 199 8 65,8 39 3,118 .9 21.1 69, 252 2,2 39. 3 30 .9 135, 091 5,358.2 25.2 51.3 41.8 199 9 48,1 89 2, 390 .7 20.2 55,083 1,781.7 30 .9 103,272 4,172.4 24.8 53.3 42.7 2000 45,100 2,124.3 21.2 45,703 1,533.9