Is London

1
Is Londons Intensifying Urban Structure Creating
a More Sustainable City?

Duncan Smith 15rd October 2008.

2
Urban Form, Function and Accessibility an
analysis of Londons Intensifying Urban Structure
using 3D GIS

• Why does Urban Form Matter?
• Monocentric and polycentric cities discussion.
• Integrating Geography and Geometry-
• Approaches to measuring urban form and function.
• Density, Accessibility and Urban Development-
• Is Londons intensifying urban form creating a
  more sustainable city?

3
Why Does Urban Form Matter?

• Defining Urban Form
• All physical aspects of the city, its buildings,
  streets, and all other elements that make up the
  urban realm (Talen, 2003).
• A diagram of forces
• (Darcy Thompson, 1917)
• Embedded in Processes Shaping Cities
• Built environment reflection of forces that shape
  cities container where all urban activities take
  place and a major influence on future urban
  developments.
• Geographical research engaging with urban form-
• Economic geography structural economic
  change/globalisation, urban development.
• Social/cultural geography housing and social
  segregation, gentrification, access to services,
  urban quality of life.
• Urban policy and planning.
• Urban Sustainability energy use in buildings and
  transportation.
• All aspects interlinked and cannot be understood
  in isolation

4
Urban Form and Sustainability

• Urban Form Explain Travel Patterns?
• Influential research by Newman and Kenworthy
  (1989).
• Argument from Compact City theory- high density
  mixed use city minimises trip lengths, encourages
  benign modes. Car several times less energy and
  space efficient than public and active transport.
• Compact City Criticisms
• Not geared to process- Urban form evolves with
  the economy, transportation technology,
  socio-cultural trends and planning policy.
  intensification policies not achieving behaviour
  change.
• Loosely defined- how high-density and mixed-use?
  What about variation within cities?
• Ignoring economic realities of 21st century
  cities- polycentric growth. Happening even in
  European cities.

5
Debates in Urban Form and Sustainability Research

• Short term costs (e.g. fuel taxes) more
  significant influence on travel behaviour than
  urban form (Breheny et al, 1998) but...
• Long Term Importance
• Built environment massive fixed capital
  investment, path dependence. Affects costs and
  viability of different transport modes for
  decades, even centuries.
• Future Energy Costs and Climate Change
• Cheap energy era likely ending. Inefficient
  cities rustbelt of 21st century? Currently
  unprecedented urbanisation and climate change
  risk.
• More impetus than ever to improve urban
  sustainability. Need better understanding of
  relationships between urban form and
  socio-economic processes.

6
Monocentric and Polycentric Cities

• Traditional Monocentric City
• High density urban core where accessibility
  greatest and agglomeration benefits maximised.
  Radial dense nature encourages public transport.
• Specialisation / Diversity Tension
• Arguments that high density core creates mix of
  uses (Jacobs, Alexander) and conversely that
  central agglomerations push out lowest value uses
  (Alonso).
• Monocentric Inefficiencies?
• Long distance tidal commuting patterns with
  live/work divisions, congestion, lack of land.
• Post-Industrial Push and Pull Forces
• Widespread automobile ownership creates potential
  for agglomerations in off-centre locations-
  cheaper land, less congestion. Currently cities
  simultaneously affected by forces of
  concentration and dispersion.

7
Consensus on Sustainable City Form?

• Dispersed Concentration Framework
• High-density mixed-use ideas revised for
  hierarchical network of centres. Fractal
  structure incorporates agglomerations at multiple
  scales. Greater potential for live/work
  relationships in sub-centres.
• Classical Theory
• Proposal has similarities to historic Garden City
  ideas and Central Place theory, though applied at
  intra-urban (not inter-urban) scales.
• Questions
• Empirical evidence? Relationship with
  agglomeration economies for different industries?
  Peripheral centres car based? Live-work
  relationships at different scales?

8
Local Scale Urban Form

• Local scale cannot be overlooked. Relevance to
  sustainability issues, and to empirical measures
  of urban form.
• Sustainability Issues at Local Scale
• Density planning without considering built form
  likely to fail (Sherlock, 1996). Permeability,
  street network.
• Quality of life factors- urban vitality vs. town
  cramming. Balance between density and
  liveability.
• Urban Development
• Local scale where urban change occurs. Economic
  factors driving urban development can be
  considered with property and planning permission
  data.
• Creative destruction- speculative development
  dominates property industry, driving growth
  (sustainability costs are externality).
• Example of City of London transformed during boom
  (Batty, 2005).

9
Relevance for London

• Rapid Expansion of London
• Massive employment growth, and immigration led
  population growth. (Crash implications!?).
• Planning Policy in London
• Recent policy based around central growth model,
  enhanced radial transport. Most sustainable
  approach or could dispersal have benefits?
• Conclusions
• Unresolved debate in monocentric and polycentric
  city forms. Need for better data and analysis of
  urban form at multiple scales, linked to
  socio-economic urban processes and development.

10
Incorporating Urban Form Geography and Geometry

• Aggregate Methods in Urban Geography
• Powerful for larger scale city-wide phenomena.
  Compliments socio-economic data.
• Problems with MAUP and handling finer scale data
  such as urban form. Typically measured indirectly
  e.g. population density.
• Approaches to Measuring Urban Form
• Geometrical methods in architecture, planning and
  morphology. Restricted in scope due to high data
  volume and complexity.
• Increasingly data and computing power available
  for geometrical analysis of whole city (Batty,
  2001). Methodologies still in development.
• Geographies to Incorporate Urban Form
• Remotely sensed city (Longley, 2002), detailed
  physical representation.
• Address geography, linked to function and
  property data at building premise level.
• Network geography, accessibility at street and
  pedestrian level.

11
Data Models for Integrating Between Scales

• Methodologies?
• Amazing range of new data. Need methods to
  integrate fine scale data, and aggregate at
  multiple scales respecting urban form. New
  geographical approaches emerging.
• Address Matching at Fine Scale
• Spatial address infrastructure greatly improved
  (OS AL2). Unit postcode links straightforward,
  then individual address possible.
• Block Based Aggregation
• Buildings between streets.
• Street Based Aggregation
• Streets themselves are units used.
• Larger Scale Grid
• City wide representation, try to avoid MAUP
  problems with zones (but may need to join to
  zones).

12
Density Analysis- Centres of Activity

• Economic activity in particular urban areas with
  distinct density and accessibility patterns.
• Urban Activity Centres Typology
• Traditional monocentric and more recent
  polycentric trends overlapping in world cities
  (Hall, 2003)
• Central Business Area
• Expanded Central Business Area
• Tertiary Business Developments
• Outer Centres
• Edge City Developments

Testing Theory with Data Use urban form/function
database to test theory, quantify in London
context, define relationships between density and
accessibility.
13
Density and Valuation Office Data

• Great Potential
• Address based data of commercial property
  including detailed function and floorspace. Fixed
  at 2005.
• Rateable Value Issues
• Calculated as floorspace multiplied by use factor
  (office generally higher) and a smaller rent
  related factor. Possible to work backwards to
  separate values, but complicated and not yet
  complete.
• Useful Proxy of Employment?
• Good fit for office employment, but variation at
  lower densities. Likely caused by lack of
  calibration for other employment e.g. industrial,
  retail.

14
Office Density Analysis
Monocentric Dominance of central agglomeration,
merging into inner city.
Tertiary Centres Canary Wharf. Hammersmith?
Outer Centres Much lower density, various scales.
Largest Croydon, Kingston, Uxbridge.
Edge City Difficult to identify here. Need mix of
uses and travel.
Inner City Distinctive inner city area at medium
density. Leading into Western corridor highlights
West/East split. Change over time? Recent change
reinforcing central dominance.
15
Retail and Local Services Density Analysis
Smaller Scale Agglomeration Retail and services
functions in more dispersed network. Linear
streets visible in retail patterns.
City of Villages Whilst office very
monocentric, retail and services in polycentric
network at range of scales.
Mixed Use Visualisations Possible to combine
functions to visualise mix of uses. Here office
(blue) combined with retail (yellow).
16
Accessibility

• Descriptive analysis so far. Can we try to
  explain current urban form patterns?
• Public Transport Accessibility
• Major influence on activity centres in London,
  both historic and current growth.
• Potential Measures
• Measure how much is accessible within a certain
  cost e.g. population accessible within 45 minute
  public transport journey.
• Fine Scale Accessibility
• Network analysis of local street network, can
  consider more pedestrian focussed and cognitive
  representations of city.
• Potential Accessibility and Travel Behaviour
• Important to consider relationships between
  potential accessibility and actual travel
  behaviour.

17
Density and Accessibility
18
Density and Accessibility Conclusions

• Expansion Policy in London
• This analysis agrees with current policy that
  highest density employment achieved at highest
  accessibility levels, and Inner City greatest
  potential for expansion.
• Outer London Unsustainable Patterns?
• Outer London centres achieving better than
  expected density given access levels. This due to
  car access or more local travel? Back to
  Monocentric and Polycentric discussion.
• Need actual travel data to categorise trends in
  Outer London and distinguish between Outer
  Centres and Edge City developments.

19
Travel and Sustainability- Distance and Mode

• Greater car use to suburban employment
  destinations, so often described as less
  sustainable.

Distance and Mode Efficiencies This analysis
ignores distance travelled and energy used in
public transport journeys.
Walking and Cycling!
20
Travel and Sustainability- Outer London Diversity

• Possible to calculate average carbon per journey,
  using distance and mode data.

Edge City No longer centre-suburbs split, but
edge city vs. rest split. Car dominated office
parks by far least sustainable. Suburbs Most
Sustainable? Closer live-work relationships and
more active transport. Central London public
transport dominated but long distance. Outer
Diversity High variation in Outer Centres, and
simple central-suburbs divisions inaccurate.
Missing Economic Specialisation People travelling
further to centre for more specialised productive
jobs. Should be considered.
21
Economic Specialisation and Sustainability

• Economic Specialisation Proxy
• Use census data on employment categories. Sum the
  top three categories for proxy.

Outer London Mix Most Outer Centres lower
productivity jobs. Many Edge City high
productivity, not back office. Specialisation and
sustainability tension.
Combine Economic Specialisation and
Sustainability Best combination in West London
centres. East fares much worse. Market favoured
West, why? Image and closer to workforce? Also
local scale factors?
22
Conclusions of City Wide Analysis

• Monocentric, but Polycentric Trends
• Historic centre dominant and expanding, but
  diverse polycentric trends at fringes. Centre
  combines very high economic specialisation with
  reasonably sustainable travel.
• Outer London Contrasts
• Outer London includes least sustainable (but
  productive) edge-city developments, along with
  most sustainable town centres with high live-work
  integration. Many outer centres lagging in
  productivity.
• Support London Plan approach?
• Central agglomeration focus balancing economic
  and relative sustainability. Questions of
  intensification impacts at local scale.
• Polycentric Issues
• Notable car based edge city trends in West. Outer
  town centres high sustainability but mixed
  economic success. Could potentially expand role
  in employment, but need to overcome market bias.
• Town centre failures in East London agree with
  plans regeneration focus.

23
Integrating Local Scale Analysis

• Focus of the research is integrating city wide
  trends with changes at local scale.
• Questions for Local Scale Analysis
• Are local urban form issues contributing to the
  highly variable economic and sustainability
  trends in Outer London centres?
• How is intensification in Central and Inner
  London impacting urban texture, mix of uses and
  live-work relationships?
• Currently Analysis Not Complete
• Research at local scale ongoing.

24
Intensification and Mega-Development

• Opportunity Areas
• Low density and high access levels, priorities
  for expansion.
• Brownfield railway and docklands, British
  Waterways/railway companies acting as land
  developers.
• Block Level Visualisation
• Explore density data related to Opportunity Areas
  (shown as transparent blocks). Block level good
  intermediate geography, represent urban texture.
• Analysis of Mega-urban development
• New scale of property investment transforming
  locations. Private sector led master-planning at
  extreme densities, often isolated from
  surrounding urban fabric.

25
Mega-Urban Development at Local Scale

• Canary Wharf Debate
• Canary Wharf mega-urban archetype. City of
  Spectacle.
• Economically very successful (likely to be hit by
  downturn), public transport success but socially
  divisive, live/work failure.
• New Urban Form?
• Street network fundamental to traditional city,
  multiple functions key to success, but density
  limits.
• Innovations in London to overcome space
  restrictions-
• London Underground
• Raised pedestrian concourse (failed).
• Multiple levels in mega-developments.
• New Mega-Urban Developments
• Intention is that newer developments avoid past
  mistakes. Stratford currently showing familiar
  signs.

26
Conclusions

• Great Potential in Geography and Geometry
  Concepts
• Integration of socio-economic and built
  environment data opens new research
  possibilities. Shown particular employment and
  urban form structures in London. Methodological
  challenges in integrating between scales.
• Monocentric and Polycentric Discussion Important
  Debate
• Complex interaction of economic, social, and
  sustainability factors. Likely greater potential
  for dispersed growth in London, but significant
  differences between Outer Centres and Edge City.
• Local Scale Factors
• Ongoing research. Significant trends in
  mega-urban developments and Outer London
  variation.

27
Analysis and Methodology Weaknesses

• Missing Social and Demographic Considerations
• Residential considerations (family orientated
  environments, housing market divisions) huge
  influence on live/work relationships, as are
  education and skills disparities. Currently
  conducting housing market research, need to
  integrate this with sustainability analysis.
• Temporal Analysis
• Density data fixed in time. Have access to London
  Development Database for new completions and
  permissions, one route. Greater use of ABI
  employment data needed, currently problems at low
  spatial resolutions.
• Employment / Sustainability Simplifications
• Various proxy measures should be more rigorous.
  Rent information also missing from analysis and
  should be incorporated.
• Technical Issues Regarding Spatial Joins
• Cant entirely avoid MAUP issues.
• Physicalism Critique
• Need to bear in mind, and focus on socio-economic
  links to urban form, not just urban form on its
  own.

28
Related Research Opportunities

• Network Research
• Building Energy Research
• Land Use Transport Modelling
• Lots more possibilities with new data and
  analysis methods. Database intended to be used
  and contributed to by other researchers (some
  licensing issues for particular datasets).

29

• Thank you for listening! Welcome comments and
  questions.
• Contact Email duncan.a.smith_at_ucl.ac.uk
• Like to thank the following data providers for
  this research
• Ordnance Survey
• Valuation Office
• Infoterra
• Greater London Authority

30
References

• Alexander, C. (1974). A city is not a tree.
• Alonso, W. (1964). Location and land use.
• Batty, M. (2000). "The new urban geography of the
  third dimension." Environment and Planning B
  Planning and Design 27 483-484.
• Batty, M. (2007). "The creative destruction of
  cities." Environment and planning. C, Government
  policy 34(1) 2.
• Breheny,M.,Gordon,I.,Archer,S.(1998), Building
  densities and sustainable cities, Engineering
  and Physical Sciences Research Council (EPSRC),
  Sustainable Cities Programme, Project Outline No.
  5, June 1998.
• Burton, E. (2002), Measuring urban compactness in
  UK towns and cities, Environment and Planning B
  Planning and Design 2002, 29, pp 219 250.
• Urban Task Force (1999). Towards An Urban
  Renaissance, E FN Spon.
• Foster (1999), Docklands Cultures in Conflict,
  Worlds in Collision, UCL Press, London.
• Jane Jacobs (1961) The Death and Life of Great
  American Cities New York Vintage Books (NA
  9108.J17)
• Jenks, M, Burton, E., Williams, K. (2000) The
  Compact City A Sustainable Urban Form?, (Spon.
  London).