London Density Debate
Anne Power, LSE
Monday 19th June 2006
Understanding density
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Changing ideas
Successes and failures
Sustainable development
Lessons for tomorrow
Negative images of density
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Council tower blocks
Back to backs
Overcrowding
Family deprivation
Hong Kong
DENSITY evokes historic failures
Positive images of density
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Old grey stone flats (Edinburgh)
Georgian terraces (inner London)
Victorian semi-detached villas (industrial cities)
Dense blocks (Paris)
Hyper density (Barcelona)
city centre warehouses – canal revolution
traditional villages – Cornwall, Yorkshire
cathedral cities – York, Chester, Lancashire
DENSITY correlates positively with high value
Density numbers and ranges
Type
Density per hectare
By-law housing and terraces 200
Inner city balcony estates
150
Post-war New Towns
40
Modern suburban estates
23
New private developments
30 - 400
Density is a critical issue
• Shrinking household size
– therefore, halved people density since WW2
– therefore, many services unviable
• Changing shape of households
– many less children
– later marriage and child bearing
– lone parents
– older people
Density is a critical issue
• Shrinking land supply
– because: crowded, urbanised island
– population growth
– dense land use
– sprawl buildings
– growth of cars and roads
– increased wealth/space per person
– environmental constraints
e.g. water, waste, traffic
Critical Mass means density
• Need for critical mass of people to support
regular bus, local shops, school
• 50 homes per hectare is minimum viable
density for community provision
• Rapid splintering of households changes
needs
• Anorexic?
• Households – 8:1
• People – 25:1
Proximity and density
• Proximity is critical
• Elderly, youth, lone parents:
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Social provision
Mixed communities
Social integration
Supervision and safety
Public versus private transport
Public versus private space
• Therefore, moderate density is a MUST - 50
homes per hectare
Land supply means higher density
• Conserving green fields is popular
• Protecting flood plains is essential
• Green belts are popular and help cities
Expanding within existing settlements
• Restoring damaged land
• Analysing/understanding capacity; uncounted ½ acres
• Reusing, remodelling buildings
• Infill sites, windfall flows
• Therefore, the potential for recycling is huge
Current patterns are unsustainable
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Congestion and car use worst in Europe
Flood threats greater than most countries
Cost of infrastructure for new settlements
Most urban areas adjacent to each other
Development impact covers 75% land
Global pressures are intense,
e.g. energy use, migration
Growth agenda
• Growth areas are “low density sprawl”
• New settlements detract from existing
communities, e.g. Harlow, Dartford
• Traffic pressures make plans untenable
• Public/private infrastructure funds paltry
• “high impact, uninsurable, car born, ugly”
• Vote loser
• Alternatives within existing communities
Market renewal agenda
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Hot opposition to clearance
“slums” or communities?
Fast recovery in weak markets
Massive capacity in older industrial cities
Urgent need to densify - Manchester
Fast rail links working
Alternative to clearance and outer building
Renovation and infill
Manchester
Lessons – existing communities
offer huge potential
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Existing stock needs constant renewal
Energy saving requires reuse
Density requires detailed local knowledge
Design, quality, mix are crucial
Families need adaptable, proximate space
Big gardens have limitations
Parks are priceless assets
Paying true cost clarifies choice
Taxing gains helps
What is sustainable?
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Cutting energy use by 60% by 2050
Alternatives to car
Supporting large elderly population
Preventing sharp racial separation
Protecting/enhancing natural capital
Making good environmental damage