The Density Debate –
A Personal View
Christine Whitehead
London School of Economics and
Cambridge Centre for Housing and Planning
Research
East Thames Housing Group
The Building Centre London
24 January 2008
How Do We Define Density?
Density is defined very differently by planners and
economists
• Planning densities are defined in terms of
physical attributes – numbers of dwellings or
habitable rooms per hectare;
• Economists are interested in outcomes in terms
of population per hectare and densities of
occupation;
• The two are usually related to one another but
not always; the relationship is changing; and
sometimes inconsistent
Why Are We Interested?
• Important element in the debate about whether
planning policy is too constraining and whether
the emphasis on density is helping to increase
prices;
• Regarded as a core element in the sustainability
and regeneration agenda;
• Strongly related to other policies notably on
brownfield development; Section 106; and
mixed communities – but the linkages often not
understood
Government Policy on Densities
• Requirement to increase residential planning
densities placed on regions and local authorities;
• Formal requirements in PPS3 (2006) actually no
tougher than those in PPG 3 introduced in 2000.
But the rhetoric and the pressures put on
authorities much stronger;
• Interpreted differently in different areas but
generally the pattern is based on location in
relation to the centre and on transportation.
Little emphasis on other aspects of sustainability
(assumed able to respond);
• London’s policy in the London Plan very much
stronger than anywhere else in the country – with
major implications for the size of dwellings and
built form
Actual Densities
• Outside London, densities have been falling – in
suburban as well as central areas;
• In London immigration and population growth
have necessarily increased densities;
• Densities of occupation vary greatly between
different groups of households; between
tenures; and most importantly by income;
• Location and space per dwelling are highly
correlated with one another, in part because of
their relationship to income distribution
Fundamental Tensions
• In a growing economy demand for housing
increases roughly in proportion to income growth
– so if incomes rise by 2% p.a. for twenty years
we want about 50% more housing overall;
• As supply is constrained this pressure increases
house prices; differentially increases the price of
larger units; and increases problems of
affordability at the bottom end of the market;
• Role of planners impossible? Must aim to use less
land; build on more brownfield; achieve mixed
communities; provide more space per person;
provide more units; ensure better design; and
improve quality and services for both
additional and established households
Economic Principles of Planning
• Economic rationale for planning is to overcome
market failures – encourage positive externalities
and discourage negative; improve information;
assist adjustment; and ensure adequate provision
of public open space and services;
• Higher densities address issues of urban sprawl
and the need for diverse and productive economy
– but also costs of too high densities in terms of
pollution, congestion and the loss of value to
individuals;
• Fundamental objective to maximise social value of
development – but while general objectives are
clear, relationships are complex and target based
approaches may produce perverse results
Market Pressures
• Demand for separate units increases with
demographic growth but equally with incomes
across established as well as additional households;
• Income elasticities similar for internal and external
space – and stronger for houses than flats;
• Also evidence of pressures to live closer to the
countryside – but value of local open space
particularly high;
• Some types of household value central locations
and newer migrants generally demand less housing
per household;
• Given a growing economy one would expect to
build at high standards suitable for the future and
to allow older/less appropriate housing filtering
down the system
The Evidence in Densities
• Population densities fell significantly from 1945
up to the 1980s. They stabilised in the 1990s
(1% decline) while densities in London actually
rose by 8%;
• This is partly the outcome of constrained supply
and rising prices;
• England’s urban areas are relatively dense as
compared to other high income countries –
except for central London;
• On wider definitions of London, densities are
high by international standards
The Evidence on Sustainability
• The most quoted estimates that doubling
density halves energy use is based on a simple
correlation and reflects stage of development
rather than a direct relationship;
• Corrected estimates show an impact of well
below 10% and would involve quite unrealistic
policy constraints;
• Higher densities support better public transport
– but the critical figures for this are between
25dph and 60dph ;
• The position with respect to local services –
and healthy living – is even less clear – but
again 50-60dph appears to be the relevant
benchmark
Do Higher Densities Deliver?
• Higher densities traditionally generate more but
shorter trips, using more public transport
• Evidence from the “revived” central urban areas
such as Leeds suggests that as individual
networks expand these trips are getting longer
• The growth of second and weekend homes is
also relevant here as, if people have less space
in the urban area, they substitute other (less
sustainable?) lifestyles
• The most important issues are how the demand
for space can be satisfied and the ways in which
the construction industry is responding to
market and policy pressures
Table 1: Housing Densities in Europe
Useful floor area per dwelling (M2)
Year
Total
Year
Dwellings
dwelling
completed
stock
Austria
2003
93.9
2002
101.0
Belgium
1991
86.3
2001
119.0
Denmark
2002
109.1
2001
112.4
Finland
2002
77.0
2003
90.2
France
2002
89.6
2002
112.6
Germany
2002
89.7
2003
113.9
Italy
1991
90.3
2000
81.5
Netherlands 2000
98.0
2000
115.5
Sweden
2003
91.6
2003
128.0
England
2001
86.9 1981-2001
82.7
The Policy Response
•
•
•
•
•
Rapidly increasing planning densities;
Smaller units with less space per room;
More flats;
Inflexible built form;
More shared ownership rather than social
rented dwellings
Table 2: Density of new dwellings by region:
2000-05
2000 2005 Proportional
Increase
London
56
112
100
South East
24
41
71
North West
26
41
56
North East
24
40
67
Yorkshire and Humberside
22
39
77
South West
25
39
56
East Midlands
22
38
81
West Midlands
24
36
50
East of England
22
35
59
England
25
41
64
Table 3: The Changing Make Up of Completions in England
Completions
2000/1001
2004/2005
Change
( %)
England
1 bed
7
10
2 bed
27
38
3 bed
34
29
4 + bed
32
23
20 (25,970)
41 (63,920)
+146%
80 (103,890)
59 (91,980)
-11%
Total
129,866
155,893
+20%
Number of bedroom (est)
400,000
430,500
+8%
1 bed
18
24
2 bed
48
58
3 bed
25
12
9
6
Flats
58 (8,400)
19,920) 83
+138%
Houses
42 (6,080)
(4,090) 17
-33%
14,492 (11%)
24,063
+66%
Flats
Houses
London
4 + bed
Total
Number of bedroom (est)
33,300
48,700
(av 2.3)
(av 2.0)
- 0.3
Figure 1: Shared Ownership as a percentage
of all S106 completions
40
NE
35
NW
30
Yorks
25
E Mids
20
W Mids
15
Eas t
London
10
SE
5
SW
0
England
2001-02
2005-06
Outcomes
• Rising planning densities but stable or falling
actual densities outside London;
• The London phenomenon – densities rising for
new construction 50% faster than elsewhere;
• A massive change in dwelling composition linked
to declining space standards;
• Increasing reliance on one and two bedroom
flats often with no through ventilation;
• Is there a gap in the market provision of small
units?
• Are we actually adding to the total stock
measured by space?
• Can the mixed communities agenda operate?
What do People Want?:
Market Evidence
• Declining occupancy rates in owner-occupied
sector even in face of rapidly rising prices;
relative decline in the prices of small flats
(supply v demand/distribution of income) –
although new dwelling premium; even initially
occupancy lower than planned;
• Higher densities in the private rented sector –
especially among those relatively new to the
country; increasing overcrowding; rents still
based on capacity to pay not quality;
• Groups who like central/dense living – young;
single; students; less established households;
older people looking for services?
Table 4: Tenure mix of London residents by
migration origin and time in the UK
Owned
outright
Owned with
a mortgage
Social
Rented
Private
Furnished
Private
Unfurnished
Rich
Asylum
Other Poor
UK
Total
Countries
Countries
Countries
Born Population
<3
>3
<3
>3
<3
>3
years years years years years years
1%
24%
2%
6%
3%
16% 21%
19%
13%
32%
6%
23%
11%
32%
43%
38%
6%
64%
21%
15%
35%
48%
46%
16%
21%
56%
37%
8%
26%
7%
27%
8%
16%
8%
8%
8%
9%
5%
4%
6%
Survey Evidence
People buying in the market want:
• Houses rather than flats;
• Larger rooms even if fewer;
• Quality kitchens/bathrooms;
• Flexibility
• Privacy, private space and well managed
communal space;
• Access to shops, transport, and parking;
• Energy and environmental efficiency;
• Not to live in featureless boxes
What do Social Tenants Want?
•
•
•
•
•
•
•
•
More space and larger rooms;
Better and more storage – inside and out;
Houses rather than flats;
To avoid noise pollution and poorly managed/
used communal space;
Better design – flexibility; ventilation; kitchens
and bathrooms;
Good maintenance and rubbish disposal;
Access to parking, shops and transport;
Adequate security
Attitudes to Density
• Density as such rarely the issue except for those
spending large proportions of time at home;
• Those overcrowded in the home notice – and
dislike crowding in the area more;
• Conflation between density and high rise – in
people’s attitudes ;
• Concerns about interaction between new high
density buildings and the established
neighbourhood
Three Examples
• Vienna 1929 – Luxury Art Deco for the masses
(50 sq m per unit and lots of services) – now
80% plus “known to the police”
• China in 1990s – 7 sq m per person; 2007 28m2
per permanent resident for new construction;
current government aspiration 100 sq m per unit
• London 2007: Homes for nurses at St Thomas’
Hospital – 230 flats for 400 plus hospital workers
in 5-20 storey apartment blocks mixed with 330
private flats in separate buildings
Conclusions (1)
• Perceptions of density thoroughly mixed up with
overcrowding; built form; location; and attitudes to the
neighbourhood
• Urban England remains relatively densely populated.
Only very central areas have below average densities as
compared to other richer countries
• The benefits of higher densities are overstated and
anyway depend on existing development far more than
on new construction – especially if people move away
because of higher density development
• Only in central London is there a case for much higher
densities
Conclusions (2)
• Higher densities, and especially high rise must
be associated with high quality design and
better services. Even so they will only be
suitable for relatively small groups of mainly
better off households;
• Within central London a case can be made for
iconic; well-managed; high service charged,
super density close to good open space, local
services and transport;
• If these attributes are forgotten the result is
likely at best to be extremely poor value for
money and at worst the slums of the future
Conclusions (3)
• The case for increasing planning densities at
the lower end of the density scale is strong in
order to maintain efficient services. However
to be successful this policy must be combined
with better designed homes which provide
more space per household and greater
flexibility – so that people actually want to live
there now and in the future