The question of density
This subject follows on from the issues of ribbon development, sprawl and
urban containment ( i.e. green belt) in that there is an argument that the
pressures for new housing would have less damaging effects if housing was
built at higher density, implying less use of greenfield or undeveloped land.
The 2011 census indicates that the population has grown by about 7% in the
last decade. Britain is one of the few European countries where this
population trend is expected to continue and hence the importance of relating
population growth to “population density". London's population is growing at
12% (twice as fast as 20 years ago) whilst in some of the northern region's
population is shrinking with empty houses and vacant school places. In fact,
the population in London and its growth is not evenly distributed. Tower
Hamlets and Kensington and Chelsea show the highest population density,
notwithstanding problems of gross and net density calculations, the latter
taking into account parks and other unique features. It is expected that
meeting population growth for the next 50 years will increase the developed
area of England from 10% to 13%. (See variable and regional estimates in
previous module)
Going solo: one of the important factors in calculating the need for new
housing is making an accurate estimate of household size now and in the
future. Clearly the average size of household will affect the density of the
population arising from the number of dwelling built on any area of land. The
decline in average household size has leveled off, possibly due to the
economic difficulties that young people have in forming new households.
However, were there a sufficient supply of small dwellings it seems likely that
household size would continue to decline. See Klinenberg E 2012 Going Solo:
The Extraordinary Rise and Surprising Appeal of Living Alone Penguin.
Klinenberg sees living alone as a remarkable social experiment as the first
time in human history when large numbers of people of all ages are settling
down as singletons. In some cases this is a force of circumstance, later
marriages, divorce and bereavement rather than choice. In the UK 34% of
households had only one person living in them, in the US it's 27%, with
Sweden ‘leading’ the world at 47%. The tendency is more prevalent amongst
women, and the young comprise the fastest-growing number of single person
households. The rates of fastest-growing one-person households is in China,
India and Brazil.
This trend will have serious consequences for resources. But there are also
questions about what this means for mental health and social fragmentation?
What does it mean for the way we build our cities? The drivers are a
combination of wealth and readily available social security (ie state provision
as an alternative to family support) - those who can will. Pandering to privacy,
has been one of the features of post WWII planning and architecture that may
have contributed to a loss of a sense of community. Alternatively the pattern
of residential development might be the response to social fragmentation with
other causes. In either case there might be lessons to be found in Durkheim’s
analysis about alienation and anomie. Durkheim, Emile 1951 Suicide : a study
in sociology The Free Press. In terms of mental health housing providers
could disclaim responsibility if people can feel just as alone when in a crowd
or on the 15th floor of a tower block.
Going solo was discussed in 31March 2012 through interviews with a number
of people living alone. “Living alone should not be equated to loneliness.
There's nothing more lonely than living with the wrong person.” Klinenberg
says that this trend has produced significant social benefits. The revitalisation
of cities and participation in public life? He claims that living alone can be
more environmentally sustainable as singletons prefer apartments rather than
big houses in inner cities rather than suburbs? Really? “I don't have to excuse
myself, explain myself… (on children) I have insufficient self-esteem to need
any duplication of myself in the world… Living alone means freedom… It's not
about selfishness, just knowing what you like and doing what you want
without having to take another person into account. Okay that sounds selfish
but if you're going to be selfish and is probably best to do it on your own…
And I know eventually change will come… So instead I have found ways of
making aloneness feel less lonely. Downsizing from my family home, flat was
a help… No more empty bedrooms.” Then there were the comments of those
less happy with their singledom, “… things with most meaning to me always in
my eye line… Cooking for one seems too much effort… I still think it's not
natural… If it were left to me I'd make us all living longhouses… We need
each other and especially the old… two is good when paying electricity bills…
Cohabitation seems a greater leap in cities because it's all the harder to
extract oneself if things turn sour. … It's what keeps otherwise functional
adults living with their mothers… I own a cat… We are social animals… An
extraordinary freedom. I just wonder how fragile [solos] are and what it might
take for us to rediscover how much we need other people.”
However, a remarkable change has occurred in the composition of
households. The number of households with 3 or more generations living
under the same roof was increased by 7% in the past 5 years reaching levels
last seen in the Victorian times.
Before leaving the subject of social interaction there is the recent
phenomenon of social media and the communications revolution that allows
people to enjoy an intense social life even when living alone. Journalist
Francis Hope described another form of in-between state, “Heaven is the
ideal state… when one is alone but expecting company.… A perpetual lunch
date lunch date in an hours time. " He found more pleasure in the expectation
of company than in the meeting itself. In fact, to have the meeting would
cause the inconvenience of having to arrange another.
Resources: Them seems to be little doubt that sharing space and facilities
with others could lead to less use of a number of important resources; space,
water, heat and materials required to build stuff. Normally, dwellings need
only increase the bedrooms to accommodate additional household members,
sharing kitchens, access/corridors and reception rooms. Notwithstanding a
trend to increase the number of bathrooms, many older houses still have a
“family" bathroom with possibly a small en-suite with the master bedroom.
While water for washing and flushing might not be shared that for gardens
and cooking normally is. The economy on space heating will depend on the
controls of the system but the heating of all common parts would obviously be
shared.
Density in the round: In a recent study, Cooper R and Boyco C 2012The
Little Book of Density Lancaster University] density was found to have many
dimensions, including relationships between a number of important factors
fundamental to existing and new built-up areas. At least indirectly, density is
a factor impacting on our quality of life and mental and physical well-being.
23 different measures of density were identified although, in fact, only
dwellings per unit area is in general use and has incumbency. The reason that
‘bed spaces’ is not used as a measure is normally due to uncertainty as to
whether the beds are actually slept in (although there is no less uncertainty
about how many people live in each dwelling). However, data in respect of
dwellings per acre or hectare is most easily obtained.
Cooper and Boyco looked at 75 studies which included density in their
analysis and sought opinions from 129 built environment professionals. The
general perception is that in areas of higher density there was better support
for public transport and less car ownership and use. However there are more
pedestrian casualties and people walk less for leisure purposes. Building at
high densities is more energy-efficient. There is a negative impact on mental
well-being at higher densities resulting in depression, withdrawal, strain, and
poorer quality of family life. Less privacy means less friendliness. High
densities contribute to increases in the occurrence of adolescent obesity,
increased rates of heart disease and more drinking amongst adults. High
densities create better social situations in terms of equality and mixed tenure
(including affordable housing) than do lower densities.
In terms of the design of residential areas, low densities were regarded as
about 23 dwellings per hectare, medium densities at 44 dwellings per hectare,
and high densities at 79 dwellings per hectare. 30 d/h or 12 p/a is the current
norm outside central urban areas.
The top 3 drivers identified for higher densities were the efficient use of land,
increased profitability and more viable public transport. This aligns with the
predominant belief that it is developers and local authority planners most
involved in density decisions. Urban designers and architects are 4th and 5th
likely to influence density decisions. Those surveyed thought that the LPA
should be most influential and developers 7th.
Cooper and Boyco concluded that there is a lack of thinking about the future
(sustainability and resilience) when considering density, with an
overconcentration on the present context. Having access to studies from
around the world would serve to demonstrate what good density looks like
and how it functions. Such comparables would be useful in making some
more informed density decisions. In fact, Lord Richard Rogers has for many
years used Barcelona as what he sees as a templat of well functioning
urbanism. When it came to the important issue of sustainability, there were
unanswered questions about what densities would prove to be sustainable
and for whom?
Official advice:The Government’s 1992 Planning Policy Guidance Note 3 on
Housing suggested that there was no longer any need to pack houses
together at 20 or 30 to the acre and the 2000 revision discussed achieving
high quality housing and the assessment of design quality “… Well laid out so
that all space is used efficiently, is safe, accessible and user-friendly… Is well
integrated with and complements the neighbouring buildings and the local
area more generally in terms of scale, density, layout and access.” (emphasis
added).
PPG3 2000 urged the Effective use of land: concentrating on use of
previously developed land (brownfield) and efficient use of land, LPAs
developing housing density policies should have regard to demand and need,
infrastructure capacity, adaptation to the impact of climate change,
accessibility (particularly public transport), characteristics of the area
(including mix of uses) and the desirability of high-quality well-designed
housing. “Reflecting the above, LPA's may wish to set out a range of
densities across the plan area rather than one broad density range although
30 dwellings per hectare should be used as a national indicative minimum to
guide policy development and decision-making until local density policies are
in place." The density of existing development should not dictate that of new
housing by stifling change or requiring replication of existing style or form. If
done well in terms of the design and layout new development can lead to a
more efficient use of land without compromising the quality of the local
environment." As a boost to the supply of housing paragraph 47 of the
National Planning Policy Framework 2012 suggests rather blandly that local
planning authorities should “set out their own approach to housing density to
reflect local circumstances". And paragraph 59 counsels against unnecessary
prescription in respect of density. The conclusion could be drawn from official
advice that density is recognised as a measure of the efficient use of land but
not necessarily an indicator of the quality of either a house or residential area.
Garden grabbing; mainly because the PPG3 had classified gardens as being
‘previously developed land’, more suitable for development than greenfield
sites, there was a flurry of applications for developments effectively
intensifying the density of residential areas. In turn, there was a backlash that
caused a specific amendment to the National guidance that required greater
care to be given assessing the impact of such developments. The rate of
planning permissions granted for developments in gardens sharply
decreased.
The Garden controversy: this was a study conducted by Wye College
(University of London) in 1956 into the productivity of gardens in low-density
residential areas. A discussion of this topic is included as a separate module
as an Annex to the Question of Density. Another more recent controversy is
building around the construction of basements in areas of very high land
values (eg Kensington) but which are making very substantial increases to the
floor area of dwellings and the density of the areas. In most cases the
underground accommodation is only suitable for cinemas, and parking rather
than more bedrooms that would increase the population density.
Design and density was published in 2002 by the CPRE as part of its
“sprawl patrol" campaign and in response to PPG3 2000 designed to
“radically alter the way in which we build new homes in this country… And put
an end to the wasteful, badly located and poorly designed house building that
has gone on for the last 20 years. " There were signs of densities falling
towards 20 dwellings per hectare that were unnecessarily wasteful and
densities of 30 to 50 dwellings per hectare were recommended. The CPRE
claiming that “density matters", listing the advantages of the higher densities
as: complementing the character of an area, opportunities for social contact,
sustaining public transport, encouraging feelings or of safety and security,
absorbing parked cars without intrusion, this creating a sense of identity and
improving property values. Wanting to allay misplaced fears, the nub of the
issue was said to be in the design of new buildings and not density.
One of the unfortunate features of older towns and villages is the scale and
appearance of on-street parking that is exacerbated at higher densities.
CPRE fear that density was being controlled by the availability of parking
spaces rather than the quality design. The Briefing then demonstrates the
imprecision of counting dwellings. One large dwelling could vary from
accommodating 8 people and 4 cars to just 2 people and 2 cars (the empty
nest). The same site could accommodate either flats or houses with similar
built forms but accommodating a significantly different number of households
and therefore, people and cars. The level of occupancy appears to be the
most important determinant. In fact, in suburbs and villages under occupancy
is the prevailing factor with over 70% of dwellings having one or more spare
bedrooms.
Nothing gained by overcrowding was published by the Town and Country
Planning Association in 2012 that explained how the Garden City type of
development may benefit both owner and occupier. This was, a reproduction
of a 1912 publication of that name by Raymond Unwin a century earlier.
Unwin explained how the traditional by-law housing layout prevalent between
1870 and 1910 was inherently inefficient in its use of space because of its
excessive street length. By turning the traditional layout inside out, whereby
houses faced outward onto streets but inward onto a huge communal
gardens, effectively street space was turned into garden space. This was the
principle that had been applied by Unwin at Brentham but could not be
claimed as a new invention as it had been the basis for the Norlands Estate in
Notting Hill (1850s) and in Maida Vale West Hampstead between 1870 and
1900. More efficient use of land was equated to a lower rent or at least much
more land and buildings for the money. The average density was 30 dwellings
per hectare, representing a more harmonious combination of city and country,
dwelling house and garden.
Ideas from this report were incorporated into the 1919 Tudor Walters
Committee Report that enshrined 12 houses per acre (30 d/h) that had been
applied at Letchworth. The concept of the superblock minimized the amount
of road required to be paid for by each unit. Roads represent a major expense
and junctions are a loss of developable frontage. This layout is also more
efficient to patrol by police or scavenger cart (sic). The low-density would
mean a larger land take and possibly more roads and drains but Unwin was
much more interested in the quality of the residential environment than in the
loss of agricultural land. However, Unwin also calculated that the actual size
of the town (the distance from edge to centre) would not increase dramatically
giving a guide that an 11 miles radius could accommodate 8 million people
and 14 miles accommodated 12 million in London; about 25% increase in
radius accommodating a 50% increase in population.
Unwin sought to demonstrate that the increased rental value was
disproportionately less than the increase in units. It is still the case that 2
smaller units do not necessarily provide a greater return than one large one..
In 1912, Unwins said that, “Experience has shown that where plots have been
laid out by landowner it is very difficult to induce the speculative builder to a
erect upon them small cottages, even where the demand for small cottages is
very great. It is of great importance when limiting the number of houses to the
acre that the reduction of the number of houses should also have a limit on
the size of the house." One hundred years later the mechanism still does not
exist to provide and maintain small houses of large areas of land.
In summary, the term density is often used when describing housing areas but
there does not appear to be any clear relationship between the number of
dwellings built on an area of land and the quality of the design or of life of the
residents. Due to very variable occupancy rates, the buildings do not always
have a clear relationship with population density. It does seem that with small
and still declining household size, that a large number of smaller dwellings
would be required to create a better balance, and possibly reduce the level od
under-occupation. Unless such dwellings are built on generous plots then
smaller dwellings implies higher overall densities. Finally, there is a useful
concept of Lifetime Neighbourhoods which implies an area where people can
move to meet their changing household needs rather than a Lifetime Home
where such needs can be met without moving. The former would result in
lower levels of under-occupancy (ie efficient use of buildings whether or not
they represent an efficient use of land). This would seem to be increasingly
importance in our search for sustainable development. Such neighbourhoods
are likely to require a range of house types built at different densities.