Why It Matters Residential Dwelling Density
Summary
We have estimated the number of dwellings in a given postcode, as well as the area’s density of dwellings and the expected number of residents per dwelling on average within the neighbourhood.
| Dataset | Explanation |
|---|---|
| Average Postcode Population per Dwelling | We have estimated the average number of people that live in each dwelling within your postcode. |
| Average Borough Population per Dwelling | We have estimated the average number of people that live in each dwelling within your borough. |
| Average Postcode Population per Dwelling Variance | We have calculated the population per dwelling varience in your postcode compared to the London-wide average. |
| Average Postcode Dwelling Density | We have estimated the average number of dwellings per hectare in your postcode. |
| Average Borough Dwelling Density | We have estimated the average number of dwellings per hectare in your borough. |
| Postcode Dwelling Density Variance | We have calculated the dwelling density varience in your postcode compared to the London-wide average. |
| Postcode Dwelling Density Z-Score | We have calculated how many standard deviations above or below the mean the dwelling density in your postcode is compared to the London-wide average. |
Definition
This set of analyses is all based on the number of residential dwellings in your area. To define what is and isn’t a residential dwelling, we borrowed the definition of a “dwelling” as used in the most recent census. For our analysis, a dwelling essentially includes each and every premises used for the purposes of providing accommodation (whether as communal accommodation or not). So for example, a shared flat would count as a dwelling, whereas a “granny annexe” appended to the side of a detached family home would count as two dwellings.
Why the metric matters from a commercial inhabitant’s perspective
The relative residential dwelling density within a given area is a consideration for commercial inhabitants because, in most cities, including London, there has always been a higher concentration of workplaces, retail businesses, public agencies, cultural events and leisure facilities in areas that have historically exhibited higher relative residential dwelling densities than in the peripheral parts of the city. Resultantly, land values in areas with higher relative residential dwelling density have traditionally been pushed up above the average due to increased demand. Whether residential dwelling density was the cause or the symptom of the concentration of activity remains a point of debate.
What is conclusive, however, is the fact that a higher residential dwelling density in a neighbourhood provides a ready population base for various types of local commercial facilities. Business that have historically prospered in areas with relatively high residential dwelling densities have focussed on providing spatially dependent basic physiological amenities, such as grocery/convenience stored, coffee shops, pubs and restaurants.
Spatially dependent social business such as cinemas, theatres and gyms have also tended to fare well. Business that have historically not fared so well in relatively high residential dwelling densities have been those predicated on being geographically close to their customers, but have witnessed competition from non-geographically dependent alternatives such as clothes shops, home improvement stores and taxi companies. In summary where the average distance from a resident population to a commercial service matters to a business’ survival, they would be well advised to be located in an area with relatively high residential dwelling densities. Where this is not the case commercial inhabitants would be better off being situated where competition for land is less fierce.
Why the metric matters from a residential inhabitant’s perspective
Residential dwelling density is an important consideration for residential inhabitants of a neighbourhood primarily because dwelling density is what makes the difference between living in the proverbial “big smoke” and a more sedate experience of the city. As relatively high residential dwelling densities allows average distances from residences to local amenities and social contacts to shorten, so lessens the perceived level of effort required to access local amenities and opportunities for social interaction- as such destinations are more easily reachable on foot, public transport or by bicycle.
Furthermore, it is generally accepted that residents of areas with relatively high residential dwelling densities have a greater number of destination choices available to them, which has been shown to increase the sense of community as residents actively choose leisure and retail destinations within their neighbourhood. The downsides associated with relatively high residential dwelling densities stem from the fact that a greater number of residents is likely to result in increased competition for public resources- be it coveted school places, or a choice residential location which has, in repeated studies, been shown to cause land values to be higher as compared to areas with lower residential dwelling densities.
Architects and planners generally use the term “building typology” to refer to a range of typical structures. In the field of housing, at the lower densities, these include such forms as single-family dwellings, semi-detached units (duplexes, etc.), row houses, and secondary in-law units. Middle densities can generally be achieved with stacked walk-up townhouses or flats. At the highest densities, elevator- and corridor-accessed units are necessary. Parking arrangements generally form a gradient that corresponds to these increases. It progresses from individual garages, to common surface lots, to podiums or basement garages. The range of application of different construction types is determined by local interpretation of national building codes. But there are common variables, and these may be used to arrive at a common index of construction cost. Generally, as densities increase, building construction changes from wood-framed Type V construction (up to 50 feet) and Type III construction (up to 65 feet), to concrete and steel-framed Type I and Il construction for mid- and high-rise buildings. For units located more than 75 feet above the ground, the introduction of special life-safety code requirements has an important impact on building design.
High-rise housing is a way of increasing residential density to enable more people to live close to the centre of the city (Photograph: Jonathan Billinger, geograph.co.uk)
General commentary
Over the past few decades, residential dwelling density has become a crucial measure of how amenable an area is. The positive externalities associated with high residential dwelling density have been cited as the containment of urban sprawl, improved access to services and amenities, reduced car dependency and more frequent use of active travel/public transport.
The counterargument, however, is that higher residential dwelling density does not automatically guarantee the aforementioned positive externalities. Champions of lower residential dwelling density cite a range of negative externalities as being attributable to higher residential dwelling density such as the depletion of open spaces, overcrowding and inflated land values (particularly around transport nodes). As with most things whether you seek out lower residential dwelling density, as London offers in its suburbs, or you don’t feel at home outside the action of Central London is completely subjective.
Residential dwelling density is also often only considered in relation to its extremes. The very mention of high residential dwelling density often evokes images of high-rise towers blocks. While lower densities conjure up images of suburban or rural living. In reality, it would be an oversimplification to understand residential dwelling density without also considering employment density, given that non-residential development makes a significant contribution to the overall massing of buildings in many London neighbourhoods. We’d advise you to think of residential dwelling on a sliding scale.
At the upper end of the scale, high residential dwelling density would be typified by the existence of many tall residential buildings closely clustered together and not much space allocated for non-residential uses, such as main roads, retail, employment. Worlds End Estate in the borough of Kensington and Chelsea is a good example of high residential dwelling density. Medium residential dwelling density would be exemplified by London’s heritage housing. Think of the Victorian mansion blocks around Battersea Park, Knightsbridge and Maida Vale.
Their building heights allow for more dense residential arrangements, and they have roughly allocated 25% of space to or for non-residential uses. Low residential dwelling density is largely constrained to the outer suburbs of London which in accordance with the demands of earlier generations of Londoners, were developed at much lower residential dwelling density. Even though less than 25% of available space is used for non-residential purposes, the terraced and detached, mainly 2 storey housing with gardens, uses up more land resulting in a much lower density than medium residential dwelling density areas.
Trivia
London has among the lowest densities of any global city. New York City fits the same population onto just over half the land mass. London is also about 50-60% as dense as Paris and less than one third as dense as Seoul, South Korea.
History
The density of development in London today is a product of its evolution. By the early nineteenth century, the residential dwelling density in London was already comparatively high, especially in the inner-city areas. These were chronicled in the 1800s in the poverty surveys of William Booth and others.
By 1930, the influence of public transport, and automobile use, catalysed London into a city with lower residential dwelling densities, with a little help from new town planning rules and the application of Garden City principles. Come the 1940s, the combination of wartime bombing, slum clearance and the decline of factory based employment, fuelled a flight to the suburbs and in many instances out of London altogether.