In order to better understand the architectural language of density it is necessary to have some visual clue as to what is meant by so many dwellings per hectare or habitable rooms per hectare and the easiest way to understand this is by visual reference to existing housing types, in other words streets within our neighbourhood or known to us.
In the new planning system introduced after the Second World War there was an attempt to impose a new order. A series of plans were produced for the development of large cities. Particularly influential was Patrick Abercrombie’s plan for London.
This proposed a hierarchy of densities for new housing development: 200 persons per acre (ppa) at the centre, 136 in the inner areas descending through 100 and 75 ppa to 50 ppa at the periphery.
The twin priorities of urban planning were preserved – relatively high densities in the slum clearance areas with the low densities of the Garden City movement in the suburbs.
or -> HERE <- in case it ever disappears from the above link.
Much as I like my own blog there doesn’t seem much point in you reading on without having read this treatise on the subject of density above by Graham Towers which pretty much covers the subject.
In fact the only point in reading on is if you wish to view illustrations of housing density. See also Tower blocks and the density myth and get hold of a copy of Modern Terrace Houses Researches on high density development by A. Trystan Edwards.
Unfortunately there would appear to be a difference of opinion between CABE and MJP when counting dwellings per hectare. So where possible I have included both figures.
The following picture taken from a report by CABE illustrates the most common house types and their density.
Click the drawing above to see the full picture
Picture taken from:- http://www.cabe.org.uk/files/better-neighbourhoods.pdf or here when CABE closes.
Richard Rogers has commented on the preponderance of small high rise flats in relation to density in the following article in Building Magazine.
Rogers also responded to criticism that the Labour’s density requirements, contained in PPS3 planning guidance, have resulted in the construction of far too many high rise flats without gardens. He said: “Clearly the designs [under PPS3] could have been better. But single family homes can be built easily at 50-70 homes per hectare, for example the regency houses that everybody loves.”
Greenleys MK at 25dph – click to see aerial photograph
30-40dph is the figure given by CABE
This gives some idea what a suburban / garden city layout would achieve in terms of residents.
Wolverton MK at 52dph – click to see aerial photograph
60-80dph is the figure given in the CABE document for Victorian terraces
A former railway town that built steam engines according to a resident of Aylesbury Street that I met (25/3/2010). The town has a visible industrial past.
Mews housing at 85 to 95dph
Apparently Accordia has some, I’ll have to check it out… download pdf on Accordia here
Flats at 180dph (ish) – click photo for area shot
I took the above photograph on 16th June 2010 at Great West Quarter Brentford. I can’t say for certain that these flats are 180dph but they cetainly fit the model provided by MJP Architects in sustainable suburbs. If you value easy access to a major city artery and can live with large areas of hard standing and a rather stark urban environment then this is probably the place for you. I found it a bit harsh, although to be fair there is parkland to the East.
Here’s John Robert Gold on the same subject, “What had become clear at the start of the 1960s was that high densities of 136-200 persons per acre (336-494 persons per hectare) could be achieved without recourse to high buildings.”
From a film on the BBC website:-
“Well take Belgravia there’s about 200 people per acre living there, you couldn’t call that a slum, but the planners argument is that high density means slums, you know, doesn’t follow. The streets are the city for me, where you can walk the streets.”
HIGH DENSITY SCHEMES THAT WORK
Click photograph for area shot
There’s an interesting section in Living at superdensity about Odham’s walk (154dph) about which a short film is available from the same website Living at superdensity film
This is what Alex Ely of MAE has to say about housing density:-
To build below 30 dwellings per ha you have to plan pretty inefficiently. The garden cities comfortably achieve densities of 30-40dph; Victorian terraces between 60-80dph; and the Abercrombie Plan around 62dph. Importantly, they all accommodate generous family housing.
“It’s a myth that high density means high rise,” insists Alex Ely, housing co-ordinator of the Commission for Architecture and the Built Environment. Indeed, some of London’s plushest neighbourhoods are built to a classic high density design – three- or fourstorey terracing overlooking private squares . . .
. . . High density living can also work wonders for the social mix. “We’ve seen in the past the dangers of single tenure estates,” says Ely. “We created gated communities of professionals at the expense of key workers.” But in the leading high density schemes, private and social housing sits side-by-side, impossible to tell apart. “Mixed tenure creates a more diverse community,” says Ely. “Social tenants benefit from high numbers of owner occupiers who have an interest in maintaining the place; and they in turn benefit from their local schools and hospitals being suitably staffed [by their neighbours] . . .
MINIMUM DENSITY NEEDED IN TOWNS
Garden cities are not the answer
[ . . . ]
Much of the buzz and interest that we associate with such cities as Paris, Barcelona — and for that matter Bath, Glasgow and Edinburgh — is produced by the density of habitation into the city centre. The population intensity is sufficient to support a rich mix of activity and services as well as a good public transport system.
Some of the most liveable parts of London, eg South Kensington and Islington, are built at densities of 400 habitable rooms per hectare in four-storey terraces.
[ . . . ]
full letter can be seen in Building Design p.8 22/7/2011
[ . . . ]
“I absolutely love being here just because it is so crowded, it is a real city situation although it’s town sized. For instance this row of shops simply wouldn’t exist except that we’ve got such a concentration of population living around here that it supports this many stores.”
“We’ve got stores for absolutely every purpose one really doesn’t have to shop further than just round and back of the house this way. There are liquor stores, there’s a cake shop, you can buy meat pies, there’s a marvellous Post Office that has absolutely everything. It’s more like the old fashioned General Store that they had in small villages in America which really served the community completely.”
[ . . . ]
Mitzi Cunliffe – Sculptor
I Love This Dirty Town – BBC 1969
HIGH DENSITY SCHEMES THAT DON’T WORK
This is all very well when they’re done with care and after all Odham’s Walk is nearly 30 years old and was designed and built in the days of the GLC. Architects had public money to spend on housing then combined with supportive government. Now the volume house builders will stick up any old rubbish providing somebody will buy it, have a browse around the rest of my blog. In 1981 the GLC still had its own architects’ department. Now (2010) there are few public authorities left with their own architects’ departments.
This don’t care attitude combined with a lack of regulation, the need for high density living and “if we build it they’ll buy it” mentality is what has resulted in modern slums that are single aspect flats and multi-storey terraced houses with one external door. I make no apology for saying this. Not for many decades has housing faced such a crisis of quality and the only saving grace is that with the cuts being made and about to be made a lot of the rubbish already past planning simply won’t be built in its present form.