Mayor Boris Johnson has clear aspirations for London to become 'the best big city on earth'. Whether this is achieved or not, its size is beyond doubt and growing fast, with the population expected to rise by up to a million above its current 8.2 million residents by 2031. This growth is accompanied by demographic change — later marriage, fewer children, more divorce and longer lives — driving up demand for new homes and resulting in overall household growth which outstrips the population growth rate. London's draft Housing Strategy identifies that of the 750 to 850 thousand additional households the city will have by then, almost three-quarters will be single-person households.
As demand outstrips supply, house prices and rental values are rising rapidly and properties are becoming increasingly overcrowded and unaffordable. To keep up, the Greater London Authority (GLA) anticipates that an additional 32,600 homes will need to be built every year. When, where and whether these come forward remain to be seen. London is surrounded by a tight greenbelt, protected open land that defines the city's edge and, effectively, its growth. The global financial crisis has also forced a reassessment of many schemes no longer viable in the current market. Furthermore the planning process is detailed, time consuming and not without risk, delaying the speed at which developers can respond to need. This combination of restriction, return and risk points towards one potential response: densification. But is 'vertical living' the right way to address the city's housing crisis?
High rise living is becoming an attractive option, as people increasingly wish to live closer to their place of work and are content to forgo the amenities of low density living. London has become a key destination in the global property market and high rise is popular with foreign investors.
Rising above the stigma
Heavily populated cities such as Tokyo, New York and Shanghai are constantly adapting through increased densification of their city cores, developing distinctive high rise mixed use schemes, such as Tokyo's Mid Town and Roppongi Hills. London has secured only relatively low density development despite the considerable pressures of the housing shortage and changing population.
The aversion to high rise living in London has historical roots. Planning regulations have constrained development. Conservation Areas have existed since the 1960s, preserving the character and appearance of much of Central London. City-wide policies restrict the location of tall buildings, for example through the protection of key views such as those towards St Paul's Cathedral and the Tower of London.
There is also a social and cultural barrier to be overcome. High rise social housing tower blocks built during the 1950s and 1960s to replace poor quality prewar housing stock became vastly unpopular. Particularly from the 1980s onwards these developments became associated with social problems, resulting in stigma and reduced desirability.
The trend nonetheless appears to be reversing. High rise living is becoming an attractive option, as people increasingly wish to live closer to their place of work and are content to forgo the amenities of low density living. London has become a key destination in the global property market and high rise is popular with foreign investors. It is also a product planners are increasingly open to. London's first elected Mayor, Ken Livingstone, actively supported the architect Richard Rogers' concept of the 'compact city', resulting in a number of tall buildings being approved. This includes the 310-metre Shard designed by Renzo Piano which opened to much spectacle this month. There is also the 148-metre Strata SE1 at Elephant and Castle and soon the 181-metre St George Wharf Tower in Vauxhall. Existing buildings are also being transformed through changes of use, such as King's Reach Tower in Southwark, whose retrofit includes 173 residential units.
New policies, new politics
It is recognised however that tall buildings are not appropriate across the whole city. The London Plan of 2011 set out a 'housing density matrix' for different areas. This uses pubic transport accessibility levels (PTAL) and an understanding of context and predominant housing types to arrive at an indicative appropriate density range for each area — measured in both habitable rooms per hectare and dwelling units per hectare (dph) — with the intention that 95 per cent of new developments lie within their identified range.
Density delivers homes and communities, though the way it's done also puts community cohesion at risk, by impacting the overall mix of supply and changing the character of the city.
Livingstone introduced this tool to promote a high density agenda for London, which was achieving incredibly low density compared to, say, parts of inner Paris (300dph) and central Barcelona (500 dph). It appears to have worked: the London average has increased from 59 dph in 1999-2002 to 145 dph in 2007-08. Between April 2006 and September 2007, 513 schemes exceeded the maximum indicative density of 435 dph, and some go higher still, such as Woburn Place in Camden at 2,462 dph, as Duncan Bowie writes in Politics, Planning and Homes in a World City.
Underpinning the density debate is the politics of compromise. Dollar Bay in Canary Wharf, a 31-storey luxury tower providing 111 high specification apartments, was granted planning permission in part because it contributed 51% of the area of the scheme towards affordable housing. The reason it could achieve this, however, was because it was provided off-site, with the majority of its 59 affordable housing units approximately one mile away. Many schemes don't even identify a site, simply providing funds towards a local authority's affordable housing budget; King's Reach Tower contributed approximately 22 million pounds, for example.
It's in the mayor's hands now
London has some way to go to meet the housing demands of its diverse population. Density delivers homes and communities, though the way it's done also puts community cohesion at risk, by impacting the overall mix of supply and changing the character of the city.
Perhaps the greatest opportunity lies with the public sector. The recent passing of responsibility and finance from the Homes and Communities Agency in London to the Mayor means he is now responsible for key development sites like the Greenwich Peninsula and Olympic Park. This places the strategic place-making functions and delivery mechanisms under simple leadership, potentially creating a real opportunity to deliver the correct balance to communities across the city.
Yet, weakened by recession and faced with lingering support for low-rise development, it remains to be seen whether this can be delivered. High density developments may lack the political will required to proceed quickly and overcome tension between local boroughs and the Mayor's office. But given that there is no clear response to the city's housing crisis, vertical living appears to hold the key.
Planning is, however, not only about 'units' but 'homes', the building blocks of communities. We will see exactly how far we are prepared to compromise, but it is more than likely that more deprived parts of the city will have a far weaker hand to exploit as they seek to negotiate their future growth.