As proposals for tall buildings become more prevalent, we look at the changing attitudes in UK planning policy that have made it easier for architects to design skyscrapers.
Not since the 1960s have so many proposals been made for tall buildings. Tall buildings generate such fevered debate because their size and prominence gives them a unique ability to enhance or harm a place. Over the last seven years, virtually every major tall-building proposal in the UK has been referred to CABE for design advice, giving us a good overview of this phenomenon.
Controversial as they remain, tall buildings are undoubtedly finding wider acceptance than in previous decades.
More people now recognise that building tall can be a good way to provide jobs and homes, and recent debates have highlighted some underappreciated benefits. In heritage terms, for example, the relatively small footprint of tall buildings can be better than the much bigger footprint of 'groundscrapers' in maintaining the fine medieval grain of streets in places like the City of London.
The quality of tall-building design is increasingly understood to be the key, and it is 30 St Mary Axe - otherwise known as the Gherkin - that has perhaps done the most to change attitudes in recent years. Using modern modelling and construction techniques, 30 St Mary Axe has redefined what a tall building can look like. It has been a smash hit during Open House weekends, showing that a tall building of first-rate design quality can be extremely popular with the public, as well as working well for its users. And it has shown that tall buildings can have a positive symbolic and civic role, despite usually being private buildings.
The relatively untroubled passage of 30 St Mary Axe through the planning process gave encouragement that good tallbuilding schemes can gain consent. A couple of other high-profile public-inquiry decisions in favour of tall-building schemes have given similar encouragement and raised some interesting points.
In the case of the Heron Tower in the City of London, the planning inspector highlighted the importance of how a tower works at street level and relates to neighbouring buildings. And in the case of Shard London Bridge, the Secretary of State stated that the quality of the design was a key reason for approving the scheme.
PLANNING POLICY These factors have helped set the context in which a wave of tall-building proposals can come forward, driven in particular by buoyant demand in the financial sector and the housing market.
The policy context has had to develop to take account of this.
Although there is no separate national policy specifically aimed at tall-building proposals, many planning policy statements are relevant. These include PPS1: Delivering Sustainable Development, and PPS3: Housing - if the building is residential. Two themes that have received increased emphasis in national policy in recent years - the importance of good design and the encouragement of a plan-led approach to planning - are particularly applicable to tall buildings because of their prominence and potential impact.
The challenge for local authorities is to translate national policy into a practical way to deal with complex tall-building proposals. In 2003, CABE and English Heritage set out to help, with their joint 'Guidance on Tall Buildings'. As well as outlining how the two bodies will evaluate such proposals, the guidance is also intended to provide advice for local authorities and to give them a starting point for local policies. The government has said that the joint guidance is capable of being a material consideration in the determination of planning proposals; the evidence suggests it is taken very seriously by local authorities and planning inspectors. And many of the points it makes have now become standard practice - such as the need for an accurate view analysis for all major schemes.
Having a policy framework which is attuned to local circumstances and gives developers certainty about the standard of design and construction expected of them is crucial to ensuring good-quality tall-building proposals, and this is where local authorities come in. The extent to which such policies are in place varies between local authorities. But as planning continues to move towards a more plan-led and proactive system, there will be increasing pressure on those local authorities without policies to put them in place. For many the need is now urgent. This is particularly the case in London, where Mayor Ken Livingstone's London Plan provides a regional framework identifying 'opportunity areas' where intensification of development should occur. Local authorities need to provide the next level of detail.
TRENDS IN TALL-BUILDING DESIGN Tall-building proposals are now just as likely to be put forward in Manchester, Leeds, Birmingham or Liverpool as they are in London, a sign of the economic renaissance of our regional cities - and perhaps also a function of a little civic rivalry. As long as the proposals are subject to public debate, are well designed and based on sound financial calculations, tall buildings can be part of the ongoing success story of these cities.
A greater cause for concern is that tall-building proposals are increasingly coming forward in smaller cities and the suburbs of London. Some of these places simply do not generate the sale or rental value to support the quality of design and construction needed. Building a tower is an immense financial and logistical undertaking, particularly if - as should be the case - the design, materials and detailing are of the high standard required by CABE and English Heritage guidance. Low-quality towers are a real danger in cases where the financial viability is questionable.
There is also the perpetual risk of the 'dumbing down' of designs after planning consent has been granted. Local authorities need to be alive to these considerations. Planners need to set a benchmark for high quality, giving developers certainty about what they need to do, and then accept nothing less than that benchmark.
In the last six years, the types of uses proposed for tall-building schemes have changed significantly. The initial wave of proposals was concentrated in the City of London and proposed new office accommodation only. The Heron Tower, the DIFA Tower, 30 St Mary Axe and the Minerva Building led the way.
As pressure for high-density living has increased and the housing market has sustained remarkably strong growth, more and more residential towers have been proposed. And a growing trend in recent years is for mixed-use towers, reflecting encouragement for this in national policy. Shard London Bridge was an early pioneer of this approach, and the Beetham Tower in Manchester, which has a hotel and private apartments as its major components, is the first major completed example.
One of the principal problems with tall buildings of the past has been the frequent failure to address ground conditions adequately. Disappointingly, this often continues to be the case.
While the appearance of tall buildings on the skyline is clearly important, the interaction that people have with a tall building at street level is at least as significant. Many developments block pedestrian movement and offer little in the way of public space and facilities. The environmental effect of towers also needs to be considered. An excellent tall building should enhance its surrounding area and share the benefits of the investment it represents by providing public access around, through and inside the building. CABE particularly advocates access for the public to the top of tall buildings, so that views can be widely enjoyed.
As with other major developments, the design of tall buildings increasingly has to consider the issue of sustainability.
Their form gives them some advantages in this respect, with good access to sunlight and wind power, and many designs have incorporated solar panels and wind turbines. The all-glass tower is the subject of intense debate about its environmental credentials;
CABE suggests that environmental claims for buildings with glass cladding should be subjected to close scrutiny.
THE FUTURE So where is the tall-building phenomenon heading? The potential benefits of tall buildings seem to be gaining wider recognition.
Demographic and economic pressures in London and the core cities are likely to result in more proposals. And local authorities without a policy will be under increasing pressure to produce one - including authorities hitherto untroubled by tall building schemes.
But forests of skyscrapers in our cities seem unlikely. It's worth bearing in mind that many designs that gain planning permission will never be built. Beginning construction is a major commitment, since costs are large and only building part of the scheme isn't an option. It's not surprising, then, that of the proposals seen by CABE in recent years, few have been built or have a firm start date for construction. And if local authorities establish robust policies and take advantage of the design advice available to them, poorly designed proposals should be refused planning permission.
A limited number of tall buildings - most of them well designed and leaving a better overall legacy than in the '60s - seems the most likely outcome of the current flurry of proposals.