The role of tall buildings in achieving high densities in residential areas; the provision of offices for certain types of global companies and as a means of enhancing the beauty of our cities

  Oxford has a tight green belt, which restricts land supply. This has resulted in efficient use of the existing land available for development through infilling, raising densities and use of previously developed sites. Prior to the publication of PPG3, the average residential density in Oxford was 54 dwellings per acre (higher than most shires). Post PPG3 (March 2000) much higher densities have been achieved through good design and lower car parking standards, as most sites have good access to public transport. This approach to raising densities has been adopted in preference to the erection of tall buildings.

  Global companies are generally attracted to major cities and financial centres rather than cities such as Oxford. Whilst Oxford is an attractive historic town, its economy is based on higher education, hospitals, local government, in addition to its traditional manufacturing base, and most businesses are related to these core activities. Oxford also attracts large numbers of visitors, as it is also a good sub-regional shopping centre and tourist centre. In essence therefore, Oxford is a successful employment centre for the City, County and surrounding region without global companies or tall buildings.

  Suggestions that tall buildings are necessary for future economic prosperity should be treated with caution. Tall buildings can undoubtedly fulfil an important role in accommodating office-orientated businesses and other service-sector activities, but they would need to have the advantage of congestion-free transport infrastructure and broad-band ICT infrastructure. This is less appropriate for a historic city like Oxford, but might be located in outer parts of the City, for instance, the Oxford Science Park, if planning criteria allowed. Indeed the Council is keen to maximise the use of its science and business parks in its economic development and job creation.

  Oxford has not encouraged tall buildings as the conservation of the character of the City has long been identified as one of the main objectives of planning policy in Oxford. In particular, the relationship between the built up area of the City, and the open spaces in and around it, makes a major contribution to this character.

The sustainability of tall buildings, in particular in terms of construction, transport and long term flexibility of use

  Sustainable design should introduce economic benefits in terms of cost saving in materials, energy and water use. The cost effectiveness of good design can go far beyond these tangible factors. However, any tall building proposal should be examined for its sustainability in the widest sense, by considering its economic and social impact, based upon whole life costs and benefits.

  In the past there have been many problems associated with the construction of tall buildings, the most fundamental being the materials chosen for the frame, the cladding, and the particular systems of construction. These have given rise to a considerable number of building defects, which in some instances have become chronic through lack of available finance to put them right. The cost of repair and maintenance is directly proportional to the initial cost of construction, and where this is applied to a poorly built tall building, the running costs, and consequently the sustainability, become questionable. There have been too many bad examples of unsuitably sited, poorly designed and detailed, badly constructed and/or incompetently managed tall buildings.

  It is also the case that the design and construction of innovative tall buildings push out the frontiers of building and environmental technology. This may also lead us to think that in the right place, a sustainably designed tall building can contribute positively to city life, in particular by facilitating higher densities. However, good practice suggests that office buildings are best kept at heights of three or four storeys, as this generally gives the best trade off between heat losses through the roof and floor, which decrease with more floors and usage of lift and other mechanical services.

  In residential settings, tall buildings may not give the increased density that they are intended for. Traditionally they are surrounded by vast areas of ill-planned open space, while the increase in car ownership, and the consequent need for parking, can off-set the saving in land take up.

  The regulatory changes to take account of the concerns raised since September 2001 will make building design more difficult and more expensive. In particular attention will need to be given to areas vulnerable to bombs such as underground car parks and basements below tall buildings. The current review of Part A of the building regulations needs to take on board amendments to the rules, and exceptions on progressive collapse of tall buildings, which at present give no differentiation between five and fifty storey buildings. Other design issues involving the spread of fire and evacuation procedures, will also need attention.

  With regard to long term flexibility of use, refurbishment costs are high for tall buildings, whether they be for changing offices to housing or housing to student accommodation, and are substantially higher than the cost of refurbishing low-rise developments. Research also suggests that the cost of demolition currently stands at one tenth of the cost of refurbishing a tall building. Again in terms of sustainability, it would be necessary to assess rigorously at design stage whether a future refurbishment would be viable.

Where tall buildings should be located, including: what restrictions, if any, should be placed on the location of tall buildings, and how far they should be allowed to block existing views; and whether they should be clustered or dotted

  Oxford's Local Plan has had a long-standing strong and effective policy on controlling the heights of buildings (see Appendix A).[23]22 The aims of the policies are to protect the views in and out of Oxford (green backcloth) as well as protecting the historic skyline. Generally, Oxford does not permit any tall buildings, either within the central core of the city, or which would detract from the green backcloth of views from within the city. I would not anticipate any change from the Local Plan policies as a result of the current review.

  Due to the importance of Oxford's architectural heritage, reflected in the concentration of the Colleges in the City centre, the introduction of any tall buildings would seriously diminish its impact and attraction and obscure Oxford's existing beautiful skyline of spires. Because the Local Plan policies on controlling tall building has been so successful, the introduction of almost any tall buildings would now be starkly detrimental to the character of Oxford.

  In general planning terms, the location of tall buildings and blocking existing views, would largely depend on the merit of an individual case. This would need to be assessed through an analysis of the physical, social and economic impact. In general there is a preference for clustering tall buildings, as this would support the provision of good centralised transport infrastructure, services and facilities for the occupants and visitors to tall buildings.

Whether in the present movement to erect tall buildings we are in danger of repeating the mistakes of the 1960s

  No, planning now emphasizes mixed land uses which applies to tall buildings. Unlike the 1960s, when single residential or office uses dominated, the current preference for a mix of uses will create more sustainable environments for people to live, work and play in.

  We are assuming that this is a reference to tall residential blocks. From the Council's perspective as a social landlord, there is unlikely to be any movement back towards the construction of tall buildings. Leaving aside the social lessons learnt, the capital costs of tall buildings is prohibitive and has been driven further up by tighter building regulations, to ensure increased safety. Oxford has a need for additional social housing, however, the shortage lies in three-bed or larger family units and not the one or two-bed flats associated with the tower block structure.

  Tower blocks have been associated with anti-social behaviour problems, sometimes as a result of concentrating families/tenants with problems in one area or block. Noise nuisance and vandalism of the communal areas are well documented issues. Therefore the City Council would prefer to see low rise developments, albeit with layouts to ensure sufficiently high densities.

Whether those making decisions are sufficiently accountable to the public

  Planning legislation, development plan procedures and consideration of planning applications, which are functions of democratically elected councils, all ensure that the public are involved and consulted on all types of planning decisions. Oxford City Council has just adopted its new modernised political structures, which include a Cabinet and five area committees. These have small budgets and delegated authority for some decision-making, including relevant planning applications. This is intended to ensure the maximum opportunity for local people to be involved in both observing the decision-making process and contributing to the planning debate.

Whether the Government should have a more explicit policy on the subject

  Apart from the appropriate guidance in PPGs and controls through Building Regulations, I think it would be unhelpful to impose explicit and prescriptive policy on the subject. Tall buildings may still have a role in the management of sustainable development in a small island. However, a set of approved criteria for assessing the impact of tall buildings could be useful guidance, possibly on similar lines to the EIAs.

  If appropriate controls are enforced through the existing statutory planning and building control systems, they can be relied on the limit any potential negative impact of this form of development. However, there may be a case for the tightening of regulations for the erection of tall buildings, through extending the requirement to carry out risk assessment and the provision of security measures. This could run alongside the existing regulations and the safety nets provided by BREEAM.