BCD 2019

PROFESSIONAL SERVICES 1 35 C AT H E D R A L C O MM U N I C AT I O N S T H E B U I L D I N G C O N S E R VAT I O N D I R E C T O R Y 2 0 1 9 introduces stricter planning controls which acknowledge that the accumulation of seemingly innocuous small alterations and more obviously, new development, can harm the special character of a conservation area. Just as those planning controls allow planning officers to require homeowners in conservation areas to use high-quality materials for new features (such as windows), they also require developers to put forward high-quality designs for new buildings in conservation areas. Where these controls are improperly enforced, conservation areas can be quickly devalued through negative change, damage and neglect, and become at risk. To combat this, there are powers in place that allow local authorities to help prevent neglect and damage, but arguably good new design is one of our greatest tools to ensure that the special character and appearance of conservation areas is protected. Urban conservation areas are currently experiencing a rate of change which could see many of them irreparably altered. The reasons for the high rate of change are manifold but ultimately the presumption in favour of sustainable development by governments is the driver. Each of the four home nations has some form of national planning framework and across them all the push for sustainable development is the overarching common principle. Sustainable development is defined in the Brundtland Report as the process of improving the economic, social and environmental well-being of the country to meet the needs of the present, without compromising the ability of future generations to meet their own needs. Just because an area is historic or has a character or appearance that makes it special, it doesn’t mean it is exempt from this presumption for new development. To take England as an example, to meet the current needs for housing and new development, the National Planning Policy Framework 2018 directs local planning authorities to look for opportunities for new development within conservation areas. Not all conservation areas are no-gos for development. Many of our urban areas, and by extension many of our conservation areas, have been blighted by poorly designed buildings and developments that detract from the character of places by creating gaps or monoliths in the topography of our streetscapes, negatively impacting the way we experience them. Today, arguably, those sites represent opportunities for redevelopment and perhaps larger urban regeneration projects. In order not to repeat the mistakes of the past we must approach those sites with a set of principles which aim to improve that area, and in the case of sites within conservation areas, new development must also preserve the areas’ unique importance. In order to preserve and improve an urban conservation area through new development, both its historic importance and its communal value and functionality must be assessed and understood. Pinpointing the significance of a conservation area is a difficult task, but to get a clear picture of an area’s importance the assessment of it should explore the relative value of the elements and buildings which make up the area, and the sequence of change to the area over time. Once the importance of the conservation area and the buildings within it have been understood, this knowledge should underpin and inform the design of a new development. To improve an area, designers must assess the strengths and weaknesses of the way an area functions. Successful streets, towns and cities have characteristics in common and these factors have been used to form the objectives of urban design. Broadly, those objectives are: that new development should seek to create a place with its own identity; that private and public spaces are distinguishable from each other and open spaces are successful; that a place that is easy to understand and adaptable, and where amenity is diverse. These objectives take into account the fact that whether or not we can articulate why badly designed areas and buildings don’t work, we will have a negative experience of those places. For this reason, not only does good new design come from understanding a place, which is crucial to protecting the historic and aesthetic importance of conservation areas, it also has the value of enlivening it and having a real impact on the way a community feels about its area. Good design results from consideration being given to a broad range of concerns relating to the form of new buildings, structures and spaces. Form is the physical expression of urban design and the following considerations will influence a new building’s form. PROPORTION, SCALE AND HIERARCHY In order to respond well to its context, a new development should consider and complement the prevailing townscape of a conservation area. This includes taking account of and responding to distinctive local building forms and the historic pattern of development in the area. The relationship between the height of buildings and the streets they flank and enclose is of critical importance to maintaining the character of urban conservation areas. A common characteristic of successful new design in urban conservation areas is its attention to human scale. Developments which are overbearing and starve the street of light and air can have a substantially detrimental impact on urban streetscapes because we feel uncomfortable and overwhelmed within them. As a general rule the scale of a new building should relate to the width of the street it occupies. Another general principle to consider is that new buildings should respect the height of the surrounding area. This does not necessarily mean that all new buildings in conservation areas should be smaller in scale to the existing buildings: subservience isn’t always the correct design approach. For example, some urban townscapes may benefit from a landmark building on a vacant site that takes its cue from the surrounding area and stitches it back together. The appropriateness of this approach will depend on the hierarchy of the existing buildings and their massing and proportions, although there is generally more scope for change to heights and rooflines in streets where there is a variety of building heights and frontages. In the case of conservation areas which are designated for the uniformity of design of the buildings Located within the Maritime Greenwich World Heritage Site, the proposed design for the Stockwell Street Library at Greenwich University was considered insufficiently traditional by UNESCO’s World Heritage Committee. The design was adapted and a fine grain approach was adopted, reflecting the scale and massing of its urban surroundings. (Photo: Hufton & Crow for Heneghan Peng Architects)