Using algorithms to analyse the visual properties of a building's style

Residential development within heritage conservation areas is regulated by Development Control Plans (DCP) that provide guidelines about the shape and form that new houses, alterations and additions should take (DIPNR 2004). By understanding that the visual amenity of streets within a city plays an important role in creating a sense of place and community for its citizens (Lynch 1960) they attempt to sustain, through regulation, an urban pattern that has become valued by the community. The visual character of a building within a streetscape is often associated with the style of its construction - a set of visual characteristics that a group of buildings might share. These characteristics include the relationship of the parts of the building to each other, and to the building as a whole, the use of ornament and visible textures, and the scale of elements within the composition. Using algorithms developed within robotic research that enable a computer to interpret a visual environment (similar to those used in medicine and facial recognition for instance), this paper outlines how algorithms can be used to study the visual properties of the built environment. One of the methodological qualities of computer visualisation that makes it so useful for a comparative visual analysis of buildings is that the representational and symbolic meanings of a buildings style play no part. The organisation of the elements can be analysed without having to interpret their possible meaning at the beginning of the process. This paper builds on an established interdisciplinary approach, utilising architectural knowledge and computer visualisation to evaluate the visual character of detached housing within a heritage conservation area. The visual environment is analysed using computer software developed to locate the visual boundaries within a view of a streetscape both as an elevation and aerial view.