Go Figure: Figure-ground as a Land Use/Transportation ToolJuly 28, 2010 by: Gary Okerlund
It has long been widely recognized by many city planners, urban designers, architects, landscape architects, and historic preservationists, that, among many other influences, a viable community has a balanced relationship between building mass and open space that gives it a sense of compactness, spatial definition, and is in human scale.
This concern is even more relevant presently, where the concept of transit-oriented-development, is receiving more currency in the light of increased public dissatisfaction with characterless, auto-oriented, suburban sprawl, and the recognition that transportation choices and land use choices are inextricably intertwined. This put transportation planners and urban designers at the same table and figure-ground is a mutually important working concept at this table.
Simply, a figure-ground, sometimes referred to as figure-field, it is a diagrammatic abstraction of the footprint of the build form of an area, building footprints shown in black for instance, and remaining open spaces in white. It is generally devoid of other detail that can confuse or obscure the spatial nature being examined.
The quality of the physical form and pattern of a community is influenced by the ratio of building mass (forms) and voids (open spaces). When the ratio of building mass is high in relation to exterior space, spatial continuity in the form of building mass and clearly defined “walls”, well defined linkages, and articulated public and private spaces, are possible. These are the characteristics of memorable places with vibrant, mixed-use activity that are attractive to people.
When the ratio of building coverage is low and disconnected in relation to that of exterior spaces, there is often little building mass continuity, emphasizing free-standing, disconnected and fragmented buildings. In between there are undefined voids like surface parking with little spatial definition. Anyone who has ever been unfortunate enough to walk along a major suburban artery knows these conditions of auto-oriented strip development are unfriendly to pedestrians.
The employment of a figure-ground diagram has a long history. Probably one of the most famous uses of the figure-ground as an illustrative tool is the Nolli Map of Rome prepared by Giambattista Nolli in 1748, a portion of which is shown below. The map shows public and private spaces carved from the mass of building form that is so characteristic of the urban qualities that exemplify Rome. It has influenced architects and urban designers since. The figure-ground diagram of the Piazza Del Campo in Siena, Italy also makes clear the distinctive spatial pattern of spaces, narrow network of streets, and fluid geometry, of a typical medieval city.
What a figure-ground is and isn’t.
A figure ground can be a useful analysis tool. One can quickly and unblinkingly assess the potential of a place; does it have the spatial qualities to make it appealing and vital for people and pedestrians – or does it not?
It can also be used as a quick and flexible planning and design tool, allowing one to examine, and verify during the design process, whether the spatial qualities desired are being met or not. It can be employed in sketch format during design deliberations as shown below, or more formally displayed. It does not replace intuitive design creativity or solid rational deliberations, but can supplement these skills and bridge differences with a common vocabulary.
It is also a useful communication tool because it can diagrammatically show the importance of spatial form and space in any proposal that is generally understandable to the public.
To illustrate, the following example shows an air-photo of an underdeveloped, auto-oriented, urban corridor, a figure-ground of its existing pattern, a figure-ground proposal that encourages higher densities, building continuity, pedestrian linkages, and responds with densities that can support transit.
A figure-ground is, however, only one tool in the arsenal of planning and design and there are some limitations. It does not, for instance, replace a fully developed plan, thus orientation can be problematical; it also does not express the influence of building heights and topography well, nor articulate differing uses and activities. Figure-ground does not directly reflect the influences of transportation choices and the pedestrian environment, nor reflect the quality of design that is so important to support vibrant communities. It should be used in conjunction with many other tools such as floor area ratio (FAR), zoning, form-based zoning, density and ridership projections, etc. But figure-ground can be very useful as a supplemental ”shorthand” working tool, especially for demonstrating in public meetings or to elected officials how new development will fit in the built environment.
A figure-ground diagram can highlight positive visual characteristics, and conversely those that are negative in a way that can predict the quality of the environment being transformed. It can also be a useful tool to help put land use planners, designers, and transportation planners on the same page.