Figure-Ground Analysis
Also known as: Solid-Void Analysis, Nolli Map Analysis, Poché Mapping, Built-Mass and Open-Space Analysis
Figure-ground analysis is an urban-design technique that maps a city as a pattern of solids and voids — buildings rendered as black figure against the white ground of streets, squares, and open space (or vice versa) — to reveal the structure, density, and spatial quality of the urban fabric. Descended from Giambattista Nolli's 1748 map of Rome, it makes legible the relationship between built mass and open space that ordinary plans obscure. Roger Trancik's 1986 Finding Lost Space established it as a core method of contemporary urban-design theory, arguing that good cities are defined as much by the shape of their voids as by their buildings.
Key highlights
- Makes the otherwise invisible solid–void structure of urban fabric immediately legible at a glance.
- Treats open space as positive, shaped form, directly supporting public-space and enclosure judgements.
- Yields simple, comparable measures — coverage ratio and grain — across districts, cities, and design options.
- Bridges qualitative design reading and quantitative morphology from a single, low-data diagram.
Intuition
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How it works
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When to use it
Use figure-ground analysis when you want to read and compare the spatial structure of urban fabric — at the scale of a district, neighbourhood, or design site — and especially to evaluate the quality of public space and the relationship between buildings and the spaces they shape. It is a staple of urban-design diagnosis, masterplanning, and morphological comparison across cities or eras. It is less suited to questions that hinge on building height, use, or three-dimensional form, since the plan-based diagram is inherently two-dimensional, and it can mislead if footprints are incomplete or if the binary abstraction discards distinctions (public vs. private open space) that matter for the analysis at hand.
Strengths & limitations
- Makes the otherwise invisible solid–void structure of urban fabric immediately legible at a glance.
- Treats open space as positive, shaped form, directly supporting public-space and enclosure judgements.
- Yields simple, comparable measures — coverage ratio and grain — across districts, cities, and design options.
- Bridges qualitative design reading and quantitative morphology from a single, low-data diagram.
- Purely two-dimensional: it ignores building height, volume, and the third dimension of urban form.
- The binary solid–void abstraction discards land use, ownership, and public/private distinctions among voids.
- Results depend on the completeness and accuracy of footprint data and on the chosen extent and scale.
- Pattern interpretation is partly subjective and can vary between analysts reading the same diagram.
Common pitfalls
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Applications
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Frequently asked
What is a Nolli map and how does it relate to figure-ground?
A Nolli map is the 1748 plan of Rome by Giambattista Nolli that rendered the city as solid (built mass) and void (open, accessible space). Its distinctive move was to treat publicly accessible interiors — the naves of churches, colonnades, covered passages — as part of the white 'void' rather than the black 'solid', so the map shows the full continuous network of space the public can occupy. Figure-ground analysis generalises this idea: any solid–void diagram that abstracts a city into built figure and open ground is a figure-ground study, and the Nolli treatment of interiors is one refined variant of it.
What does the 'grain' of urban fabric mean?
Grain refers to the characteristic size and granularity of the building and block pattern. A fine-grained fabric has many small blocks, narrow plots, and frequent street intersections, which tends to support walkability, permeability, and a mix of uses; a coarse-grained fabric has large blocks, superblocks, or megastructures with few connections, which tends to reduce permeability. Measuring mean block or parcel size and the regularity of the pattern lets analysts compare grain across places, and it is one of the most informative quantities a figure-ground diagram yields.
Why is figure-ground considered a two-dimensional limitation?
The diagram is a plan: it shows where mass and space sit on the ground but says nothing about how tall buildings are or how much volume they enclose. Two fabrics with identical figure-ground patterns can differ enormously in built density, sunlight, and three-dimensional character — a district of two-storey terraces and one of twenty-storey towers can read the same in plan. That is why figure-ground is usually paired with section-based or volumetric methods (and with sky-view-factor or urban-canyon analysis) when the third dimension matters.
Sources
- 1.Trancik, R. (1986). Finding Lost Space: Theories of Urban Design. Wiley.ISBN 9780471289562
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Cite this page
ScholarGate. (2026, June 22). Figure-Ground Analysis. ScholarGate. https://scholargate.app/urban-studies/figure-ground-analysis