Analyzing Architectural Designs for Copyright Disputes

TASA ID: 10524


There’s nothing simple about architectural copyright litigation. Activity generated from The Architectural Works Copyright Protection Act of 1990 continues to increase. The law continues to develop factual realities, though sometimes obvious, are often complex and difficult to compare. What is an architectural work? It is a building design embodied in any tangible medium of expression, including a building itself, architectural plans, or drawings. Overall form is copyrightable. Exterior and interior spatial arrangements and elements of these arrangements are copyrightable. Individual standard features are not copyrightable. These presuppositions raise further questions. 

Substantial similarity is a key condition.  If one work alleged to be a copy of another reaches a threshold condition of substantial similarity, that work could be called a copy. Are all houses of any one type, like a four-three split configuration, so inherently similar that the possibility of copyright infringement is nil? Architects distinguish served from servant spaces. Suppose a house plan with 8 foot ceilings is copied except that three served rooms, LR, DR and MBR have 10 foot ceilings. These three served rooms not only have 25 percent greater volume, they deliver a different experience. Is the alleged copy substantially similar? Should these differences be considered a design improvement that does not reach the threshold of substantial similarity or has this design passed the threshold and is simply super adequate?  


Geometry has long been at the core of architecture. At one time called the science of space (Evans 1995), geometry has become little more than a secondary school subject for most people. Geometry occupied a less abstract world centuries ago. Oblique perspective maps of cities were commonly produced in the late Middle Ages and Renaissance because they are more easily understood than maps showing top-down city plans. Liben (2005) says this is because these maps represent embodied experience. 

What is lacking is an analytic approach, a method that can reliably distinguish one apparently similar building design from another.  This is a geometric problem. For example, any two or more geometric forms can be compared at six levels or conditions of decreasing identity and similarity. Two fully identical geometric forms: 

  1. will be positioned identically in a spatial context; 
  2. will have the same dimensions;
  3. will have the same angles and dimensional proportions;
  4. will have each and all the same or equivalently parallel elements;
  5. will have the same cross-ratios and;
  6. will have all individual elements of the form equally contiguous. 

These must be understood as nests.  Condition 1 includes conditions 2 through 6 (March & Steadman 1971). 

For two apparently similar buildings, condition 1 would require virtually similar settings, something rarely present. Even so, the building would still be identical even if the setting were different. Two apparently similar buildings meeting condition 2 are identical. Two apparently similar buildings, meeting condition 3 could be substantially similar but one might be much smaller or larger than the other, or a scale model. Two apparently similar buildings meeting only conditions 4 through 6 may or may not be substantially similar. If none of these conditions are present, substantial similarity is unlikely. 


Our work on developing a method to represent geometric configurations began in the 1970s as a series of exercises in finding ways to represent spatial patterns. The ambition was to come up with something as different from the squares, rectangles, lines, circles and similar geometric forms that make up an arrangement as Arabic numerals are different from Roman numerals.  We eventually called this the shape-network™ method.  The shape-network™ method decomposes a configuration like a floor plan or elevation into more elementary shapes enabling these shapes and their network relationships to be compared. It enables precise comparative and quantitative analysis of a very wide variety of configurations. It is one of a group or class of approaches that examines architectural and urban form using a combination of discrete geometry (low-dimensional geometry), mathematical network analysis and other approaches like cellular automata. When focused on spatial patterns shown in floor plans, shape-networks™ will represent these patterns as networks of spaces and connections: movement possibilities. When focused on visual patterns that are shown in elevations, the method will identify elementary shapes and patterns that taken together constitute a holistic arrangement. The following plans of early 20th century houses show three different interior and exterior configurations. If you closely examine the letters on each labeled space, you might see similarities. 


A simple shape-network™ representation of contiguity conditions of the three designs shows they are almost identical. The lower one is slightly different because it has one more bedroom. While moving from room to room could be a substantially similar embodied experience, none of the rest of the identity conditions can be satisfied. And none of these designs can be said to be similar. Each house was designed by one architect, Frank Lloyd Wright. 

Each of these configurations can be decomposed further.  Many created spaces have what appear to be irregular patterns that are difficult to capture using conventional geometric approaches. The public space of an enclosed shopping mall, almost always composed of irregular spatial patterns, is an example. Shape networks™ go beneath conventional geometric approaches of spatial measurement by identifying fundamental elements shaping everyday space. Everyday space is formed by physical features of the natural and built environment. It is the space shaped by walls, doors, curb cuts, countertops, partitions, columns, arcades and so on. It can be equivalent to a room or a part of a room. It is perceived tacitly and subjectively and, as it is directly experienced, especially through normal movement, it is not understood in typical geometric terms of length, area and volume.  We use two fundamental shapes that are part of every spatial configuration: straight lines and convex spaces.

Cognitive scientists Edvard Moser, May-Britt Moser and John O’Keefe received Nobel Prizes in 2014 for their research on the neural elements of cognitive mapping. The Mosers showed that 1) when a land animal faces a certain direction, regardless of its position, head direction cells fire, and 2) when an animal is near a wall or an edge, border cells fire. 

Head direction cells give us information as a straight line from A, our position, to B, what we look at. Border cells give us information about barriers that limit our movement from A to B. These shapes bear on  for pedestrian and vehicle movement.

The two illustrations above show an L-shaped space which contains two elementary units called intervals because they are components, intervals, within larger configurations. One is a convex interval – there are two in the L-shaped space. The other is a lineal interval – there is one in the space with one doorway and two in the space with two doorways. These are linked into networks similar to those shown above. A variation on this is applied to elevations and façades.

We have used this approach to describe links between configuration and movement in a variety of cases involving spatial configurations. It has survived Daubert review.



Deciding what is and is not similar is ultimately a judgment task.  As prospect theory has adequately shown, human judgments can be flawed due to the variety of biases and heuristics we use to solve problems. Human recognition abilities vary. There are super recognizers who see a face holistically and those who see the parts, whose ability to recognize a face is poor. What we know about facial recognition appears to apply to the recognition of objects like buildings and their representations. Those who are poor face recognizers may be unable to distinguish important differences in building form. Since recognition is a route to total concept and feel, it is essential to understand precisely what is being recognized.

Sources and Further Reading

Brown, M. Gordon and Charles C. Lee. 2016. From savannas to settlements: exploring cognitive foundations for the design of urban spaces. Frontiers in Psychology, section Cognitive Science. doi: 10.3389/fpsyg.2016.01607.

March, L., and P. Steadman. 1971. The Geometry of Environment: Mathematics and Science in Design.   London: RIBA Publications.

O’Keefe, John and Lynn Nadel, 1978. The Hippocampus as a Cognitive Map. Oxford: Clarendon Press.Solstad T, C. N. Boccara, E. Kropff, M-B. Moser and E. Moser. 2008. “Representation of Geometric Borders in the Entorhinal Cortex.” Science 322: 1865–1868.

Evans, R. 1995. The Projective Cast: Architecture and Its Three Geometries. Cambridge, MA and London: MIT Press. 

Liben, Lynn, and Lauren J. Myers. 2005. “Developmental Changes in Children’s Understanding of Maps: What? When? And How?” In The Emerging Spatial Mind. Edited by Jodie M. Plumert and John P. Spencer. New York: Oxford University Press, pp. 193–218. 

About the Author

The author is principal of Space Analytics ( in Wauconda (Chicago). He has written, consulted and done expert witness work for 30 years on design and the built environment. He developed shape-network™ methodology that transforms spatial patterns into networks and has consulted on major architectural copyright, public forum, access and premises liability cases. He is a member of the honorary land economics society, Lambda Alpha International and Fellow of the Royal Institution of Chartered Surveyors. He was Academic Fellow of the Urban Land Institute, a professor of architecture at three major American universities, head of the Real Estate Program at Eindhoven University of Technology, and the Aldar and academic dean at the Higher Colleges of Technology in the UAE. The expert has a BS from the University of Illinois, Urbana, an MBA from Penn’s Wharton School, MSc (Arch) from University College London and DTech from Ulster University. 

© 2017 

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