Living Patterns and the Principle of Concavity

In the next installment of this series by Nikos A. Salingaros, we see how the shape of our spaces, both public and private, can help reduce anxiety.

Interior of the Café Landtmann in Vienna, a favorite hangout of both Gustav Mahler and Sigmund Freud, a wonderful space for creative conversations.

Image credit: Nikos A. Salingaros

A well-designed space offers psychological “reassurance” to us, its users. We find such healthy characteristics predominantly in traditional places. Of course, we can perform an action in any volume barely large enough to contain it. But it should be our goal to design spaces that make us comfortable enough to enact our roles in life without feeling anxiety caused by strict geometry. A successful space, then, is shaped in such a way that it “reassures” our body and mind — not necessarily with its aesthetics, but the medical/psychological response it elicits.

We have all experienced the sense of emotional elation inside a truly great space. That elation has little to do with the room’s size. Yet many Modernist architects seem strangely uninterested in the factors that are responsible for this effect. But we have evidence that the rules for designing such spaces can be discovered, and then tested. Some environments possessing modest dimensions invite us to linger there, yet other spaces of similar shape and size somehow disturb us. Some geometric components and features, which we might not notice until they are brought to our attention, make all the difference in the world to the adaptive quality of spaces that contain human activity.

Spaces that nourish human emotions with built geometries can be documented as living patterns (Alexander et al., 1977), but much of this research remains to be done. Architects trained in conventional methods tend to resist design solutions that employ living patterns. Why? Mostly because they tend to value appearance above utility. They don’t want to be told that their designs might displease or even hurt users’ sensibilities. That would imply failure.  So they ignore feedback and insist on judging design exclusively by abstract aesthetics. For them, design patterns are anathema.

Space is experienced as positive when it is coherent

We find spaces that embrace us gently inviting. Such spaces, formed from concave boundaries, embody the “principle of concavity,” which tells us that we prefer surfaces that enclose us in a more or less organic manner.

Experiments in psychology document that we have a built-in aversion to sharp objects, especially to those that point at us. Most of us prefer rounded moldings to angular moldings in window frames and sills. At the next architectural scale, walls that are not vertical and ceilings that are neither symmetric nor horizontal, and re-entrant walls and ceilings bulging towards us instead of yielding outward cause alarm. Emotional discomfort can be triggered by protruding design details meant for purely aesthetic effect — undoing real or apparent structural utility of elements such as columns, pilasters, or beams.

If we are to use urban space with pleasure and make us feel reassured, it must be partly surrounded by an enveloping perimeter. It cannot just be leftover space between stand-alone “look-at-me” buildings. In those leftover spaces, we tend to feel exposed and threatened because the nodes and paths they contain are not defined coherently (Alexander et al., 1977: Pattern 106; Salingaros, 2005: Chapter 2). Such exterior space lacks internal connectivity and fails to fit into the expectations formed by our instinctive judgment of space. This expectation is built up over generations, passed down to us by previous users of the built environment as well originate in our own experiences.

Many showcase 20th and early 21st Century buildings tend to be surrounded by lots of open space that is never used. Hard plazas and green areas designed around the buildings violate all the living patterns for urban space; therefore those areas tend to be unpopulated, hence they are wasted spaces. Sometimes vast in dimension, these spaces tend to be too open; part of them may be semi-enclosed but threatened by an overhanging roof that creates a feeling of alarm.

For decades, architectural space has been compromised by mistaken assumptions (anti-patterns). Furthermore, the industrialized world continues to create formally striking places that skimp on essential human values. Whether cramped, splintered, or so vast as to engulf human scale, those environments are ultimately useless. The proper connected intimacy of space, offering the psychological protection essential for inviting people to use it, is absent.

Urban space is not two-dimensional. It is not simply a ground plan. Additional geometrical elements are needed to complete the sense of a three-dimensional enveloping boundary. Those elements work in the vertical dimension, and arise from the scales of architecture, not urbanism. Much depends on whether the details of the surrounding walls transmit messages that are either psychologically friendly or hostile to those who visit the open space. Mirrored or transparent curtain-wall façades diminish the visual sense of enclosure of a public space, making it less informative, less interesting, less friendly, less functional. On the other hand permeable solid façades showing organized complexity (as defined by their aligned symmetric doors, windows, and other details) improve the functionality of an urban space.

The humanity — and consequently the frequency of use — of urban space depend upon the user’s experience of organized complexity on the surrounding façades

Image credit: Nikos A. Salingaros

Like a framed picture, every useful and satisfying urban space reaches visual completion at a certain height off the ground. A roof cornice, for example, on facing buildings adds a horizontal lip to the built perimeter of urban space, creating a degree of concavity that enhances the feeling of enclosure (Salingaros, 2005: Chapter 2). Yet such framing edges are dismissed as inessential because their original function is not understood; yet they play a major supportive role in the definition of reassuring urban space through the principle of concavity.

In Volume 3 of The Nature of Order (2005) Christopher Alexander introduces the concept of “hulls” (as in the concave hull of a boat) in public space. This reinforces the idea of coherent public space that promotes the sensation of being in a giant outdoor room, a room without a ceiling. Alexander also describes the process of designing indoor rooms whose volume and boundaries offer the qualities necessary to induce psychological wellbeing. Altogether, we possess a set of powerful tools for creating coherent living space, interior or exterior, defined by the characteristics of its enveloping and sheltering boundary.

Living patterns enhance our lives and health

Humans have used patterns for millennia, extending biology to shape the built environment. But living patterns as studied relationships among design elements may seem irrelevant when interpreted, as they often are, in the framework of a purely formal, sculptural architecture.

Living patterns have immediate consequences for human health and life. They are not simply a matter of individual preference. The relationships embodied in living patterns help create an environment with healing properties. Faster healing after surgery, for instance, depends on exposure to natural environments, and buildings that have the right mathematical qualities mimic this effect. The backstory became evident with research on the concept of biophilia and evidence-based design that arose from it (Browning et al., 2014; Kellert et al., 2008; Mehaffy & Salingaros, 2015: Chapters 11 & 12; Ryan et al., 2014; Salingaros, 2015). Patterns not directly linked to biology may still be interactive or social, acting together on different scales in a way that mimics nature.

To read the design framework of 253 socio-geometric patterns (Alexander et al., 1977), is to immediately feel the patterns, especially the biophilic ones, to be true in a visceral sense. Living patterns make design a more participatory, vernacular, even democratic process, working to push back against the myth of the “genius” (and often authoritarian) architect.

Some patterns rely on experiential psychology, driving humans to feel comfortable instead of uncomfortable in different types of settings. Others relate to our visual and spoken communication with passersby, be these sight lines, proximity, and other factors that promote or discourage interaction. Human contact is required for the wellbeing of adults, and especially, at either end of lifespan, for both the emotional formation of children and emotional health of the elderly.

The pattern format recommends a set of design constraints; relationships that narrow the specific expression of any given design solution. This constraining specificity enables the transmission of such healing knowledge from one culture, historical time and place to another (Salingaros, 2005: Chapter 8).

Patterns are an adaptive design tool— already available, developed previously by someone else. Their documentation saves architects an enormous amount of work. They need not rethink everything to implement a new project. The flexibility of living patterns means that what is re-used is only the most relevant structural relationship, conveyed as an evidence-based proposition. A living pattern does not merely copy an image from the past but implements the latest upgrade. In this sense, living patterns are tools of evolutionary, adaptive design (Leitner, 2015; Mehaffy & Salingaros, 2015: Chapter 18).


Christopher Alexander (2001-2005) The Nature of Order, Books 1-4, Center for Environmental Structure, Berkeley, California. Book 1: The Phenomenon of Life, 2001; Book 2: The Process of Creating Life, 2002; Book 3: A Vision of a Living World, 2005; Book 4: The Luminous Ground, 2004.

Christopher Alexander, S. Ishikawa, M. Silverstein, M. Jacobson, I. Fiksdahl-King & S. Angel (1977) A Pattern Language, Oxford University Press, New York.

William Browning, Catherine Ryan & Joseph Clancy (2014) 14 Patterns of Biophilic Design”, Terrapin Bright Green, New York. Available from: <>

Stephen R. Kellert, Judith Heerwagen & Martin Mador, Editors (2008) Biophilic Design: The Theory, Science and Practice of Bringing Buildings to Life, John Wiley, New York.

Helmut Leitner (2015) Pattern Theory, CreateSpace, Amazon.

Michael W. Mehaffy & Nikos A. Salingaros (2015) Design for a Living Planet: Settlement, Science, and the Human Future, Sustasis Press, Portland, Oregon and Vajra Books, Kathmandu, Nepal.

Catherine O. Ryan, W. D. Browning, J. O. Clancy, S. L. Andrews & N. B. Kallianpurkar (2014) “Biophilic Design Patterns: Emerging Nature-Based Parameters for Health and Well-Being in the Built Environment”, Archnet-IJAR: International Journal of Architectural Research, Volume 8, Issue 2, pages 62-76. Available from: <>

Nikos A. Salingaros (2005) Principles of Urban Structure, Techne Press, Amsterdam, Holland; reprinted 2014, Sustasis Press, Portland, Oregon and Vajra Books, Kathmandu, Nepal.

Nikos A. Salingaros (2015) “Biophilia and Healing Environments”, a 10-part essay series in Metropolis, August–September. Published together as a booklet by Terrapin Bright Green, LLC, New York. Available from: <>

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