A Pattern Language

Written in the 1970s at the University of California, Berkeley, A Pattern Language is structured as a network, where each pattern may have a statement referenced to another pattern by placing that pattern's number in brackets, for example: (12) means go to the Community of 7,000 pattern. In this way, it is structured as a hypertext.

It includes 253 patterns, such as Community of 7000 (Pattern 12) given a treatment over several pages; page 71 states: "Individuals have no effective voice in any community of more than 5,000–10,000 persons." It is written as a set of problems and documented solutions.

According to Alexander & team, the work originated from an observation

At the core […] is the idea people should design their homes, streets, and communities. This idea […] comes from the observation most of the wonderful places of the world were not made by architects, but by the people.

— Christopher Alexander et al., A Pattern Language, front bookflap

The book uses words to describe patterns, supported by drawings, photographs, and charts. It describes exact methods for constructing practical, safe, and attractive designs at every scale, from entire regions, through cities, neighborhoods, gardens, buildings, rooms, built-in furniture, and fixtures down to the level of doorknobs. The patterns are regarded by the authors not as infallible, but as hypotheses:

[…] each pattern represents our current best guess as to what arrangement of the physical environment will work to solve the problem presented. The empirical questions center on the problem—does it occur and is it felt in the way we describe it?—and the solution—does the arrangement we propose solve the problem? And the asterisks represent our degree of faith in these hypotheses. But of course, no matter what the asterisks say, the patterns are still hypotheses, all 253 of them—and are, therefore, all tentative, all free to evolve under the impact of new experience and observation.

— Christopher Alexander et al., A Pattern Language, p. xv

Some patterns focus on materials, noting some ancient systems, such as concrete, during adaption by modern technology, may become one of the best future materials:

We believe ultra-lightweight concrete is one of the most fundamental bulk materials of the future.

— Christopher Alexander et al., A Pattern Language, p. 958

Other patterns focus on life experiences such as the Street Cafe (Pattern 88):

The street cafe provides a unique setting, special to cities: a place people can sit lazily, legitimately, be on view, and watch the world go by […]. Encourage local cafes to spring up in each neighborhood. Make them intimate places, with several rooms, open to a busy path, so people can sit with a coffee or a drink, and watch the world go by. Build the front of the cafe so a set of tables stretch out of the cafe, right into the street.

— Christopher Alexander et al., A Pattern Language, p. 437,439

Grouping these patterns, the authors say, they form a kind of language, each pattern forming a word or thought of a true language rather than a prescriptive way to design or solve a problem. As the authors write on p xiii, "Each solution is stated in such a way, it gives the essential field of relationships needed to solve the problem, but in a very general and abstract way—so you can solve the problem, in your way, by adapting it to your preferences, and the local conditions at the place you are making it."

A notable value is the architectural system consists only of timeless patterns tested in the real world, then reviewed by multiple architects for beauty and practicality. The patterns include provision for future modification and repair, in keeping with the principle the most-satisfying living spaces are those which, like the lives of their occupants, tend to change and evolve over time.

The book values human rights such as freedom, and it shows how architecture can enhance or reduce an individual's sense of freedom

[…] we are saying a centralized entrance, funneling everyone in a building through it, has, in its nature, the trappings of control; while the pattern of many open stairs, leading off the public streets, direct to private doors, has, in its nature, the fact of independence, free comings and goings.

— Christopher Alexander et al., A Pattern Language, p. 742

This book's method was adopted by the University of Oregon, as described in The Oregon Experiment, and remains the official planning instrument.[2] It is adopted, in part, by some government agents as a building code.

Alexander's conception of patterns, and pattern languages, were major factors in the creation of Ward Cunningham's WikiWikiWeb, the first wiki, intended as an archive and discussion web application for the Portland Pattern Repository.[3]

The idea of a pattern language applies to many complex engineering tasks. It is especially influential in software engineering, where design patterns are used to document collective knowledge in the field.[4][5] In that field, it was a major inspiration to Richard P. Gabriel before he wrote Patterns of Software.[6]

Will Wright cited the book as one of his inspirations for creating SimCity 2000.[7]

The eight books in the Center for Environmental Structure Series are:[8]

• The Timeless Way of Building (volume 1)
• A Pattern Language: Towns, Buildings, Construction[9] (volume 2)
• The Oregon Experiment (volume 3)
• The Production of Houses (volume 4)
• The Linz Café (volume 5)
• A New Theory of Urban Design (volume 6)
• A Foreshadowing of 21st Century Art (volume 7)
• The Mary Rose Museum (volume 8)

• Christopher Alexander, Sara Ishikawa, Murray Silverstein (1974). 'A Collection of Patterns which Generate Multi-Service Centres' in Declan and Margrit Kennedy (eds.): The Inner City. Architects Year Book 14, Elek, London. ISBN 0 236 15431 1.
• Alexander, C. (1979). The Timeless Way of Building. USA: Oxford University Press. ISBN 978-0-19-502402-9.
• Grabow, Stephen: Christopher Alexander: The Search for a New Paradigm in Architecture, Routledge & Kegan Paul, London and Boston, 1983.
• Schuler, D. (2008). Liberating Voices: A Pattern Language for Communication Revolution. USA: MIT Press. ISBN 978-0-262-69366-0.
• Leitner, Helmut (2015): Pattern Theory: Introduction and Perspectives on the Tracks of Christopher Alexander. ISBN 1505637430.

• Pattern Language - Official web site of Christopher Alexander.