A City Is Not a Tree

A City Is Not a Tree is a widely cited ^[1] 1965 essay (later published as a book) by the architect and design theorist Christopher Alexander, first published in the journal Architectural Forum, and re-published many times since.^[2] In 2015 the essay was published as a book including new exegesis commentaries on the original essay from other architects, engineers and physicists.^[3] A City is Not a Tree has been widely described as a landmark text, and the Resource for Urban Design Information calls it "one of the classic references in the literature of the built environment and related fields".^[4] In 2016 a 50th Anniversary edition was published by Sustasis Press/Off the Common Books.^[5]

A City Is Not a Tree

Author	Christopher Alexander
Series	Center for Environmental Structure
Subject	Architecture
Publisher	Sustasis Foundation
Publication date	2015
Pages	241
ISBN	978-0-98-934697-9
Preceded by	The Battle for the Life and Beauty of the Earth

Its core contention is that urban planners tend to design cities as tree diagrams (with each node only having a relationship with a parent node), while successful unplanned cities have a semi-lattice structure (where each node has relationships with many nodes).