Vernacular architecture is a term used to categorize a method of construction which uses immediately available resources to address immediate needs. As such, it is often dismissed as crude and unrefined.
The term is derived from the Latin vernaculus, meaning "native," and therefore refers to all architecture which is indigenous to a specific place (not imported or copied from elsewhere). As this represents the majority of historical construction (and much continuing practice in developing countries), it is often confused with "traditional" architecture. Vernacular architecture may, through time, be adopted and refined into culturally accepted solutions, but only through repetition may it be become "traditional." Through such processes vernacular architecture can provide highly sophisticated adaptation to both the environment and to user's needs.

Once regarded as obsolete, vernacular architecture is now the subject of serious academic study, and is increasingly considered a potential component of sustainable development for its quality of adaptation to the local environment. An early work was Bernard Rudofsky's 1964 book Architecture Without Architects: a short introduction to non-pedigreed architecture, based on his MoMA exhibition. The book was a revolutionary reminder of the legitimacy and "hard-won knowledge" inherent in vernacular buildings, from Polish salt-caves to gigantic Syrian water wheels to Moroccan desert fortresses, and was considered iconoclastic at the time. The most comprehensive work is the "Encyclopedia of Vernacular Architecture of the World" published in 1997 by Paul Oliver of the Oxford Institute for Sustainable Development. Oliver has argued that vernacular architecture will be necessary in the future to "ensure sustainability in both cultural and economic terms beyond the short term." Christopher Alexander, in his book A Pattern Language, attempted to identify adaptive features of traditional architecture that apply across cultures. Howard Davis's book The Culture of Building details the culture that enabled several vernacular traditions.

Some extend the term to include any architecture outside the academic mainstream. The term "commercial vernacular," popularized in the late 1960s by the publication of Robert Venturi's "Learning from Las Vegas," refers to 20th century American suburban tract and commercial architecture. Unlike traditional vernacular, however, the design and construction of these types of buildings is remote from their eventual users, and does not represent long cultural traditions. Those who study "traditional" vernacular architecture hold that these characteristics define a more useful and fundamental partition of architecture into vernacular and non-vernacular, rather than academic acceptance of architecture.

An architect whose work exemplifies the modern take on vernacular architecture would be Samuel Mockbee, whose pioneering work with Rural Studio is well-regarded and widely discussed amongst practicing architects and academics alike.