In conceptual architecture, the finished building as product is less important than the ideas guiding them, ideas represented primarily by texts, diagrams, or art installations.
Architects that work in this vein are Diller + Scofidio, Bernard Tschumi, Peter Eisenman, and Rem Koolhaas.
Conceptual architecture was examined in the essay "Notes on Conceptual Architecture: Towards a Definition" by Peter Eisenman in 1970, and again by the Harvard Design Magazine in autumn 2003 and winter 2004, by a series of articles under the heading "Architecture as Conceptual Art?
But the understanding of design as a construction of a concept was understood by many modernist architects as well.
To quote Louis Kahn on Frank Lloyd Wright: