This study analyzes the composition by a high school senior of a house design for a class in architectural design. He produced this text in relation to the readings of that text by his teacher and other potential readers. The authors take a Vygotskian perspective to understand the settings, goals, and tools through which he composed his architectural plans, drawing on a cultural theory of reading to analyze how this text was understood by his most immediate reader, his teacher. The data include field notes based on daily observations of the semester-length course, an observation-based interview with the teacher, artifacts such as the student's drafts and final design, a recorded feedback session in which the teacher discussed the drawing with the student, a concurrent think-aloud protocol provided by the student while designing his house, and a retrospective protocol in which the student reflected on his composing process using the completed architectural design as a stimulus. The analysis identified a set of processes and social relationships involved in the composition and reading of the house design, including the role of cultural knowledge and practice in the student's apprenticeship into an approach to architectural design, tensions between goals of the student and his evaluative readership, tensions between definitions of economics that informed different conceptions of house design, and tensions between the student's inscription of meaning in the architectural text and his teacher's encoding of meaning in his reading of this text. The student's negotiation of these processes and tensions contributed to what was understood to be the larger project in which he was engaged, that being his ongoing development of an identity and life trajectory.