The teacher-centered side of this metaphor came quite quickly to me, the student-centered aspect was a bit more difficult. The clarity came to me by re-reading my notes on the Brown article which describes two types of knowledge; explicit and tacit. As an architect, the professional transmits to the construction team `what to do`and in large part, the construction team takes action and enters the realm of tacit knowledge. The system that is required in the establishment and construction of a complex structure requires various experts to work together similar to a learning knowledge-building community (Scardamalia and Bereiter). So this is for the most part, the student-centered aspect of the architectural metaphor; an architect needs other experts (construction worker and such) who are going to take the plan and knowledge of the architect and put it into action. Much like how a teacher plans and transfers knowledge to students who must take the knowledge and use it to practice skills, attribute meaning, and build upon.
Brown, J.S. (2002). GROWING UP DIGITAL: How the Web Changes Work, Education, and the Ways People Learn. Journal of United States Distance Learning Association, 16(20). http://www.ux1.eiu.edu/~cftde/3001F03/seely.html
Scardamalia, M., & Bereiter, C. (1994). Computer support for knowledge-building communities. The Journal of the Learning Sciences, 3(3), 265-283. http://hrast.pef.uni-lj.si/~joze/podiplomci/prs/clanki03/CSILE_Scardamaila.htm