here is a nice explanation:
The concept of the Town Architect was developed during the first Seaside Charrette held in the summer of 1983. During the charrette it was concluded that someone must supervise and interpret the implementation of the Seaside Plan and Code. It was also hoped that those who purchased properties in Seaside would hire the Town Architect to design their cottages. The first Town Architects were members of the “Night Crew”, those working at the 1983 charrette, who were responsible for the layout of streets and early buildings. Over the years Seaside has evolved and so has the role of the Town Architect. In the beginning the Town Architect would work with homeowners and builders to draft their cottages. Now, with Seaside nearly complete, the Town Architect often acts as the architect on record or works with the homeowners chosen architect on code and regulations.
http://seaside.library.nd.edu/essays/town-architects