I spent a little time this weekend working on my absolutely rudimentary illustration skills. I took as my object the three baptisteries that I included in a recent draft of an encyclopedia article. I worked on tracing them from well-known illustrations with an eye toward simplifying the plans to facilitate their reproduction at a smaller scale.
Producing new illustrations is almost always a good exercise in that is forces me to reflect critically on the various features included in the various floor plans. I used Illustrator for these illustrations and mostly traced them from existing plans. I did free sketch some of the features, though, and they are more illustrative than accurate.
I suspect, for example, that leaving out the thresholds and some of the features associated with the flooring at the Dura Baptistery has had little effect on how most scholars are likely to interpret the basic features of the plan: the baptistery is a room in the northwestern corner of the atrium style house.
Dura Europas Baptistery (after Wells (1967), plan 5)
Likewise, my plan of the Lechaion baptistery illustrates the complexity of the structure and the strange relationships between the two, apparently contemporary, centrally planned rooms and the long apsidal hallway to their west. It boggles the mind that an "architect" (or builder) could so carefully articulate the interior spaces of the various structures, but arrange their relationships to one another in such an awkward way. The narrow passageways linking the northern building to the baptistery proper appear to have been original to the plan, but utterly inelegant.
Lechaion (after Volonakes (1976), plan 1b)
My sketch of the Orthodox Baptistery in Ravenna eliminated some of the later features which commonly appear in plans and sought to capture the relationship between its architectural massing and the central baptismal font.
Orthodox Baptistery in Ravenna (after Kostof (1965), fig. 1)
I will never be confused for an architect, but the exercise of re-illustrating the plans of well-known buildings can frequently reveal some feature of aspect of the building (or even the plan) that I might have otherwise overlooked.