Is the building, San Vitale.. considered to be Byzantine .. it does not have a dome.
Yes, it's Byzantine.
http://en.wikipedia.org/wiki/Basilica_of_San_Vitale
does the exterior have byzantine features?
Read the Wikipedia article.
To determine whether the building San Vitale is considered Byzantine, we need to look at its architectural features and historical context.
San Vitale is indeed considered one of the most important examples of Byzantine architecture, despite not having a dome. Byzantine architecture encompasses a variety of styles, not limited to buildings with domes. It is characterized by a combination of imperial Roman, early Christian, and Eastern influences that developed in the Byzantine Empire.
San Vitale, located in Ravenna, Italy, was constructed in the 6th century under the rule of the Eastern Roman Emperor Justinian I. It showcases many distinctive features of Byzantine architecture. The building is known for its centralized octagonal plan, two-tiered colonnaded arcades, and rich mosaics adorning the interior walls.
Although domes are often associated with Byzantine architecture, they are not a defining characteristic. Byzantine builders were skilled in various architectural techniques beyond domes, such as vaulting and pendentives. San Vitale utilizes a wooden roof rather than a dome, which was a common choice for large-scale public buildings during this period.
Therefore, while San Vitale lacks a dome, its architectural style, intricate mosaics, and historical context firmly place it within the category of Byzantine architecture.