National Register of Historic Places in Napa County
The Alexandria Hotel was designed by Napa architect William H. Corlett and built in 1910. The annex is older than the hotel and was redesigned to match the hotel when the hotel was built.
According to the NRHP nomination, Corlett's design for the building combined elements of the Mission Revival style and Mediterranean Revival style, both of which were popular in California in the early 20th century. However, to this observer, the architectural style is primarily Italianate, especially the fenestration which incorporates Palladian windows.
Source: Adapted from the NRHP nomination submitted in 1982.