The Alt House Floor Plan
In the early 1860s, William J. Alt (1840–1908) hired master carpenter Koyama Hidenoshin (1828–1898) from Amakusa, Kumamoto to build a house at No. 14 Minamiyamate, one of the most desirable residential lots in the Nagasaki Foreign Settlement. Koyama was known as a capable builder who could adapt Japanese construction techniques to meet the preferences of Western clients. Construction of the house began in 1865.
The floor plan of the Former Alt House was preserved by the Koyama family. The paper bears the watermark “C. Ansell, 1863,” the name of the paper manufacturer and the date the paper was made. The names of the rooms and their dimensions are written in English, but the builders added notes and measurements in Japanese to facilitate the construction process. The document provides a valuable glimpse into the early meeting of Western and Japanese architecture.