The building does not look like a single thing. That is the point. Constructed during the Japanese colonial era, it combines Western-style cement walls with East Asian-style brick eaves along the roofline, and its interior mixes Western decorative conventions with East Asian-style beams overhead. The main structure is a two-story Western-style building with a prominent steeple on the roof — an unusual feature that gives the exterior its distinctive silhouette. The total area runs to 843.73 ping (about 2,788 square meters), with the building footprint covering more than 200 ping (roughly 660 square meters). An additional Japanese-style wooden house was constructed on the property in 1920. The result is an architectural record of overlapping colonial influences: Western classicism filtered through Japanese interpretation, combined with the materials and craftsmanship of early twentieth-century Taiwan.

The grounds surrounding the residence were planted during the Japanese colonial period, and most of the trees are native Taiwanese species: ring-cupped oak, subcostate crape myrtle, banyan trees, and liquidambar. Three green maples of large diameter have survived long enough to become landmarks in their own right within the garden. These trees are older than the Republic of China's governance of Taiwan. They predate Chia-kan Yen's occupation of the house, the political upheavals of the mid-twentieth century, and the city that has grown up around them. Walking through the garden, with mature banyan roots reaching into the soil and the subtropical canopy filtering the Taipei sunlight, it is possible to feel the specific quality of time that only old trees and old buildings together can provide.

Chia-kan Yen came to occupy this residence not through formal assignment but through the logic of transition: he was there when the handover happened, and the residence became his. When he was later elected vice president, the Office of the President formalized the arrangement by purchasing the residence from the Bank of Taiwan. The house's layout reflects the expectations of a senior official's life: the first floor holds a reception room, a large dining room, and a Japanese-style wing; the second floor has a study, a bedroom, and a living room. Yen served as ROC president from 1975 to 1978, having assumed the office following the death of Chiang Kai-shek. He was a trained engineer who spent his career in economic administration — a technocrat at the helm of a state in a peculiar historical position, governing from within a compound shaped by layers of foreign influence.

On July 17, 2001, Taiwan's Ministry of the Interior designated the Former Residence of Chia-kan Yen as a National Historic Site. The designation recognizes what the building embodies: not just the life of one man but the compressed history of Taiwan's twentieth century, stored in a structure whose walls were built by one colonial administration, transferred to another government, occupied by a future head of state, and eventually preserved as a record of all of it. The Bo'ai Special Zone in Zhongzheng District — where the residence sits — is itself a layer of that history, a carefully managed area of Taipei that contains some of the most historically significant buildings in the capital. The residence is quiet by the standards of central Taipei. The trees are old. The architecture says several things at once.