The most common type of ancient house in Hoi An is the tube house, characterized by an absence of side windows. One end faces the river, while the other opens to the street. A central courtyard allows natural light to enter and helps regulate airflow. Most of these houses were constructed with wooden frames, surrounded by brick walls or wooden panels. This traditional design keeps the house cool in summer and warm in winter. The roof structures vary, featuring designs such as trusses and beams. They are covered with yin-yang tiles, giving the houses a robust yet elegant appearance.

In addition to their distinctive architectural style, the ancient houses of Hoi An are adorned with exquisite carvings that enhance their interior decor. For example, the Tan Ky House is renowned for a pair of inlaid mother-of-pearl calligraphic couplets, which have withstood the test of time: “Bách xích thủy dương thiên lý vũ – Thập phần minh nguyệt nhất lâu thư” (A hundred boats race along the river in the pouring rain – The bright moon shines upon the books in a tower). These poetic lines describe the beauty of moonlight illuminating every corner of the house. Similarly, the Duc An House features a collection of horizontal boards and couplets with notable phrases like “Duc An hieu” and “Am ha tu nguyen” (When drinking water, remember its source).