These streets still keep the same appearance that they had at the end of 19th century.
Prior to the French colonial period these streets all had the same appearance and were laid out in an order similar to a chessboard. Most of them were named after the goods manufactured or sold there. For instance, Hang Duong means “Sugar Street”, Hang Bac – “Silver Street”, Hang Bo - “Bamboo Basket Street”.
The houses in these streets are called tunnel houses. The house has the shape of tunnels, being very long and narrow, it sometimes opens at the back into another street, which is different from that of the front entrance door.
All the houses are similarly arranged with their front rooms serving as places where goods are manufactured or sold, with small open courtyards to let light in, usually decorated with ornamental rocks, little water-pools with gold fish, ornamental plants and flowers. The backrooms serve as the living quarters with a dining room and bedroom.
Most of these houses are covered with small tiles which have the characteristic feature of: two walls of the gable being built so that they are higher than the roof, resembling a staircase with two funny pinnacles.
Tunnel houses are simple and narrow serving both as a place of manufacturing or selling products and as a dwelling house for the family. In these streets, the shops are open all day long, and even in the evening, the quarter is always interesting to walk around. This community of people shares the same fate and they are all united by feelings of solidarity.
The old houses reflect the cultural development of Hanoi. Most of the houses have a brick structure with wooden beams or a structure of force-resistant wooden beams with raising pieces supporting the tiles.
To make the beams, precious timbers, such as Dinh (Markhamia stipulate), teakwood and ironwood are used.
However, what astonishes researchers as well as today’s generation is that all calculations for making the house structures were made by workers who had never joined a training course, but only depended on their traditional experience.
In the late 19th and early 20th centuries, most houses had a roof made of double tiles or toe cap-shaped tiles.
The edges of the roof were decorated with patterns of an old architectural style, creating natural waves.
All decorative patterns and the roof’s edges were delicately carved by the artisans.
In the 1920s, mingling with houses of typical architectural style in Hanoi were houses with roofs of the Indochinese architectural style.
The outstanding feature of this style is a system of sloping tiled roofs and overlapping tiled roofs, which has similar advantages as the Vietnamese traditional roofs.
One of the projects typical of the interference between the French style and traditional style is the head office of the Ministry of Foreign Affairs on Dien Bien Phu Street in Hanoi.
The project, designed by a French architect, has a system of roofs, including the octagonal roofs over the towers rising above the large roof of the main building structure, a small roof over the windows of the second floor and roofs over the gables.
The overlapping roofs help ventilate the building and shield it from sunshine and the heat.
The skilful combination of the two architectural styles makes the structure highly applicable while retaining the Vietnamese traditional features.
In addition, the architecture of houses in Hanoi was more or less affected by the styles of the Chinese immigrants, making the streets in Hanoi livelier.
In the past, the workers only used common decorative patterns, such as “Two dragons flanking the moon” or “Dragons playing with clouds”.
Later, additional decorative pattern of creeper flowers were made under the double tiled roof, making the house look mysterious and luxurious.
The ancient streets have undergone some alterations owing to historical upheavals, social adaptation and the appearance of some new construction, but they still remain virtually unchanged.
So this is why this area with small tunnel houses, crowded streets, pagodas and temples, with curved roofs and green trees, all gives Hanoi it’s own particular original beauty.
The interference of cultures has left unique architectural styles in Hanoi that few cities in Vietnam have.