I am a young architect in Hanoi. As someone who designs urban houses, I can tell you that the narrow house design mainly stems from historical land division and efficient space usage. In old Hanoi, land was divided into long, narrow lots so that every family could have street access. Taxes were calculated based on the width facing the street, not the depth, which encouraged people to build slim but deep homes. Northern Vietnam has four distinct seasons, so tube houses often have skylights or inner courtyards to promote ventilation during the humid summers and help retain warmth during cold winters. When I design today, I often add double-layered doors, backyard gardens, and balconies full of plants to make these narrow houses breathe better amid the dense city.
HCMC, same things
