This case study documents the rapid urbanization and economic development of Da Nang, a city in central Vietnam. It’s geography – being located on the tropical storm belt, and characterised by both mountain ranges and low-lying coastal areas – renders it a disaster prone city affected by various water-related hazards which translate into catastrophe on an annual basis. Typhoons are a particular threat, with storms hitting the city between 3-5 times per year and affecting 80-90% of the population. The housing sector is deemed acutely vulnerable to weather extremes and storms often cause critical damages to thousands of houses. The authors note that per capita economic development has in fact increased housing vulnerability, because residents are using newer construction materials, often without sufficient technical knowledge or safety measures. Around 70% of newer houses did not incorporate typhoon resistant features, and many located in low-lying areas did not use flood-protection features either. Furthermore, while the government has introduced disaster risk reduction (DRR) measures through building codes, they only apply to houses over 250 metres squared, and smaller houses do not face regulations. These factors renders those living in the hazard prone areas at particular risk of disaster, especially the poorest groups.

The authors use an economic perspective, through the following methods, to outline the costs and benefits of using typhoon resilient housing in Da Nang.

i) They collected city-level data related to climate hazards and damage, and built an event frequency model for creating climate scenarios and projections.

ii) Household surveys were conducted to assess past damage experienced as a result of typhoon events.

iii) Through shared learning dialogues with local stakeholders they identified climate hazards, conducted a vulnerability assessment and assessed preferences for typhoon-resistant housing.

iv) A resilient housing design competition was held to seek the best housing solutions in the face of climate change.

v) A quantitative Cost Benefit Analysis (CBA) calculated the economic efficiency of typhoon resistant housing while considering past events and damages in light of future projections.

The report concludes that innovative housing solutions are affordable and local communities are willing to invest in them if funding options are available. The CBA showed that the return on investment depended upon the year the typhoon occurred, but can be high especially if during the early years of the housing lifetime. They suggest several policy responses including providing subsidised loans, micro-insurance policies, improving awareness of vulnerable communities, and adapting building codes to ensure safer and more resilient housing.