Fire alarms in informal settlements – Are they worth it?

Fires in informal settlements are a major threat to life and property, particularly in low-income urban areas. In Cape Town, South Africa, over 2200 informal settlement fires occur annually, resulting in hundreds of fatalities and millions of Rand in losses. This paper evaluates the cost-effectiveness of fire alarm systems in Cape Town's informal settlements using the J-value methodology, which integrates societal welfare and economic considerations. Analysis of local data found that Cape Town averages 2210 fires, 282 deaths, and 2970 injuries annually, across its 181,606 informal dwellings. The results show that both Lumkani's rate-of-rise heat detector and a standard smoke alarm are highly cost-effective, with J-values of 0.247 and 0.011, respectively. The societal benefit is driven primarily by reductions in fire-related fatalities, with injury and property damage reductions contributing negligible amounts of benefit. Sensitivity and threshold analyses reveal that both systems remain justified under a wide range of assumptions, though Lumkani requires a higher, but practicable, fatality reduction to be cost-effective. The findings support investment in alarm systems for high-risk communities and highlight the need for improved data collection and real-world effectiveness studies to inform future fire safety policy and intervention design in informal settlements.