Modeling Rental and Multi-family Post-Disaster Housing Recovery

Emily Mongold, Rodrigo Costa, Adam Zsarnoczay, Jack W. Baker

Post-disaster housing recovery models increase our understanding of recovery dynamics, vulnerable populations, and how people are affected by the direct losses that disasters create. Past recovery models have focused on single-family owner occupied housing, while empirical evidence shows that rental units and multi-family housing are disadvantaged in post-disaster recovery. This project proposes an agent-based housing recovery model that includes the four common type-tenure combinations of single- and multi-family owner- and renter-occupied housing. The proposed model accounts for the different recovery processes, emphasizing funding sources available to each type-tenure. The outputs of the model include the timing of financing and recovery at building resolution across a community. 

The model is demonstrated with a case study of Alameda, California, recovering from a simulated M7.0 earthquake on the Hayward fault. The processes in the model replicate higher non-recovery of multi-family housing than single-family, as observed in past disasters, and a heavy reliance of single-family renter-occupied units on Small Business Administration funding, which is expected due to low earthquake insurance penetration. We find that multi-family housing relies more on Community Development Block Grants for Disaster Recovery (CDBG-DR), and has the highest total need and highest portion of unmet need remaining. However, many of these unmet cases have a large portion of their funding, and thus may practically be able to obtain the funds from personal sources.