This paper examines the grey and peer-reviewed literature that is currently available to help drive proactive private side investment in flood resilient home retrofits, identifies where gaps exist, and points to additional research that is needed to bolster retrofit adoption. 

Canadian governments, businesses, and residents currently spend a combined average of $2.9 billion every year repairing damage to homes caused by fluvial, pluvial, and coastal flooding. The distribution of losses is particularly concentrated in homes exposed to the highest levels of flood hazard. Without implementing adequate voluntary and regulatory flood risk reduction measures experts project that annual costs associated with repairing home flood damages may triple by 2030 (Ziolecki et al., 2020). 

Benefit Cost Ratio (BCR) estimates for dry flood proofing (protect) range from 11:1 for flood resilient new home construction (Porter & Scawthorn, 2020) to 6:1 for flood resilient retrofits (Porter et al., 2019). Wet flood proofing (accommodate) BCR estimates range from 6:1 for 1’ (30cm) elevation above the 100-year flood plain to 5:1 for 5’ (150cm) elevation above the 100-year flood plain (American Flood Coalition, 2022). BCR estimates for retreat range from 6:1 over 20 years (Porter et al., 2019) to 6:1 over 30 years (Nelson & Camp, 2020).

To unlock private side investment in proactive flood resilient retrofits and new builds the research identifies opportunities for all participants in the real estate value chain (builders, developers, retailers, insurers, lenders, and local governments) to work together to raise public awareness of flood risks and incentivize improved flood resilience (Porter & Yuan, 2020; Porter et al., 2023; Giannitsos, 2023; Krueger, 2022; Minano & Peddle, 2018). Support for flood resilient home retrofits in high-risk zones should be prioritized, particularly for homes that provide the country’s most affordable housing units, including basement apartments, social housing, rental homes, and apartment buildings.