More than 10 million Colombians live in housing at risk of collapse in an earthquake, a landslide or a flood, most of them in urban slums. Home improvement in such communities is constrained by factors including lack of capital, poor-quality building materials, inadequate construction practices and difficult-to-apply building codes.
Yet Colombia as a whole has been enjoying sustained economic growth and greater political stability over the past 15 years and is shaping up to be one of Latin America’s fast-growing economies in 2015. Rising prosperity has enabled significant consolidation of poor, densely populated neighbourhoods, and municipal governments in larger cities have significantly improved infrastructure.
While these developments have been positive in most respects, they have also contributed to uncontrolled densification of housing and increased seismic risk. Older, traditional homes, which faced little risk of collapse in an earthquake due to their lightweight construction, have been replaced by large multistory masonry and concrete structures without professional design or supervision using inadequate materials and dangerous configurations.
National and local governments are aware of the resulting risks and vulnerabilities. The municipalities of Bogota and Medellin, for example, have allocated funds for retrofitting, or strengthening, homes in neighbourhoods prioritised for this type of intervention. In Bogota, more than 1,400 families have requested retrofitting subsidies from Caja de la Vivienda Popular, the municipal subsidy provider.
Despite considerable interest among city governments and homeowners, far fewer retrofits have been completed than safety would demand because the current approach to evaluation and design has proved expensive and difficult to implement, and the required paperwork and legal hurdles discourage homeowners and even public officials from proceeding. Meanwhile, the stock of disaster-vulnerable housing keeps growing – along with the risk of disaster.
The goal of this collaboration with the Swiss Re Foundation is to develop Caja de la Vivienda Popular’s capacity to implement seismic evaluation and retrofits in Bogota by tapping existing public subsidies.
To accelerate the retrofitting of unsafe structures, in 2014 the social enterprise Build Change developed an easy-to-use, code-compliant retrofit evaluation and implementation procedure in partnership with Colombia’s National Learning Service, Swisscontact and the seismic engineering community in Bogota.
In particular, Build Change developed two training curricula – targeted at engineers and construction workers, respectively – to serve as a starting point for evaluating one- to three-story masonry houses for seismic risk, designing structural upgrades if needed and implementing the retrofits. The National Seismic Construction Commission approved the use of Build Change’s methodology in Colombia in May 2015, and initial training of Caja de Vivienda Popular’s staff, supervisors and contractors began the following month.
Supported by the Swiss Re Foundation, the first stage of the project will introduce the methodology and serve as a pilot, starting with 50 home retrofits in Bogota that will be completed with close supervision and mentoring from Build Change. The second stage will involve a more extensive implementation in Bogota and another large city in Colombia. By the end of the project in 2017, both cities should be capable, depending on the availability of public funds, of executing at least 5,000 retrofits per year and scaling up further.
Approximately 250 people living in the 50 homes to be retrofitted in the first stage of the project will benefit directly from this collaboration. Moreover, many thousands of other residents of disaster-vulnerable housing stand to benefit from the lessons learned and capacities built in the two cities targeted in the project as a whole, as do millions of other Colombians whose homes are currently at risk.