# 5.2 The Emissions Savings From Strengthening and Expanding Homes in Post-Earthquake Haiti
| Location | Port-au-Prince (2010–2018) and Les Cayes and surrounding areas (2021–2022), Haiti |
|---|---|
| Context | Post-disaster (2010 and 2021 earthquakes) |
| Number of Houses Analyzed | 78 retrofit, 53 new construction |
| Hazards | Earthquake, wind |
| Building Type | Concrete block masonry with lightweight or reinforced concrete slab roof |
| Intervention Scope | Repair and retrofit, some with vertical expansion to add a second story |
| Performance Level | Life safety |
Program Details
Build Change’s Haiti program has included numerous housing retrofit projects over the past decade. All projects have been in a post-disaster context following the 2010 and 2021 earthquakes, which means that the interventions include both repair and reconstruction of damaged elements as well as strengthening of the existing structural system. For example, in addition to rebuilding collapsed walls and repairs to the roof, the scope of work may also include new tie columns at wall intersections and new reinforcement around window openings.
The houses are a mix of one- and two-story masonry buildings with timber hip or concrete slab roofs. All suffered damage during an earthquake and require repairs as well as structural strengthening. Repair interventions include: reconstruction of masonry walls, reconstruction of lightweight (timber-framed, metal sheet clad) roofs, construction of hollow core concrete block slab, and repairs to damaged concrete slab roofs. The most common structural strengthening measures are new reinforced concrete confining columns at walls ends and intersections, and either side of door and window openings.
Before
After
Before and after Build Change technical and financial support for repair and retrofit of Aurore Medard’s home
Before
After
Before and after Build Change technical and financial support for repair and retrofit of Naomie Gobert’s home
Findings
Overall, home improvements in Haiti save 59 percent of the emissions of equivalent new construction. On average, post-disaster repair and improvement of existing homes in Haiti saves 20 metric tons of carbon dioxide per house (0.26 tons per square meter).
Emissions savings are slightly lower for Haiti compared to the global average for programs without expansion, largely due to the considerable extent of post-earthquake repairs that were required. For interventions without expansion, the savings in Haiti were 65% of equivalent new construction - slightly lower than the global average savings of 68%. Similarly for interventions with expansion, the savings were 42% and 47% for Haiti and the global average respectively. This is predominantly due to the severity of the earthquake damage and the extent of repairs that were required to the houses. A secondary factor is that Haiti relies heavily on imports for cement, steel reinforcement, timber, and roof sheets, which increases the emissions from transportation.
The biggest emissions savings in Haiti were for houses with repair and strengthening interventions, but house interventions that included vertical expansion also had significant emissions savings. The Haiti program provides an interesting post-disaster context comparison of the impact of vertical expansion on total embodied carbon. All houses had extensive damage repair and structural strengthening interventions, and only some houses also had vertical expansion. While the houses without vertical expansion saved, on average, 71 percent of the emissions of equivalent new construction, the houses with vertical expansion still had average savings of 42 percent of equivalent new construction.
