Change is something that many people fear and avoid; however, progress in construction methods is a must for Haiti. After designing and building my own project, a 9,000-square-foot home, over the past two years, I have dealt with the Haiti building industry and have done extensive research that boils down to a few rules of thumb for Haiti’s seismic and hurricane conditions. Of course, specific sites and specific designs will require their own detailed considerations.    

Seven months after the earthquake in Port-au-Prince. Photograph by Pascale Saint-Louis

This summer during my vacation I traveled to Haiti to share my knowledge. I began distributing my findings to as many organizations as possible and met with twenty construction workers and engineers. They were surprised that such simple measures could make better buildings. Through these recommendations, which include site selection, building form, roof, construction materials, and methods, Haiti can have a smart reconstruction and new beginning. The price for not moving forward is too great.     

Site Selection     

• Avoid sites with loose sand, gravel, or sensitive expansive clays,
• Avoid building on hilltops or in deep closed-in valleys, especially above or below potentially loose rocks and boulders.
• Locate buildings away from the open sea, riverbanks, and bodies of water, which can experience tidal waves after seismic shocks.

Building Forms     

• Seismic separation: If the building masses are different sizes then completely separate the forms to make their structural systems independent.
• Avoid building reentrant corners, interior angles whose apex faces into the building massing (L, T, U and cross-shaped buildings), which are generally weak and need extra strengthening.
• Building Diaphragms: Shear walls should be continuous to the foundation to properly transfer all loads. Avoid large openings in the slab near the shear wall, as well as in the shear wall itself.
• Avoid top heavy buildings that are thinner at the bottom than the top—they could easily overturn. Similarly, buildings supported on columns in their first story should be stiffened by bracing.

Roof     

• Hip-roofs are considered a better configuration for high wind and hurricane prone areas. These four-slope roofs perform better than the gable roof’s two slopes.
• While flat roofs seem to dominate Haiti, wind researchers have found that a 30-degree roof slope is optimal.
• Use lightweight roof materials to avoid a chain reaction of progressive collapse.
• Balance internal and external pressures, and reduce uplift with an opening in the negative wind pressure zone.
• Porch roofs and overhangs are often subject to high wind uplift forces—structurally disconnect them from the main structure. Similarly, roof cantilevers should be no more than 50cm; provide larger cantilevers with an opening to reduce wind pressure.
• Avoid cladding with roof tiles—during hurricanes they are brittle, break easily, and become windborne missiles.

Construction Materials and Methods     

• Use good quality building materials, i.e. do not use beach sand for mortar.
• Maintain the same construction type for the structure’s full height.
• Extend the foundation to bedrock, especially in loose sub-soils.
• Avoid unreinforced masonry, and use a high quality mortar—extremely important!
• Tie the tops of masonry walls together with a bond beam.
• Wherever walls and foundations meet, tie them together with steel reinforcing
• Walls need to resist lateral forces and be as continuous as possible. Keep window and door openings 60cm from the corners.
• Concrete block walls should contain reinforcement that runs vertically through the block’s voids and laterally between courses.
• During a hurricane, winds can unhinge exterior doors—make sure they swing out!
• Pour columns in one single pour. Structural failure often occurs in concrete columns because they were poured in stages.
• DO NOT leave rebar exposed on any part of the building. Air and water will penetrate the concrete through the rebar and corrode the structure of the building from the inside.

Reinforcing bar left exposed. Notice the vertical rebar left exposed in anticipation of adding another level. Photograph by Pascale Saint-Louis

I highlight these items as quick rules of thumb that come from the many articles and reference materials I have researched. I continue to distribute these key documents  to Haitian contractors and architects, such as those produced by Architecture for Humanity: Architecture for Humanity: Rebuilding 101 and Architecture for Humanity: General Recommendations for Improved Building Practices in Earthquake and Hurricane Prone Areas. The document Groupe Odyssey S.A.: Damage and Need Assessment Report also contains noteworthy information. Furthermore, I continually respond during my personal time to inquiries from contractors and engineers in Haiti wanting to get further information. I hope to return soon to continue this personal mission and hopefully see advancements in the industry, advancements sorely needed.  

Much of my research is inspired by Tara Francesca Beauge, my cousin, who died on January 12, 2010 as victim of the Haiti earthquake. Photograph by Pascale Saint-Louis