PORT-AU-PRINCE, Haiti (AP) -- On a steep hillside on the edge of Haiti's capital, Pacha Jeudy slaps soupy cement onto jagged cinderblocks and stacks them into a wobbly wall. The home looks likely to collapse in a big earthquake, just as his neighbors' houses did in the January 2010 temblor.
Less than a mile down the hill, construction workers are adding two floors to a three-story office building. The owners couldn't be located to explain their plans for the structure, but steel reinforcing bars extending toward the sky suggest that yet another floor beyond those five is in the works.
"That building kind of gives you the willies," said Dany Tremblay, a licensed structural engineer from Utah who has designed and inspected hundreds of buildings in Haiti since the quake. "I would be surprised that, by adding those levels, the building is still structurally sound."
Four years later after the 7.0-magnitude quake that toppled around 190,000 buildings and killed about 300,000 people, construction practices in the Caribbean country have improved overall, with better materials being used for many larger projects. A building code now exists and many big, well-funded projects including more than a dozen hotels, supermarkets and schools are being built to international seismic standards.
But construction of smaller commercial buildings and homes is more haphazard, in large part because most people in the impoverished nation don't have the money to do things by the book. Neighborhoods in the capital of 3 million are filled with precariously rebuilt one- and two-story homes no more secure than the ones they replaced.
Experts like Tremblay, who runs a private engineering firm here, fear that if crews don't start building homes and other structures to much higher standards, another huge earthquake could kill many people and cause widespread damage.
Located on the Enriquillo fault system with the neighboring Dominican Republic, Haiti is always at risk of another powerful quake.
As much as 90 percent of Haiti's construction is done without an architect or engineer, and much of it on unstable soil, according to a study last year by the Canadian Journal of Civil Engineering. "Seismic hazards maps are now available for the design of new buildings," it said. "Unfortunately, few engineers in Haiti are very familiar with seismic design principles and dynamics of structures."
Jeudy, a construction worker who is helping enlarge the home of his neighbor, a widow with two school-aged children, said he was taught by a foreign engineering group how to mix concrete and water to ensure blocks are strong enough to withstand major shakes. But he said tight budgets mean that the ratio of water to cement in many construction projects can fall short. "There isn't enough money," Jeudy said.
In a dusty courtyard down the street, construction site manager Paul Gaston shouted above the roar of a machine making cinderblocks far sturdier than the ones that crumbled in 2010. He said more of Haiti's smaller builders now use better materials, but safety is still often considered a luxury.
"Some people just don't have the means and they will use the same construction methods, or go back to build the way they used to," Gaston said as workers arranged the freshly made cinderblocks in rows.
President Michel Martelly's administration adopted a new building code after the Jan. 12, 2010 quake, much like other countries and cities have done following similar disasters. "Now there are codes," Prime Minister Laurent Lamothe told The Associated Press in an interview Friday. "We have different areas of supervision to make sure that the buildings are safe."
But in impoverished Haiti, the government's ability to make sure the code is being followed is extremely limited. The Ministry of Public Works has only 60 engineers to inspect construction sites in a country of 10 million.
Chevrin Joseph, one of the government engineers, said it's up to municipalities to carry out inspections and enforce codes.
There are examples of how to do build according to code.
One is a private elementary school in Port-au-Prince being built to sway if the earth shakes. Walls and corners are being strengthened with reinforced concrete, and cinderblocks use the proper ratio of cement and water.
"Every part of this building has been thought through," Canadian structural engineer Shane Copp said as he pointed to the 11-classroom school. The project is financed by Islamic Relief, an international emergency aid organization that has built three other schools in Haiti and renovated two others.
Tremblay designed the school to meet international building codes, and Copp is a consultant managing the construction.
Other international organizations and some Haitian business owners are also opting to spend more for safety when building hotels, supermarkets and other big projects.
Metal reinforcement bars known as rebar were not always used in construction here, but they are now piled up at hundreds of construction sites around Port-au-Prince, and on trucks crossing into Haiti from the Dominican Republic.
Richard Buteau, general manager of the 87-room Karibe Hotel, hired California-based Miyamoto International, a global earthquake and structural engineering firm, to retrofit the quake-damaged structure and ensure the safety of adding 100 more rooms.
"Repairing was not an option," said Buteau, whose family owns several hotels. "Anything that has to be built now has to take into consideration Haiti's new reality of earthquakes."
Buteau hired professional supervisors to oversee the Karibe's rebuilding and an expansion, as well as the addition of 85 rooms to the Kinam Hotel nearby. He also hired a private contractor to ensure the ground was suitable for building; soil erosion is common in deforested Haiti, another reason so many buildings crumbled four years ago.
The Caribbean Supermarket is among projects being built back stronger. After pancaking in the quake, it is now more strongly reinforced and is only one floor instead of two.
CEO and president Kit Miyamoto said the structural engineering firm that carries his name also inspected a dozen other properties, including a five-floor office building for the U.N. children's agency UNICEF and the Royal Oasis Hotel, and certified them as safe.
"This is something that we had forgotten for a long time -- that Haiti was subject to earthquakes," Buteau said. "Now we know. Now we know that we need to build better."
Trenton Daniel can be followed on Twitter at @trentondaniel.