Use a compass!
Peasant societies around the world are usually characterized by simple belongings and a high level of generosity. From what I hear, this seems to be true of Haitians in both cities and the country. Their buildings are also usually very sensitively located in response to sun and wind.
Many temperate climate cultures face doors east or southeast (in the northern hemisphere) so that the buildings will warm up more quickly in the morning. They also don't overheat as much because less afternoon sun will blast into them.
Americans and Europeans from cold countries heat and cool buildings artificially. Many of us have lost sensitivity to the realities of creating comfort outside.
Many Haitians have not lost this sensitivity, because they live outdoors. But they may be reticent about trying to tell foreign helpers how to do things. We must ask- where do you think it should be placed? Tell me why this will be best? We all need to put aside our pre-conceptions and listen.
Haiti's climate is complicated by its high mountains, to 8,000 feet altitude. At sea level (like in Port au Prince) it is a very hot and humid climate, requiring breeze and shade for comfort. Yet higher altitudes are cooler. Medium levels may need less ventilation (the suburbs around Port au Prince are higher and cooler). In the higher parts of the Haitian countryside temperatures are too cool, and shelter from the breeze may help make outdoor areas pleasant.
I looked into a scholar's study (Vlach's Sources of the Shotgun House ) of more than 30 traditional Haitian houses in and around Port au Prince. He did not comment on direction, but he drew layouts and north arrows. This is what I found:
The Haitian ti-kay or shotgun houses of this study have porches that face the road. Although you'd think 1/4 of them would have west facing porches, about 1/6 of them did. North and east were most often used for the porch.
Also, more of them were oriented east to west than not. When the long sides face south and north like this, much less low sun in the evening can cause overheating. Try to aim your buildings to follow the slope and to catch the breeze (find out where it is). But it may also be important to keep your building's long side facing south and north as much as possible.
And, of the small houses in this study, of one or two rooms, few had any doors opening to the west. Those with tiny houses cannot take refuge in different rooms or on the other porch in the shade. When building shelters and transitional houses, allow people to locate them so that their indoor and outdoor areas can be comfortable.
East facing doorways may also be best for the middle and higher elevations of Haiti. In a cool area, one may prefer south facing to north, and southeast doors and porches to northeast.