Note that the walls are made of masonry reinforced with rebar. That provides strength in case there is an earthquake. Even interior walls are masonry. The walls are covered with a very smooth plaster-like cement on the inside.
You can see several construction workers in the warm December sun. Many construction workers in Costa Rica are immigrants or migrant construction labor from Nicaragua.
This photo also shows differences in construction practices between the developing world and the USA. My wife and I have knowledge of the standards of the U.S. Occupational Safety and Health Administration. In the USA, an OSHA inspector would issue citations for the lack of guard rails on the scaffolding and the lack of caps on the rebar, among other things. Nevertheless, construction methods on Costa Rica are better than you would see in other Latin American countries. This construction site had a large crane to deliver materials. The quality of construction evident in this photo is good.
This week on our travel photo site, Viva la Voyage, we happen to be showing photos from Costa Rica, which of course is what I show in this site every day. Some of our favorite Costa Rica photos are featured this week.