Costa Rica is located 10 degrees north of the equator and has a tropical humid climate. Especially the southern pacific where we are located is an area with tropical rain forests in contrast to the Gunacaste area which has tropical dry forests. The climate is characterized by a short dry season from January to April and a green or rainy season the rest of the year. Humidity levels are high year long and the amount of rainfall can be an amazing 13 feet a month. Despite the rainfall the sun is strong during the entire year. Air temperature on the other side is cool at night at 18C (65F) and still comfortable at 26C (80F) during the day.
With such an extreme climate architecture and design has to be different than in most places in the USA exempt perhaps parts of the southern states like Florida. Lots of Expats make the mistake to bring their home designs from the states which where designed for cooler and dryer climates. Others bunch all Latina America together and confuse dry Mexico with the tropics.
What are the main design Elements for a Tropical Home in the Southern Zone of Costa Rica:
Sufficient Airflow is one of the most important aspect for the home design. Stale and non moving air will bring rot, fungus and mold into your house. It does not matter what your house is built of if the air is not moving mold will come within a couple weeks. Mold grows on the glass inside high end optical camera lenses in one rainy season! Off cause you can close the house up and make it airtight but you will need dehumidifiers and air conditioners to make an artificial climate in your house. At current energy prices of 40 cents a kWH – which is 3-4 times! the price of Europa and the USA thats not the most efficient option. Besides who wants to live in an artificial climate if the temperature outside is a cool 80 F?
Large Roof Overhangs and covered outside areas protect us from the strong sun during the day and from the heavy rains in the afternoons and during the nights. All tropical designs from Bali to a Southern Home in Luisiana feature large verandas and covered porches. The sun should never touch the doors or windows during day except perhaps at sunset for a short time only. The reason is that the glass used in most windows and doors will heat up the house when the sun contacts it. This passive heating effect is used in colder climates but in the tropics we want to cool the house and not heat it up.
Walls are complementary and essentially not necessary: Even most indigenous houses in the tropics are still just a couple posts with a roof on top. In cool climates we need protection from the cold winds and air so we want to built thick walls with good insulation for heating the house. In the tropics we want the opposite so the only reason we need walls is to have privacy. There are lots of ways to deal with the privacy issue from planting around outdoor showers and sides of a porch which need protection to louvered walls windows and doors, wood curtains or lattice walls.
High ceilings and steep pitched roof design. The higher the room the more air will be available inside the house which is bad if you have to heat it in the winter but perfect for the tropics where hot air can rise up and vent through the roof. High pitched roofs also drain the amounts of water coming down during the rainy season better.
Water features like pools, ponds and reflecting ponds not only help to cool the body but also cool the house when warm air gets cooled over them.
What to avoid:
Massive concrete blocks and decks which store the heat during the day and heat up the house during the night. A concrete slab around your pool will be heated up during the day considerable. This heat than warms up the breezes going trough your house. Depending on the material used to cover the slab its even hard to walk on it during the day. A wood deck on the other side stays relatively cool during the day and wood also stores only minimal energy.
Big massive glass walls for the great view without any overhangs. Interestingly this style is seen a lot in Miami which has a similar climate. Without massive amounts of artificial cooling and wasting huge amounts of energy and money those houses are completely uninhabitable.
Flat roofs again a feature of Miami style buildings are a big no for tropical architecture since they will 100% leak over time. Also off cause no overhangs.
Adobe WallsWe used as an infill between our frames but I don’t think thick load bearing adobe walls have a place in the tropical humid forest. Those walls are used especially in dry areas like New Mexico or Peru but personally I have not seen them a lot in the tropics. Also they are not the most earthquake resistant designs and are therefor even against the local earthquake code.