Design in extreme climate conditions

Península de Osa, Costa Rica

By Eduardo Valverde

For towsends of years, the first nations of the southern region of Costa Rica have been building their dwells in conditions of extreme weather. During the first half of  the 20 th century , the engineers of the United Fruit Brands also had to deal with this conditions in order to provide a functional place to live for the workers. The following document gathers information collected on site, much of  it from direct observation, books and interviews.  The main idea is to show to the reader that it is possible, even in areas so extreme like the area of study, to build in an a way that it is enviromentally friendly. Architecture for the human being, but still in harmony with nature.

Our planet is in trouble!! Our population is growing and we seem not to be doing a good job distributing food and other basic needs. The global warming phenomena makes it even worse causing river floading, hurricanes, landslides, earthquakes and tsunamis. We are aware of what is causing this, but what can we do to solve or at least reduce our impact on our fragile planet??  In Osa, the first nations lived before the arrival of the Spaniards, using pretty much what they could find around them to build their houses, heal their bodies, and eat. Altough they never built big pyramids like the upper American tribes, they had very well organized comunities, developing art to a point that is still a mystery for most people today.

  A really good example of this, is the round stones of Diquis found on the area during the settlement of the United Fruit Brand operations in the 1930´s . Varying in size, from 10 centimeter to 2,57 meters, the spheres where built with three different materials found on the ridges of the Peninsula. Gabros, Granodiorita and Calcita are the basic materials used to make spheres. Other important pieces of handycraft were the objects made with gold like frogs, eagles and other zoomorphic figures. Architecture wise, as I mentioned before, this region of the Americas wasn t as developed as other cultures, nevertheless, some important promenades and important vestigious of  an incipient architecture were found on site. The constant floading of rivers, plus the intense heat and extreme humity appeard to be one of the reasons the settlements had to move from lowlands into higher territories.

 Upon the arrival of the United Fruit Brands company, the area was pretty much inhabited by the Boruca indigenous group.They already had a lot of influence from white people to the point that very few of them knew had to speak their dialect. As an interesting note, I remember having a few of these Boruca as my classmates in highschool, only one of them,named Alfrides, knew how to speak the dialect. He told me he learned it from an older woman from the comunity when he was already grown up.

The ancestors of the Boruca Indians were the ones that built the round stones. They told me how there is a plant that can make the rock soft to shape it out easier and how there is another plant to shape out gold and one to make the wood hard as a rock.

 My father used to tell me: never do anything bad to the indians, they put a spell on you and ruin your life. But where does this magic came from? The mystic world of Indians came from nature. The had learned to conduct this energy into wisdom, wisdom to know when things were gonna happen, to know when to hunt and when to grow. Their deep understanding of this concepts and  their deep respect  of nature made their lives posible in such extreme climate condition, causing little impact on nature.

But, how can we learn from nature and those first engineers how to build in such extreme conditions without causing irreversible damage? Let s see.

 The Osa peninsula has an average temperature of 30 degrees celsius( 86-90 F) 89-92% humidity, and about 2700 mm of rain at year, plus salty air called salitre in spanish ruins everything built with iron and steel even when protected with anti-rustpaint. The wood is quickly ruin by extreme humidity and proliferation of mold, fungus and lichens, plus, during the rainy season in some of the most rainy areas, the wood absorbs water and it expands causing doors and windows to get stock in their frames. Another big problem is the soil. Ultisols are the most common type on the area, which is very poor  in nutrients with  high concentrations of iron and aluminum, when the iron oxidizes make the soil red, which is a strong stain. The ultisols have poor permeability, so when it rains hard, flat terrain floads causing water to leak into houses if these are right on the ground. Another problem is that not many types of plants grow in these acidic soils, wich makes it hard to grow vegetation on it, the forest solves this problem by creating a layer of rich soil from the decomposition of leaves fallen from trees and from death animals, such layer, it’s only a few inches thick, that’s why the root system of trees it´s so superficial, and this is why the trees develop butresses as extra support. For this reason, planting a garden around your home in Osa might be challenging depending on where you are. Leting the forest grow by it self creating a layer of vegetable matter can be a good option, fast growing plants like some species of grass and others can develope a root netting that would build and hold the good soil until enough of it is created to support the bigger plants.

Most of the material used in the construction of homes by the first nations were found just around the corner, in the forest, for example palm leaves for the roof such as those from the fish tailed palm( Asterogyne martiana), Chonta Palm( Socratea exhorriza)(Iriartea deltoidea) vines used as rope like mimbre or natural fibers like those from the Panama Hat Palm( Carludovica palmata).  The wood came from trees like  mangrove, mostly red mangrove( Rizophora mangle) and Salt tree( Conocarpus erecta) due to its  high content of calcium. Another vine used in construction was that one called Bejuco de Sapo or Toad vine which is actually the hanging roots of a hemiephiphitic plant.

Building on platforms of river stone was a solution to keep the home away from excess of water when it rained, not using mortar in between allowed the currents of air to flow free in between to keep the house cool..

Fish tailed palm or suita is probably one of the best materials to build roofs with. The palm has to be cut when the moon is waxing otherwise, it doesn t last long. If cut at the right time, it can last about 8 years. The inclination is also really important and it determines the durability of it. This is because the faster the water runs, the less that the palm is gonna absorb it, for this reason, an inclination of over 45% is important. The palm is overlaped using horizontal supports called ¨El tramo¨ , this supports are made from Chonta palm, cut  in long pieces along the trunk. This wood is extremly hard and it´s been used by locals to make beds and walls, and the indigenous people from the Amazon basin used them to make blowguns. This palm if used properly  is by far the best material to make a roof of, for the following reasons:

1.      Because it contains layers of leaves on top of eachother, It has perfect natural insulation, protecting from the sun radiation. The air flows free in between layers creating a constant circulation that keeps the inside of the building cool.

2.      Common roof materials such as thin roof or others made out of metal produce a lot of noise when it rains hard. Suita palm instead produces a nice relaxing sound.

3.      It s not visually agresive cause it blends in perfectly with nature, resembling the fur of a sloth.

Chonta palm is been used also to build and this is a tradition that comes from the first nations too. Walls, beds and ceilings are build with it, blow guns were also made by indigenous people from the Amazon basin.

The use of Caña blanca( Gynerium saggitatum) to make inside walls and ceilings is another practice that we inherited from first cultures, and this  fast growing plant is found near rivers and estuaries.  The plant is cut and placed after drying, some people treat it with a coat of barnish altough the use of bee wax mixed up with trementine is a more natural way to do it. The use of wax is still a common practice in Osa, Jicote or stingless bee wax is one of the best ones to use. The Guaymies would use it to cover their bags to make them waterproof and the locals still use it when fixing shoes, to make the sawing string go in easier.

Wood has  been in Osa the main material to build with cause it was easy to find due to the high percentage of primary of forest. A good example of this is the houses build by United Fruit Brands, and this is something I want to talk about with more detail later. The use depends basically on how hard the wood is, for example Manu( Minquartia guianense) by far the one of the hardest ones ever, and it used to make stilts when building on a steep hill. Locals place it right on the ground and not on concrete supports claiming that the it wouldn t rot due to it s hardness. Decks are also build with Manu as well as structural parts of the buildings or areas that are gonna be exposed to weather. Sura (Terminalia lucida)  is another hard wood used for building, the high content of calcium, up to 13% of the total mass when the is dried, makes  it really strong and resistant. One of the most popular and preciuos woods to build furniture or inside walls in the houses is Cachimbo( Platymiscium pinnatum) Cachimbo hediondo( Couratari scottomori), these are the equivalent to Mahogony wood which doesn t grow in the southern part of Costa Rica. Something that it is important to mention is that when cutting down trees, watching the phase of the moon was important since this would determine the durability of it.  The trees in Osa are cut down when the moon is waxing, if not, it gets damaged by insects that bore holes all through it. This is something that is still a mystery since it is hard to explain it scientifically, but we know so far that everything that contains water it s affected by the moon somehow including us, for example, when locals tap a tree to get the sap from it, they wait for the tide to come in cause the sap flows faster at this time, so cutting down trees at an specific moon phase might be close related to this fact.  I have seen pieces of Ron Ron (Astronium graveolans) full of holes from a beettle larvae, every hole about a half an inch in circunference, and this is true not only for this type of wood but for many other species including palm leaves from fish tailed palm( Suita). Some woods are known to repell the attack of insects naturally like the Amargo tree(Aspidosperma spruceanum), the high content of a bitter resin makes it not a tasty snack for termites which prefer to stay away from it, but locals take advantage of it  preparing a remedy with it to ged rid of parasites.

Amargo wood is medium to soft  thus it can not be used on exteriors, but it can be used on inside walls, or furniture.

One of the areas in Osa where the conditions are more extreme according to the Manohey tables is Palmar Norte y Sur. Divided by the Terraba river, the area is affected every year by floading during the rainy season ( mostly August, September and October). Rainfall reaches the 3000 (10 feet ) milimeters every year, humidity triggers the growing of lichens and moss in everything including Plycem, gypson and of course wood. Even metal grows lichens that eventually accelerate the corrosion process. The heat in this area s an important climate variable. During the day, more specifically from 11.00 am to 2.00 the temperature outside can reach the 35 C ( 90F ),and  if you add 93% humidity it can be really uncomfortable. Nevertheless, around this time of the day, there is a  breeze that blows at fairly constant speed, and this is something the engineers from the United Fruit Brands took advantage of, when building the houses for the workers. This houses are so far in the Peninsula the best example  of a succesful design on extreme climate conditions. Growing up in one of this buildings made always wanna wonder what made it so comfortable and fuctional even though they were so simple.

These building s are mostly built with the balloon frame house style, adding some victorian style to it.  Some of the woods used in the construction where  Cedro Bateo( Carapa guianense), Cedro Amargo( Cedrela odorata), on the walls and frames, and Manu( Minquartia guianense) on columns, beams and stilts. The boards used on walls had male and female connections and where about 12 centimeter wide which for the time was an innovative techique. The use of concrete was limited to the foundations and floors, allowing the building to have a proper in and out  temperature control by having very thin walls. Plus the houses have considerably wide openings( up to 40% of the total surface of the wall) to allow the prevailing wind to create a regular crossed ventilation. One of the interesting facts about this is that the houses weren t placed facing direclty Northwest or perpendicular to the wind but with  a turn of about 30 degrees from the horizontal, this causes the air to flow across the building from side to side at a constant speed blowing out the excess of humidity and cooling off the inside in the hotter hours. This is very important, most of all in places like Osa, excess of humidity causes different type of deseases on skin, like Carates( fungui infections) or sarpullido( skin rashes) in little kids, during the rany season dark humid places inside the building is like heaven for mosquitoes that cause Dengue fever, Malaria, Chagas desease as well as bacterias and viruses.

Color in this houses was something that also was  really well taken care of, most of them were painted with soft pastel color to increase the amount of light inside, and making at the same time the neighborhoods nice and pintoresque. Building on two storeys also made the building cooler on the first floor by having the second floor as buffer zone, this floor itself had a pretty high roof and ceiling( 2.70 mts or 9 feet)   with openings all around to let the hot air come out through the sides. Neting protection was also important in this openings to keep animals from coming in and nesting, like oposums, bats and doves.

 The worst pest for a long time were bats. This animals can trasmit bacterias that cause Leptospirosis through their excrement and the Amonia in it can ruin everything from wood to metal, acting like a very powerfull acid.

In places where the risk of floading was higher the house were built on stilts up to 2.4 meters off the ground leaving the lower floor as a parking area and bodegas. This way, if floading would reach the house, all the important parts of the house and it s belongins were safe from the water.

Spacing between houses( 15 meters, doubling the height of 6.5 meters ) allowed the currents of air to extract efficiently the air from the inside . This spacing also permitted the planting of trees, many of them brought in from Asia like Orgullo de la India( Lytraceae) or  like Caña Fistula ( Cassia fistula) originally from Guanacaste. Hibicus and Crotons where used as living fences creating a nice and colorful landscape instead of a colder and agressive one with barb wire fences.  

Planting fruit trees like Mangoes, Rambuttan, Papayas, was another common practice during the Banana Company times. Altough it provided the homes with delicious fruit during the season, on the other hand, it needed a lot of maintence cause the amount of fruit that fell on the ground. Some other types of fruit trees were brought in from places like Africa, Indonesia, Malasia and Tropical Australia. Bananas for example, are not originally from the American continent as many people think, the came from Southeast Asia and tropical Australia.

Altough theses practices were innovative at the time, right now with a world going through an ecological crisis, cutting down hardwood trees from primary forest to build is not the best alternative. Then, how can we apply the building concepts developed by the  Banana company architects without hurting the enviroment? Well, certified wood has proven to be an excellent alternative. In Costa Rica right now there are plantations of Teak wood ( Tectona grandis), Melina( Gmelina arborea) Pine(Pinus sp) Cipres( ) Pochote( ) al over the country. Wood plantations take CO2 and produce oxigen. A wood plantation looks better that a factory or a querry, and its building process doesn t  use as much electricity as building with metal or other materials that need electric tools.

Another material that is gaining popularity around the world is Bambu. This grass comes originally from Asia and grows at the amazing speed of 10 centimeters at day. The United fruit Brands also introduced Bambu to hold up the banana plants while they were fruiting so they wouldn t fall over. Nevertheless, this variety of it is not strong enough to build homes, and it s been only used to build temporary huts. Anyway during the last 20 years, Bambu caught the atention of constructors as a really good building alternative due to the high coast of other materials such as concrete, iron, steel and wood. Countries like Ecuador and Colombia have a long Bambu building tradition to the point that they even have bambu Shamans. Cutting down the canes it s a big ritual where they consider the phase of the moon and other conditions.

In Costa Rica right now is not hard to find Bambu to build with. Guadua obstusifolia is one of the most popular varieties to use for building, the canes are treaby ted with bromic acid to make them insect and wather resistant. As the Bambu cane loses watoter. it replaces it with acid, and after drying out, it is ready to be used. It is possible right now to find really good bambu in places like Pedregosito de Perez Zeledon. This small bussiness is run by costarricans, and it s been operating for over 10 years.

Bambu can be protected with bee wax or vegetable oil instead of using toxic two components substances such as barnish and others. Wood can be also protected with oil, this also gives the wood a really nice finish, cooking oil works really well, you apply three coats of it, waiting 24 hours in between aplications and then sand it off with Brillo to finish it up. Indigenous  people used plantas to treat wood and the Mayan used a substance that came from a caterpillar.

So as we can see, it is posible to find alternative forms of treating wood that are more enviromentally friendly. The most important thing while building in areas like Osa is to know the history of the material you are using, know where they come from, how was it extracted o made, how much energy the making proces took, how long does it last, and if can be reused. Consider the waiste water, now it is possible to find water treatment plants, sometimes the water can be reused for watering the gardens or something else. Collecting rainwater is a good alternative too, even in the dry season it rains at least once a month. Consider bringing the construction material from a ratio not bigger than 50 km or less, the less the better to reduce fossil fuel consumption. Overhang should not be les that 1.5 meters and roofs should have  45 degrees inclination.

 Consider the 4 R of sustainable arhitecture, , RECICLA, RECUPERA, REUTILIZA, RAZONA( RECYCLE, RECOVERS, REUSE, THINK) as the Architect Luis de Garrido puts it. Consider natural ventilation and light. This would not only save money but, it would be more healthy and it would make the materials last longer. It s been proven that a major cause of respiratory deseases at work is the air conditionig. Many of this people have to the hospital and then, that s a loss for the company. Natural light improves the absortion of vitamin D3 and then people are happier, they work better and they don t get sick as often. So sustainability is not only good for the planet, it is good for you, economically wise and health wise.

  In a world where architects worship themeselves building millions of dollars architecture, wasting materials and space, the need of a more social architecture becomes important. While some architects are busy proving to the world how great their architecture is, millions of people in different places don t even have a place to live. It is important to understand that architecture is born to fullfill a needing, the need of comfort, the need of protection against the climate and the potentional harms that sorround us. The moment the human being takes bone and skin of animals and builds a hut, is doing architecture. Even tough it developed into an art we should never forget that in the end, it is for the human being.

In our country every year natural disasters leave people homeless all over the country. People build, and they make the same mistakes over and over again, cause they don t have the money to pay architects. We need architects for the poor, basic information about how to build properly can make the life of them better and at the same save lives.

Sutstainable architecture should not be only for the rich, should not be just a style that is cool to have, sustainability should be part of all of us regardless we are rich or poor, black or white, there is not such a thing as retro architecture, or minimalism, or maximalism, deconstructivism, architecture is only one, one architecture for the human beeing.

Questions or commnent about sustainable architectcture or construction please forward to:

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