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A bioclimatic house is a building whose architectural construction is designed to harness natural resources to meet the climatic needs of its inhabitants, thus avoiding the consumption of conventional energies.

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How does it work?
For a house to function in a bioclimatic manner, a heating, cooling and ventilation system needs to be set up. There are a number of techniques, which vary depending on the type of house (detached, semi-detached or in a flat), the climatology of the place, the architectural design and the budget.

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Several aspects have to be taken into account when building a bioclimatic house:
-Orientation: it should be north-south, which gives the guarantee that the sun will warm the house throughout the day. The rooms that are used less (kitchen and bathroom) should be located in the northern part of the house. The rooms that are most used (the living room and dining room) should be located in the south and the bedroom in the east. The house must also have interior courtyards for natural ventilation.
-Greenhouse effect: this consists of installing large windows in the southern fa�ade to heat up the rooms. The best way to generate cold air is to use the north-south cross-ventilation system.
-Walls: heat and cool air are best conserved with thicker thermal dividing walls.

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These constructions also harness other clean energies, such as biomass, solar energy or wind power. Solar panels can be installed to generate electricity or thermal panels to heat water.

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Energy savings
Bioclimatic architecture enables households to save between 60 and 100% in energy consumption compared to a conventional house, according to the Centre for Energy and Environmental Technology Investigation (CIEMAT). The annual saving has been calculated at around 1,000 euros.

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The constant temperature and lack of abrupt changes increase the comfort and quality of life of the inhabitants of these houses: natural ventilation does not dry or pollute the air, reducing allergies, asthenia and migraines that are often caused by conventional air conditioning systems. Finally, the harnessing of solar radiation enables inhabitants to enjoy greater natural illumination, which is also healthy.

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Cost depreciation
Building a bioclimatic house in Spain is not easy. They currently number between 500 and 1,000, according to CIEMAT. The main disadvantage is the possible higher costs of construction. However, CIEMAT points out that the cost of these buildings is usually comparable to that of a standard house or, at most, 10 to 12% more expensive in terms of materials (glass and isolating materials). This initially higher cost is recovered in some three or four years, however, thanks to the energy savings involved.

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Other difficulties are finding an experienced architect and builder and also locating a spot with the correct orientation (north-south) in large cities.

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Subsidies and other initiatives
The authorities do not provide subsidies for this type of building, but there are several local initiatives to promote their construction, such as those offered by the Autonomous Communities of Navarra, Catalonia or Castilla La Mancha.

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Did you know...?
-Buildings and construction account for 60% of the cosumption of materials and energy and half of the waste and contamination produced on the planet, according to the Worldwatch Institute of Washington.

-Spanish buildings emit some 31.3 million tons a year of CO2, the gas responsible for climatic change.

- Navarra has started up a project known as the bioclimatic town of Zolina, a housing development of 1,000 dwellings, which will be self-sufficient as far as energy is concerned. Additionally, another 4,600 bioclimatic houses are being built in Sarriguren.

-In Barcelona, the Municipal Housing Council has just handed over the� final few houses of a pioneering project to build 431 bioclimatic flats for youngsters. The promoter guarantees (via contract) a saving of 60% in energy needed to heat up water.