Reduce energy consumption with a bioclimatic house

One of the great challenges facing the construction sector is to meet the requirements set out in the DIRECTIVE 2010/31/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 19 May 2010 on the energy efficiency of buildings. The implementation of these guidelines translates into a change of model. Traditional design and construction processes are necessarily called into question and altered. A paradigm shift is therefore necessary: moving from the conventional (inefficient) house to the bioclimatic house.

Principles of the Directive

The Directive, in its article 9, establishes that the Member States of the Union commit to carrying out actions and national plans to ensure the following:

• That by 31 December 2020, all newly constructed buildings must be NZEB (Nearly Zero Energy Buildings).

• That by 31 December 2018, existing public buildings must also be NZEB.

The Directive stipulates that energy must be used "efficiently, prudently, rationally and sustainably". Given that 40% of total energy consumed in the European Union is due to buildings, and as the sector is a continuously growing one, energy consumption must be limited (by building efficient buildings and promoting the use of renewable energies).

In points eight and nine of the Directive, it is emphasized that measures implemented to increase the energy efficiency of buildings must take into account climate conditions, local particularities, indoor environmental context, and cost-effectiveness. It also stresses the importance of implementing passive conditioning systems (air conditioning and heating) to the detriment of current systems (which are responsible for a large part of the energy bill). Similarly, it highlights shading and the quality of indoor air in spaces. For all intents and purposes, it promotes construction based on the bioclimatic house.

What is a bioclimatic house?

A bioclimatic house takes into consideration the climatic conditions of the location to get the maximum benefit from available natural resources (solar energy, vegetation, rain, wind). In this way, it minimizes the environmental impact that the use of buildings generates, as it reduces energy consumption. Likewise, it also invests countless efforts in achieving maximum thermal comfort, maximum natural lighting, and high-quality indoor air free of pollutants (due to adequate ventilation and the absence of synthetic construction materials causing the emission of toxic substances).

Principles of bioclimatic architecture

Bioclimatic architecture seeks maximum thermal comfort with minimum energy expenditure. To achieve this, the following aspects are taken into account:

• Climate and environmental conditions (rainfall regime, solar radiation, humidity, vegetation, air currents...). Local particularities are considered to make the most of natural resources.

• Design and geometry of the building. It starts with a well-studied design and geometry that adapt to the land and good orientation.

• Materials. Natural and indigenous materials are used, thereby minimizing the environmental impact both during the construction phase and during the use of the building itself.

• Solar energy. Efforts are made to maximize the use of solar radiation in cold climates.

• Natural lighting. A detailed study is undertaken to maximize the use of natural lighting.

• Construction solutions. Detailed study of construction solutions that may entail energy savings (such as the construction of thick walls to increase thermal inertia).

• Solar protection systems. The installation of protective systems (vegetation, eaves, awnings, pergolas...) is foreseen to avoid overheating.

• Thermal insulation. It is based on the traditional passive thermal principle. In this way, it increases the thickness of thermal insulation in the envelope to minimize energy loss through unwanted air leaks. Natural insulators like air (air chambers of the facades) are also taken into account.