What is a bioclimatic house?

Today we would like to talk to you about what a bioclimatic house is and what it consists of.

What is daily life like for someone living in a home that functions thanks to its surrounding environment, reducing energy consumption and harnessing natural resources to generate the necessary energy?

In fact, the moment we consider building a house—if we have a certain ecological or health consciousness—most of us go online to search for information on ecological and passive houses. It is precisely at this moment that most clients arrive at our studio immersed in a sea of doubts.

To try to clarify these doubts and understand what a bioclimatic house is, today we are dedicating a post to defining its operation and characteristics, so that all of you who have decided to build a bioclimatic, healthy, and natural home are clear about the foundations upon which these types of dwellings are built.

What is a bioclimatic house

A bioclimatic house is a dwelling capable of maintaining an appropriate and pleasant indoor temperature using only the natural resources of the environment while avoiding conventional energy sources.

This is achieved by capturing heat and sunlight and subsequently storing it in construction materials, as well as through thermal insulation.

Climate adaptation

To achieve a suitable indoor temperature without the need for external energy for climate control, it is important to understand the climate and use different strategies according to our location.

In this regard, orientation, insulation, and ventilation must be taken into account.

Orientation

Orientation is one of the first premises we should verify before building a house. It is important to be able to capture solar radiation to heat our home naturally.

In the northern hemisphere, where we are located, the best orientation is south, as it is the direction that receives the most hours of sunlight per day and at the highest intensity. For this reason, we must take advantage of it and place a large glass surface on the south facade, which could account for around 75% of the total facade area.

With such a large window surface, we could experience overheating inside our home during the summer. It will be necessary to protect ourselves using porches, pergolas, or solar filters that provide shade and prevent radiation from entering.

In other orientations, we must naturally decrease this percentage because, just as we gain heat through windows, we also lose it. Especially on the north-facing facade, we should have little glass; if it is necessary to have openings to the north, we must ensure the glass is double or triple-glazed with insulation so that we do not lose the heat generated inside through a facade that is continuously at a low temperature.

If the land we are on has a slope, it is best if it faces south. This way, we can work with a very open facade and capture solar radiation.

Furthermore, it is possible to take advantage of one of the essential characteristics of the ground: thermal inertia, defined as a material’s capacity to store heat. This implies that the earth is capable of regulating and reducing heat exchange; in fact, if we were to dig a well, we would see that at a certain depth, the temperature remains relatively constant throughout the year.

Thus, if we semi-bury part of the north facade, for example, we will ensure that the heat we have captured inside our home is not lost.

Since we want to minimize the consumption of climate control systems—air conditioning, heating, etc.—capturing heat is important, but so is keeping it inside our home once captured.

Thermal Insulation

Insulation is another topic to address to understand what a bioclimatic house is. Its thickness is one of the aspects that differentiates a bioclimatic house from a conventional house today.

Currently, a dwelling is considered acceptable if the facade insulation is between 8 and 10 cm thick. However, in the case of a bioclimatic house, the thickness of the thermal insulation will be in the range of 15 to 20 cm, depending on the specific area where we are located.

On the other hand, it is not only important how much insulation we place, but also that there are no thermal bridges. A thermal bridge is a specific point in the house where the insulation loses its continuity.

This occurs when construction details are not well-resolved, which was common in 95% of the homes built in the pre-crisis era, where the developer’s economic profit was prioritized over the construction and climatic quality of the dwelling. One or several points on the facade lacking thermal insulation continuity can be a serious error, as it will facilitate heat-cold exchange between the exterior and the interior of our home.

Ventilation

While we have managed to heat our house and keep the heat inside so far, we also need to know how to cool our house. We will do this through ventilation.
We know that an air current of just 3 meters per second—10.8 kilometers per hour—manages to reduce the thermal sensation by approximately 1°C.

In a way, it seems easy and simple, but the windows must be positioned so that there are no obstacles or walls preventing this path.

For this reason, we often use interior courtyards that can offer an outdoor space through which to ventilate bedrooms or other rooms. In the Mediterranean climate, courtyards work quite well as they manage to create an outdoor area that is somewhat more controlled than the open exterior.

Energy and economic savings in a bioclimatic house

In the definition of what a bioclimatic house is, it is necessary to consider the energy savings achieved with this type of construction, which in general can easily reach 80% or 90% savings compared to a conventional dwelling.

Furthermore, in a bioclimatic house, we can even reach zero consumption. By generating our own energy, we can stop depending on gas or electricity utility companies, preventing our house from consuming energy for climate control and obtaining energy independently. In other words, we can build a self-sufficient house.

Materials

Of course, if in describing what a bioclimatic house is we have said it is essential for it to adapt to the environment, the materials we use should also be local whenever possible for the sake of consistency. By using local materials, we support production in our area and save on the transport of materials or systems.

In general, for the wall system, we will work with natural materials such as wood, ceramic, or stone materials that have manufacturing processes with a reduced ecological footprint.

Ceramic or stone materials have a great capacity to store heat obtained from the sun. On the other hand, wood—while being a material more similar to an insulator and not accumulating heat—is a material that allows us to work in the workshop to the millimeter and control the on-site installation, resulting in very insulated and airtight houses. Additionally, it is a lightweight material whose structure is easy and quick to assemble.

Among the benefits, it is also worth noting that it helps regulate indoor humidity. As wood is a porous material, it captures excess ambient humidity and releases it when the indoor relative humidity level is too low, generally when we turn on the heating and the environment becomes dry.

In the definition of what a bioclimatic house is, it is necessary to consider the energy savings achieved with this type of construction, which in general can easily reach 80% or 90% savings compared to a conventional dwelling.

Furthermore, in a bioclimatic house, we can even reach zero consumption. By generating our own energy, we can stop depending on gas or electricity utility companies, preventing our house from consuming energy for climate control and obtaining energy independently. In other words, we can build a self-sufficient house.