This residence in Calonge integrates respectfully into the natural topography of the site, organized into distinct volumes that maximize comfort through bioclimatic strategies ensuring exceptional conditions of light, hygrothermal regulation, and natural ventilation.

SITE IMPLEMENTATION

This sustainable home located in a municipality on the Costa Brava is situated on an elongated plot with a pronounced slope.

Based on these premises and with the objective of achieving proper site integration, reducing the landscape impact of the dwelling and ensuring excellent connection between interior and exterior, a division of the program into distinct volumes is proposed, so that each is placed in a staggered manner, adapting to the natural topography of the terrain.

Thus, three volumes are proposed that will contain different programs and will be connected through a series of intermediate spaces that function as multipurpose areas and facilitate flexibility of uses.

Furthermore, the intermediate spaces have the capacity to modify their function through a system of complete opening and closing that allows them to become interior or exterior spaces depending on the climate throughout the year or the use of the house at any given time. These are spaces that can become cool summer porches that not only extend the living spaces outdoors but also promote natural ventilation of the rest of the house, or transform into bioclimatic galleries in winter, capturing and storing solar heat and gaining climate-controlled living spaces or winter gardens that temper the entire house and complement natural air renewal without thermal losses.

This strategy takes on special relevance on a plot with longitudinal development whose south orientation is limited and where we seek this relationship with the exterior that is not only reduced to the classic front garden but extends throughout the entire dwelling, intensifying this fantastic relationship with the outdoors that we have in a coastal Mediterranean climate.

PROGRAM

Access to the dwelling is from the lower level, from where we can access the vehicle garage, which connects directly to the interior of the house, or a pedestrian exterior staircase designed to receive visitors without invading the privacy of the outdoor spaces.

From the parking area, the program progresses from more public to more private throughout the three volumes that define the dwelling. In the first volume, the living areas are located in direct relation to the outdoor garden and pool space and with connection through the intermediate relational space to the dining and kitchen areas, which are located in the second volume.

The garden and pool space is in a privileged area of the dwelling, a large practically flat space located at a low height in relation to the street, but which ensures absolute privacy from it and with exceptional views over the sea, taking advantage of the fantastic location of the dwelling on the Costa Brava.

From here, and already ascending one level to adapt to the slope and after crossing a new intermediate relational space, we find the most private bedroom area, which also enjoys exceptional sea views, being located on a higher level than the rest of the house.

This bedroom level is complemented by the upper area of the kitchen and dining module, where we find the master bedroom that includes a remote work area with privileged views.

In all volumes, the best south orientation is always reserved for living and resting spaces, locating the wet areas of bathrooms and services in the coldest north-facing areas, so that we ensure comfort naturally through solar control in the main rooms and generate service spaces as thermal buffers that reduce energy losses.

BIOCLIMATIC STRATEGY

Having ensured solar capture in all the main rooms of the dwelling, the first strategy is based on achieving good solar protection in summer, which is achieved through adjustable wooden slats that guarantee indirect light, preventing direct sunlight and interior overheating and allowing natural ventilation of the room.

The second strategy is always thermal accumulation, whether heat in winter or coolness in summer. This is achieved thanks to dense thermal mass walls that are protected on their exterior face with a high thickness of insulation, so that the wall captures and stores heat in winter, well protected by exterior insulation that prevents thermal losses, but also stores coolness in summer when solar protection prevents overheating of interior rooms through glazed openings and exterior insulation prevents heat transfer through walls.

This thermal operation that combines thermal mass in walls and exterior insulation together with high airtightness in joints that reduces thermal losses achieves a reduction in energy demand while ensuring maximum comfort naturally. This not only avoids artificial climate control during most of the year but also ensures a healthy interior environment at adequate comfort humidity and temperature that buffer exterior conditions naturally, avoiding excessively dry environments derived from excessive use of air conditioners or heating systems that dry the environment, diminishing the natural defenses of our organism.

Finally, it is essential to ensure cross ventilation to improve thermal comfort during the warm months. This is achieved by creating opposing openings in cool and warm facades to generate a differential pressure that promotes air circulation. By working with separate modules, this principle is perfectly fulfilled in each of the rooms and enhances the thermal sensation of the entire space.

CONSTRUCTION SYSTEM

The dwelling is built based on a system of load-bearing walls of thermal clay brick that are insulated on their exterior face with a natural and breathable ETICS insulation system, protected with a final lime render. This is a system that ensures adequate interior thermal mass—temperature accumulation—and excellent exterior insulation to prevent thermal losses and guarantee total control of interior comfort temperature.

It is important to highlight the importance of having natural and breathable insulation that prevents condensation and moisture and is installed in thicknesses of between 12 and 15 centimeters to ensure passive operation and zero energy consumption.

The floor slabs are carried out using a unidirectional system of prefabricated semi-joists and ceramic blocks, a conventional system with excellent structural results and which has the advantage of being able to be left exposed, something that not only has an aesthetic function but also improves acoustic performance and reduces reverberation inside.

The final finish both inside and outside is proposed in earthy tones to reduce the landscape impact in a natural environment on the Mediterranean coast and highlighting the natural and low-impact materials with which the dwelling is built.

Local suppliers who fire bricks with biomass energy that avoid the use of fossil fuels throughout the process are prioritized, reducing the ecological footprint of construction.

ACTIVE SYSTEMS

As this is a passive house that takes advantage of bioclimatic strategies to reduce cooling and heating energy demand by around 80 or 90% for most of the year, active energy generation or hot water systems are reduced to a minimum, reducing their maintenance and renewal and managing to cover practically 100% of energy demand through renewable sources with photovoltaic solar panels installed on the roof.

– AIR RENEWAL

Complying with recent building regulations in our country, it is necessary to have mechanical extraction that ensures that interior air is renewed when the dwelling is in use.

To avoid exchanging air directly with the exterior, which would mean assuming thermal losses, but also not resorting to complex air renewal systems with heat recovery with limited maintenance and useful lives, we resort to a natural renewal strategy through the bioclimatic galleries distributed among the modules that make up the project. This is a solution that greatly simplifies installations and allows ensuring natural tempered air renewal at low cost, making the most of the privileged Mediterranean climate in which the dwelling is located.

The air is preheated by the action of the sun on the glazing and this heat is stored in the gallery and can be introduced into the interior rooms, either by direct opening of windows or doors or through air vents or micro-ventilation. So that the extraction of air from bathrooms and kitchens draws fresh outdoor air that enters the dwelling already preheated, ensuring exceptional air quality not only in terms of CO₂ but also reducing the presence of contaminants from dust or other microorganisms or toxins present in the home.

– HOT WATER GENERATION

Hot water is the main energy demand system of the dwelling, so a simple aerothermal system is proposed that will accumulate water in a thermal storage tank, which allows accumulating the water heated thanks to solar energy for hours and minimizing the demand for grid electrical energy.

– WATER MANAGEMENT

A rainwater collection tank is installed, which can eventually be supplemented with gray water from showers and sinks, which accumulates water for irrigation and exterior cleaning use.