House in Monte el Pardo
WORKING AS INTERNATIONAL COLLABORATORS, THIS FAMILY SPENDS A GOOD PART OF THE YEAR ABROAD, SO THEY ARE LOOKING FOR A REFUGE WHERE THEY CAN SPEND HOLIDAY PERIODS NEAR THEIR LOVED ONES AND WHERE THEY CAN ONE DAY RETIRE.
The chosen location is the Sierra de Madrid, near Monte el Pardo, about 30 kilometers from the city center, where they found a plot with fantastic views and orientation. Our clients anticipate that their house will be empty for a good part of the year, so they want to find a way to monetize it by renting the property when they are away, while still maintaining a private space.
Thus, the commission began as a dwelling with two independent zones that could be combined into one in the future. The sloping terrain helps us address both needs by creating a two-story house with independent external access to each level.
In this way, entry is made from the first floor via a walkway that overcomes the steep slope of the initial meters of the plot. On this upper floor, we find a suite bedroom and another bedroom with a bathroom, with the possibility of dividing it into two individual bedrooms.
Furthermore, this floor can be completely independent of the ground floor. It houses the living-dining area, the kitchen, and a small study that can be converted into a bedroom, all in complete connection with the outdoors.
BIOCLIMATIC STRATEGY
As it is a compact two-story house, we sought to ensure good lighting, sun exposure, and ventilation in all rooms through two courtyards on the north and south sides of the dwelling.
The south courtyard of the house is key to ensuring good natural ventilation without incurring energy losses. It is a double-height courtyard with a south-facing facade and a glazed roof that can be opened or closed depending on the season.
In winter, the glazing remains closed, creating a greenhouse effect that preheats the natural outdoor air. As it is a double-height courtyard, we consider that the stratification of warm air will displace it upwards. From there, we introduce it into the house using CO2 sensors that activate fans located in bathrooms. These absorb and renew the air whenever the house is occupied.
In summer, the glazing opens completely, and ventilation is achieved through a Canadian well. This is a tube about 30 meters long that runs beneath the house at a depth of one and a half meters, introducing air into the dwelling at a temperature between 15 and 20 degrees during the warmest months of the year.
Additionally, in summer, it is possible to dampen the floor of the south greenhouse courtyard, which is made of porous paving and contributes to improving the thermal sensation of coolness.
We have good solar capture with a clear south orientation of the facade, which opens with glazing and solar protection to capture or shield from the sun depending on the season. Furthermore, the longitudinal shape of the dwelling allows us to utilize the north facade to generate cross-ventilation in all rooms on the upper floor. On the lower floor, which is semi-buried, ventilation is ensured thanks to the courtyard on the north facade.
Air renewal is carried out through the courtyards so that the air is introduced indoors at a temperature higher than the outdoor temperature. This contributes to reducing energy consumption for renewal without the need for complex forced mechanical ventilation systems with heat recovery.
It is important that the air circulates under normal conditions, meaning without the need to pass it through complex machines or filters. These not only alter the ionization quality of the air but can also add harmful agents if the ducts are not properly maintained or are made with thermosensitive plastics.
Furthermore, the project not only considers air renewal but also the quality of the indoor environment itself, avoiding all types of finishing products that contain toxins emitted into the indoor air as volatile organic compounds (VOCs). These diminish air quality, and even in small quantities, due to continuous and long-term emission, they generate a bioaccumulation effect in the organisms of people and animals inhabiting the space. This is why all types of varnishes, glues, and paints are avoided throughout the house.
CONSTRUCTION SYSTEM AND MATERIALS
We opted to combine a hybrid system that allowed us to save costs while ensuring comfort according to the use of each area.
The ground floor, which is semi-buried and in contact with the ground, is designed with a concrete block inertia wall system that functions as both a foundation and a wall. This plinth, which forms the entire ground floor, is topped on the first floor with a semi-prefabricated light timber frame structure made of spruce pine wood with sustainable management certification and PEFC chain of custody.
A perimeter beam is placed on the concrete block wall, acting as a frame, and a sleeper where the wooden beams rest. These, in turn, support the light-frame floor slabs, which are completed with a layer of sand that improves the acoustic performance and thermal inertia of the assembly.
The facade structure is composed of a framework of laminated pine wood battens, protected on its exterior face by OSB panels and on its interior face by glue-free gypsum fiber panels. The OSB conglomerate panels are manufactured in the factory. Their development is fully in line with the demand for organic ecological materials, using resin as a binder to fix the strands.
Insulation is applied from the exterior using a wood fiber SATE system with low thermal conductivity and vapor permeability, reducing the risk of condensation and humidity. This eliminates thermal bridges throughout the envelope and improves comfort thanks to natural temperature gain on the south facade.
Interior divisions are made with clay-coated cellulose Fermacell panels, floors with handmade terracotta tiles, and all enclosures are made of wood. Clay is a natural material with multiple properties, notably its ability to absorb odors and its high hygroscopicity. Hygroscopicity is a quality that allows it to naturally regulate humidity, absorbing or releasing water vapor depending on indoor environmental conditions.
FACILITIES
As the energy demand study indicates that due to being located in a cold climate zone and at a certain altitude, we have a high heat demand in winter, and a heating system might be necessary during certain weeks of the year. Thus, a water radiator heating system is prepared, which can easily supply the remaining energy demand during the coldest days of the year.
Additionally, a wood-burning stove is installed, purchased second-hand by the clients themselves, perfect for peak demand thanks to its power and its operation using a renewable energy source like biomass.
The electrical installation is carried out in a star design with halogen-free wiring. Furthermore, precautions are taken to avoid wiring in any long-stay areas such as bed headboards, and bioswitches are installed in each room of the house to interrupt the power supply during nighttime rest hours, eliminating any type of electric field.
To maximize water resources, an 8,000-liter rainwater harvesting tank is installed to store rainwater for cleaning and toilet use.
Photographs: Salva López
MÁS SOBRE House in Cerros de Madrid
