Architects: Espegel - Fisac
Location: 28400 Collado Villalba, Spain
Project Year: 2010
Photographs: Joaquín Mosquera
From the architect. The Ants' House is formally conceived considering the surrounding environment and its location on a large plot in the Manzanares Park, immersed in the mountains near Madrid.
The house is meant to dominate the vast natural world which lies beyond its entrance. Its shape is designed by nature. Just like an outstretched hand, the house works its way through the almond trees reaching out from in between the branches, reaching towards different spaces and lights effects. Its location, on the southern slope of the mountains, gives the house favourable climatic and environmental features. The climate of the mountains of Madrid, with mild Winters and pleasantly warm Summers, combines cold temperatures with plenty of sunshine during the Winter and cool nights in the Summer, making it an ideal location for bioclimatic design.
The location, combines two basic conditions: proximity to an urban centre and ease of access, as well as the pleasure of the mountains and the natural surroundings. Dualism is also present in the house: nature vs man-made.
The house is a two level building with a concrete staircase located in a central position. The ground floor, which adapts to the sloped ground through a wide ramp, is a large open space which has different functions: a reading zone, a fireplace, a socialising area, an outward view towards the patio, a service area which comprises the kitchen, as well as the laundry, storage and facilities. This single space extends as far as the South Terrace, it borders with the swimming pool and a large almond tree, and eventually ends under the span of a concrete slab, in a covered outdoor dining area.
The first floor, built over part of the lower one, hosts a guestroom in the cantilever over the outdoor dining area, a bedroom for the children with a large playroom, and the master bedroom with a mezzanine which creates a canopy over the bed and provides a view over the Northern mountains. Lastly, the great spanned structure, is closed by a concrete slabs and walls, wrapped in a translucent glass skin protected from the western sun by aluminum slats.
Because of its shape, the house acts as a "solar funnel" with a high degree of passive solar collection, with openings towards the South and West, whereas the more contained size and profile facing North prevents excessive heat loss, typical of this orientation. The southern sun, warm in the Winter and harmless in the Summer, is what the building captures most. The western sun, less intense and milder in the Winter and horizontal but hot in the Summer, is controlled by tiltable external sunshades.
During the Winter the heat intake is achieved by direct solar gain in areas with a southern exposure, and by the indirect contribution of solar collectors on the roof as well as floor heating in the internal zones. During the night maximum insulation is required from the glazing, this is achieved by enclosing its perimeter with velvet curtains. Extra power support is provided by a gas boiler and a fireplace located in the reading area which can benefit from this radiation.
In the Summer, intense southern sun is screened by protecting the façades with the upper floor cantilever, and the Western façade is protected by adjustable horizontal aluminum slats on a swing frame. The inside temperature is lowered by using Gravent type windows, which provide permanent cross ventilation: they are installed in the upper parts of the glass panes in the living room and master bedroom. The system can extract heat and cool off the roof during the Summer months, while the large blade fans, hanging from the concrete slab, work at low speed to unlay the hot air in the Winter and provide cool in the Summer. The insulation of the wide terrace surface is obtained by a permanent vegetative cover, which reduces the heat of the sun by evapotranspiration.
The property has a radiant floor heating system with zonal thermostatic regulation: the main contribution comes from the solar energy captured over a 16 m2 area of vacuum tube collectors. The energy for radiant floor heating is stored in a 750 litre tank with double insulation, with an additional 300 liters for hot water [ACS]. Further heating support consists in a natural gas mixed-use boiler.
In absence of occupants, solar heat is primarily used to temper the space and maintain the fixed temperature setpoint. This heat will circulate through the radiant floor as long as the storage temperature is at 30 °C or until it falls to 25 °C. When the temperature exceeds the interior setpoint, circulation will be deactivated, producing an increase in the accumulation temperature up to 50 °C. Whenever the accumulation temperature exceeds the temperature limit, heat is redirected to the swimming pool which is equipped with a thermal cover to prevent temperature loss. This allows the bathing season to be extended by at least two months before and after the Summer, and also increases the life of the collectors.
The blind façades of the house have been wrapped in an outer layer of stadip 5+5 mm glass with translucent butyral held by a horizontal steel substructure fixed to the reinforced concrete walls or to the light cellular concrete blocks using anchorage elements which create a vertical ventilation air chamber. The insulation used in these walls is an 8 cm rock wool layer plugged to the outside of the 30 cm concrete wall.
All The carpentry and glazing have high insulation and low emissivity properties. The insulated carpentry has been provided with the Climaplus (8/16/5+5) double glazing, which consists of an inner Planitherm layer and an outer Planilux layer and an argon gas filled air chamber. Coloured glass has been used in some cases, as in the entrance hall and the courtyard, to convey a sense of artificiality.
Due to the large glazed areas of the house, a heavy structure of reinforced concrete walls and slabs was chosen to achieve high thermal inertia throughout the building: this, together with the concrete floor, increases the efficiency of floor heating. No cooling system has been necessary thanks to the correct bioclimatic design.
The architecture of the house spreads over the plot using small, low intensity settlements: lightning sticks provided with photovoltaic cells, large circular flowerbeds, insulated flooring concrete circular slabs resting on natural ground, wood staircases, which give rhythm to the natural surroundings.