House in Lège, by Anne Lacaton and Jean Philippe Vassal

Architects Anne Lacaton and Jean Philippe Vassal were asked by a brother and sister to build for them a holiday house on land they owned on the Atlantic coast of France. A key condition of their request was that the project should respect as much as possible the 46 trees – some up to 30 metres in height and over 80 years old – that grew on the site. The result was a dream come true; the dream that every child has, and keeps, of having a house in the trees.

The landscape
The site - located in Lège, west of Bordeaux - was one of the last in an area facing the Arcachon Bay Nature Reserve still not built upon. Sloping down harshly to the bay, the landscape consisted of 15 metre dunes covered with pine trees, shrubs and mimosa with views to the Island of Birds.
Despite their youth, the brother and sister (only 23 and 25 years old, respectively) had already learned to appreciate the beauty and the fragility of the land. Both were conscious of the harm that the neighbours had caused when building their own houses. All had cut trees and disturbed the landscape of dunes by moving earth, hollowing foundations and raising breezeblock walls.
It was through their father, an artist and a teacher of plastic arts at the Bordeaux school of architecture, how the siblings met Lacaton and Vassal. They spoke to the two architects about the beauty of that site - a site where the whole family used to picnic during the summer months; a site where they, as children, used to make huts between the trees. It was also during this first conversation that they voiced their concern as to how to build a house without destroying the charm of the plot, bearing in mind that some of the shrubs on the site were over 3 metres high thus prevented any view over the bay. Furthermore, local planning regulations required that their building had to be at least 4 metres from the neighbours and 15 metres from the shoreline - all of which meant that the house should be located just behind the crest of the dune.

Adding instead of replacing
Lacaton and Vassal began their response by acknowledging that although it usually seemed most comfortable to live on the ground, the analysis of the situation led them to a solution where they imagined a house in amongst the trees; a house that would be floating above the ground.
Faced with such an unconventional project, the clients nonetheless decided to have faith in the architects and to begin construction. As soon as they climbed onto the newly built platform, they realised that it was the right choice: from the 210 square metre concrete slab floor, one could enjoy a stunning view over the bay.
In order not to spoil the dunes, the foundations consisted of twelve micro-piles rammed eight to ten metres into the ground. On top of them, a galvanised steel structure was assembled on piles of variable height - depending on the slope of the ground - which allowed for a passage underneath the house. The insulation both underneath and on the sides of the house was protected from the seaside environment by a layer of corrugated aluminium sheeting. Since the corrugation laid perpendicular to the bay, the aluminium sheeting echoed the glitter of the water and illuminated the space beneath the house, creating an artificial sky.
Another consequence from the strict respect for the existing vegetation, was that six pine trees perforated the house. To enable the trees to move with the wind, while at the same time keeping the house completely rainproof, a rubber collar fastened the trunks to skylights. These skylights were Plexiglas plates tied to the roof of the house by elastic belts that allowed them to slide following the movements of the trees. The result was that the trees can almost be mistaken for the structure, appearing like symbolic pillars of the house.
By building a house around the trees and allowing the trees to live within the house, architecture and landscape come together.

Photos: Philippe Ruault
Captions for illustrations:
a. Architects Anne Lacaton (1955) and Jean-Philippe Vassal (1954).
b. Section and plan of the House in Lège (1998). From a wide balcony that acts as an extension of the living room, one enjoys a stunning view over the Arcachon Bay.
c. An automatic irrigation system monitors the soil humidity of the dunes underneath the house.
d+e+f. The windows in the aluminium facades are made of corrugated transparent plastic sheets, but the main facade overlooking the Bay is made entirely of large transparent glass sliding doors.
g+h+i. The architects conducted a study in collaboration with the French agricultural authority to ensure that the trees going through the house were not endangered by the project.

House in Baião, by Eduardo Souto de Moura

The Portuguese architect, Eduardo Souto de Moura, received a commission for a small house from a couple with two children, which would be built by the river, Duoro, set in the Baião hills. The client wished the house to have the character of a shelter used for weekends and requested that the existing ruins on the site would be the starting point for the project.

Between nature and the artifice
A ruin can be understood as the edge between architecture and nature. In other words, the moment when a construction ceases to be architecture and becomes nature. The work of Souto de Moura shows an interest in this dialectic between nature and artifice. A dialectic where the building site changes into a tool, it becomes a mental and an intellectual exercise in itself.
This sensitivity towards the site goes hand in hand with the belief in simplicity as a means to transmit thoughts. Following the words of the poet, Eugenio de Andrade, "... only the exact word is of public interest...", Souto de Moura believes that the tools used by the architects to write - with materials such as stone, iron and glass, as well as their joints, which are of no less importance - have as their final goal to create an anonymous and serene work in relation to time. In other words, to become poetry and to arose feelings.
Architecture of high complexity based on its contextual textures is, however, a consequence of this simplicity in the use of materials and its joints. It was inherent in the profound integration with the site, of camouflaging new spaces with nature, of fusing borders, underlining characteristics and expressing judgements of all the surrounding elements.
The ruin becomes important when understanding it as a division which defines the limits, as a fundamental element of spatial definition and of obtaining a concept of time. It maintains a dialogue with the context where it is placed. It is an architecture that is not forced, a silence where nature is seen as architecture and culture as nature.

The ruin Wall House 1990 - 1993
Responding to the wishes of the client, the ruin of the old farm which was attached to a retaining wall became interpreted as a kind of a bridge between internal culture (of the inhabitant) and an external reality (of time). The work began with the demolition of the retaining wall of big granite stone blocks, a traditional material of North Portugal. This was followed by the movement of earth, shaping a "negative" of the house in the ground and the old ruins began to take the form of a sort of a closed garden that served as a entrance hall for the house. This was a second building which consisted of a concrete box which was supported by the ruin and inserted into the earth. In this way, the ruin served as a joint between the past and the new rectangle house which, because of being partly set into the earth, was 'blind' on its side walls except the front facade which opened towards the river, Douro. From the interior, next to a fire-place built of stones from the old retaining wall, one could enjoy a view to the far away valley of Cerdeira through the glass facade.
The simple programme of the house is laid out in one level under a grass roof which forms part of the topography of the place. Being faithful to the concept of the ruin ceasing to be architecture and becoming nature, the house is camouflaged by the landscape in such a way that it is not the trees' foliage which acts as a second skin but the landscape itself.

Photos: Luis Ferreira Alves
Captions for illustrations
a. Eduardo Souto de Moura (1952), architect.
b. The family asked for a house of minimum dimensions to spend weekends by the river Duero.
c. The access to the house is through a garden inside the ruin.
d. The glass facade goes above the ceiling. This construction detail makes the only facade of the house to be perceived as a tensed plain of glass and aluminium, parallel to the old granite walls.
e. In the interior, a big wardrobe which covers the wall, orders the objects in each room and also contains the kitchen.

i. Present situation. It can be rented at: http://www.casasdodouro.com/casadebaiao