EULOGY TO MODERNITY IN WOOD AND STRAW
Located on the edge of the Forêt de Fontainebleau, the “Maison Trilogis” is more than just a single-family home complex: It can be described as an architectural manifesto, combining innovation, sustainability and harmony with the unique forest landscape.
Emerging as the winning project from an international competition, this building complex of two prefabricated houses in timber-straw construction combines constructive innovation with the demanding passive house standard.
The linear volume of the main building, which floats on steel piles and has floor-to-ceiling glazing, is integrated into the coordinate system formed by the verticals of the trees and the horizontal of the plot and is oriented to the south, optimizing heat generation through solar radiation. This motif, reminiscent of Mies van der Rohe's Farnsworth House, an architectural icon of American modernism, is reinterpreted here and adapted to today's sustainability requirements. The equally rational and functional floor plan combines the programmatic requirements and the Franco-American clients' desire for a single-storey construction with communication with the surrounding nature based on covered terraces and well-placed visual connections.
At some distance from the main building stands the guest house, a cubic volume with black timber cladding, which was built on top of an existing basement, part of an earlier, unfinished project. The existing basement disappears under an artificial mound and can only be guessed at by the clearly defined cut-outs for the access staircase and ramp.
In contrast to the modernist architecture cited above, sustainability considerations were a key design criterion here: the pile foundation of the main building and the placement of the guest house on the existing basement allow for minimal intervention in the natural environment, with earthworks limited to the underground parking spaces and technical rooms. Only a few trees had to be felled, and one tree integrated into the main terrace even appears to “grow through” the building.
The prefabricated timber construction, the choice of straw and wood wool as insulation materials and the minimal energy consumption of the passive house standard reduce the ecological footprint to a minimum. With its cladding made of pre-patinated zinc sheeting, its timber cladding charred in a controlled manner using the Japanese Yakisugi method to improve durability, and its green roofs, the building complex blends discreetly and elegantly into the dreamy forest landscape.
CONTEXT
Location
The “Maison Trilogis” is located on the edge of the Forêt de Fontainebleau on an 8,310 m² plot and benefits from an exceptional but challenging environment. The Forêt de Fontainebleau is one of the historic and protected forests with the greatest biodiversity in Europe, which means that the planners are required to take particular care in their treatment of the existing. The architects have taken this into account by carefully integrating the structures, by the shape of the building, but also by reducing the earthworks and foundations to a minimum.
Organization and orientation
In addition to functional and aesthetic aspects, sustainability considerations were the decisive criterion for the design and orientation of the two houses. For example, the volumes were oriented to the south to make use of solar energy and fitted with shade-providing canopies to prevent overheating in summer. The pergola-covered terraces on both sides create the desired linearity of the main houses floating structure and also enable the relative compactness of the insulated volume required to achieve the passive house standard.
In addition to the mechanical ventilation system with heat recovery, well-dimensioned window openings on the opposite façades of the houses ensure sufficient cross-ventilation in summer.
PROGRAM
Main house and guest house
The main house (153m2) is divided into two areas: The living area with open kitchen, dining and living room as well as the entrance area separated by a fireplace on the one hand, and the sleeping area with bedrooms and bathrooms on the other. A spacious terrace extends the living area into the outside space, while a second terrace provides access to the outside from the master bathroom. The two terraces are connected by an external corridor in front of the south-facing façade.
The guest house (40m2) is a small independent building with a mini-kitchen, bathroom, sleeping gallery and living room and can accommodate up to four people.
CONSTRUCTION
The technical and architectural measures aim to minimize the impact on the nature of the site and reduce the ecological footprint:
- Spot foundations made of metal piles
- Prefabricated timber construction with straw and wood wool insulation
- Wood and zinc cladding
- Green flat roof
- Certified passive house windows with triple glazing
THERMAL AND SUSTAINABLE CERTIFICATIONS
The project meets the passive house standard and is to be certified. It also meets the criteria of the French “Energie-Carbone E3C2” certificate, thanks to a reduced CO2 footprint and planned energy generation by photovoltaic systems.
The passive house standard is a certification developed in Germany and has now become an international standard, with the aim of greatly reducing heating and overall energy consumption while maintaining a high level of living comfort. In addition to a compact design aimed at maximizing solar heat gains, the special features include:
- Strong building insulation
- High airtightness of the outer skin
- Passive house-compatible windows with triple glazing
- Mechanical ventilation system with highly efficient heat recovery
- Reduction of thermal bridges (thermal weak points in the outer skin)
A passive house must not exceed a heating energy requirement of 15kWh/m2/a and a total primary energy requirement of 120 kW/m2/a. Summer overheating must not exceed 25°C by more than 10% per year. The airtightness must be at least 0.6 V/h at a pressure of 50 hp.
