from The Whole House Book by Pat Borer and Cindy Harris
The goal of present design is to translate this ideal into reality.
The durability of this house is demonstrated by its ability to withstand time, weather and temperature. The design is innovative for its unique wall construction. ECOPANNEAUX (compressed straw panels) - straw bale - lime plaster) wall sandwich was achieved as a result of several years of research into straw bale building. It minimizes to the maximum extent the possible dangers encountered by using straw bale technology: moisture in the straw, rodents in the cavities and danger of fire spreading in the chimney gaps around the studs. To avoid all of that: At first the interior cladding in ECOPANNEAUX is mounted to the timber construction. Internal faces of the straw bales are pre-dipped in clay slip, tightly fitted between timber studs and then pressed against the ECOPANNEAUX. Each straw bale is further compressed from the top with a timber lath (picture 1). Every unevenness in the wall surface and every cavity between bales is tightly filled with a loose straw. The exterior of the straw bale wall is lime plastered (with mixture of lime putty and sand) in three layers. This way there is no space for rodents, no chance for fire to catch or spread. ECOPANNEAUX with a valid certification act as a great fire and moisture protection. Because of their low vapor resistance the panels don't enclose the straw bale insulated timber frame wall completely, rather the whole wall is able to breathe and any moisture that can possibly affect the straw has a chance to escape via much more "vapour open" lime plaster to the exterior of the building. There are many other factors that contribute to the durability of this house. Among them are; grass on the roof that extends the life of its waterproofed layer and the fact that the house is elevated from the ground. Good ventilation of the underspace will ensure that the moisture or radon gas (if present) is dissipated.
The design is flexible. The house could be built on any site with an entrance access from the north and minimal breadth of 20m (picture 2). The construction allows for two large empty rooms on each floor facing south with a service (utility) space at the north side. Special consideration was given to permit the possibility of building the house in phases (picture 3) and offering the opportunity for future expansion to the east or mainly to the west.
To meet the needs of particular inhabitants, the house must be attractive and comfortable and require little in terms of maintenance. The dimensions of the house resemble human scale and by obeying the golden mean they align themselves in harmonious proportion that is pleasing. The rooms are modest and at the same time they feel spacious. The materials have natural colors and textures. The windows offer views and invite the breeze inside. The greenery in front of them filters the sun and creates flickering shadows. To soften the feel of the always straight paneling and to improve the interior climate there are sculpture-like structures built in adobe spread throughout the house (picture 4). There is "Nubian ladder" in the conservatory and a "Spine wall" around the stairs specially designed to improve the natural light distribution throughout the hall. The interior temperature is optionally maintained by a unique Computer Controled Natural Ventilation System (CCNVS) which was created exclusively for this particular house (picture 5). It uses mainly the cool of the earth and the heat of the sun to maintain a constant temperature in the interior of the home. Only extreme winter temperatures require the use of a traditional Scandinavian wood burning Mass Oven which uses fuel in the least polluting, most efficient way possible. The Mass Oven is situated in the center of the home where the air flow distributes its heat to every room. To complete the comfort and aesthetics, the house is surrounded by gardens and terraces which can be tailored to individual needs, in addition to outdoor space which may include a garage.
The greatest care was taken to simplify construction so that it would attract self builders, encouraging them to use recycled and renewable materials as much as possible. Because of the square modular grid that shows the position of the timber studs in the walls there are only one size straw bales, two sizes of doors and three sizes of windows required for the whole house. The highest benefit is achieved by creating a community of these self built homes so that resources can be pooled and relationships created and maintained through cooperation, mutual advantage and common interests.
The super insulated structure that envelops the house guarantees energy conservation and consists of straw, small profiles of timber and lime plaster. By using local straw bales and wood the embodied energy is as low as possible. Heat loss through the windows is minimized by their orientation. Seventy-seven percent of all glass surfaces, with high efficiency glazing, face south and are buffered by a double story conservatory which further insulates them from the elements.
What contributes to the heart of this design is its kindness to the earth, its friendliness to the builder, its potential for a maximum of living in a minimum of space and its ability to give so much to its inhabitants and require so little from them.