Compressed earth block technology, which is anchored in an initial concern to provide a new, economically and socially relevant response to housing production for the very poor, has continued to focus on this concern as its area of application has developed. Tens of thousands of family or communal homes and educational and health facilities have indeed been built since the early 1950s, when this building material emerged in its present form, at the CINVA Centre in Bogota, Colombia. These buildings have gradually confirmed the appropriation of this building technology. This simple building material, directly descended from the most ancient building traditions of the unbaked earth brick and from the fired brick, is capable of the same building and architectural subtlety and the same capacity for adaptation to the broad spectrum of factors - physical, ecological, social, economic and technical -which dictate the production of the built environment. As a building material, it has come to the fore by demonstrating its usefulness, which can be measured in technical and economic, but also in human terms. From a technical point of view, compressed earth block technology is firmly propped up by a scientific body of knowledge which is the equal of knowledge developed for other kindred building materials used in masonry. From an economic point of view, the compressed earth block, which has the advantage of being able to be locally produced and directly used, is today comparable and sometimes more competitive, depending on the context in which it is applied. As far as production and construction distribution chains are concerned, the technology generates employment across a wide range of jobs, from quarrying to brick-manufacturing, from builder to entrepreneur. In architectural terms, the compressed earth block ensures high quality results and at the same time, given optimum conditions of use, enables the foreign currency and energy savings which are essential to its relevance from a development point of view. At a human level, this technology provides concrete responses to the basic issue of improving the built environment and therefore the well-being of societies. Better quality construction and architecture, accessibility and replicability are the main criteria for evaluating this relevance from a human and economic view-point. But this relevance is possible only if the scientific and technical body of knowledge has been mastered, as well as the practical skills. This book supplies the intellectual and practical tools required for a correct application of compressed earth block technology in the field.
This book is also the fruit of patient and methodical team work, with the underlying objective of achieving the scientific, technical, social and cultural ratification of a new technology, the useful potential of which was obvious from the very first. Our intuition of this usefulness still, however, had to be confirmed. But today, we are talking about a technology which has not only achieved a level of industrial potential with production methods suited to the formal production sector, but also been able to remain on the scale of craft production and safeguard a degree of usefulness which is relevant to informal sector applications. This dual advantage can serve a wide range of architectural applications in the field of both housing and public facilities. The success of contemporary cases, notably the example of applications on the island of Mayotte (Comoro), confirms this dual advantage placed at the service of development ensuring economic and social spin-offs for the local population. This ratification needed to be confirmed by building up a body of knowledge and skill capable of being transmitted and appropriated, starting from high quality architectural examples. This is in fact what has in many instances occured, as is shown in the monographs which form the second part of this book, a book intended as much for land-use decision-makers as for architects, engineers or entrepreneurs; a book designed to boost confidence and supply the practical tools which seem to us, at the term of our research and field experience, indispensable; a book designed to disseminate this knowledge and skill towards a wider area of application, but most particularly towards housing and public facilities for local communities who have no choice but to use earth as a basic building material and who have a legitimate desire to benefit from modern technology. Such is compressed earth block technology, at the crossroads between traditional earth building customs and modern masonry building practices, a technology which offers an alternative whilst remaining within a range of high quality architectural applications.
Hubert Guillaud, Hugo Houben, CRATerre-EAG researchers.