The Commission on Human Settlements, in its decision 13/24 of 7 May 1991, decided to include in the agenda of its fourteenth session in 1993 the theme named "Appropriate, intermediate, cost-effective building materials, technologies and transfer mechanisms for housing delivery". The first section of this report presents the current scenario and recent trends in production, imports and prices of building materials in developing countries. That gives an indication of the size and scope of the problem. The second section analyses the factors contributing to the poor growth in production and the continuing high prices of building materials. The third section looks to the future, identifying challenges which will have to be faced in formulating an effective strategy for increasing the supply of building materials in a sustainable manner. The third section also identifies some new opportunities which can assist the process. The report then outlines an operational strategy for the development of the building materials sector.