Insulation materials are the key tool in designing and constructing a energy thrifty buildings. This is demonstrated by the increasing thicknesses used in buildings, which also reflects in the growing sales of the branch. The European market of insulation materials is characterised by the domination of two groups of products inorganic fibrous materials and organic foamy materials. They all feature similar performance in terms of insulating capabilities, but otherwise present significant differences. These are discussed in detail in the following paper. Despite the fact that the thermal properties of the materials has not improved significantly of the last decade, a series of other features, like reaction to fire and moisture or mechanical properties have improved, sometimes even at the cost of insulation abilities. Furthermore, environmental and public health aspects play an increasing role, both in the search for 'optimum' materials for given applications, and in the aims set by the industry for future developments. These aims, examined within the legislative and market framework, are discussed in this paper, both as criteria for evaluating state of the art materials and as goals for future research developments. (C) 2004 Elsevier B.V. All rights reserved.