A significant number of building materials are based on wood. Wood competes with other materials and products for many building applications from structural framing to cladding. Wood appears to be preferable because of its aesthetic and structural properties, its versatility, economic cost and environmental benefits. However, timber wastage within the construction industry is incalculable. Waste occurs at all stages of the timber resource stream: procurement, conversion, installation, use, maintenance, dismantling and eventual disposal. Much of this loss can be avoided through eco-design strategies based on a better understanding of the total resource flows. This thesis addresses the ecological implications associated with the use and over-exploitation of timber in building construction. Applying bio-sensitive design principles and using a life cycle approach, the thesis examines ways of maximising timber resource yield through appropriate materials selection, design strategies and construction techniques to reduce their ecological footprint. Finally, an easy-to-use guide that incorporates economic and aesthetic-value criteria to the analysis is developed. The guide is aimed to offer a flexible decision-support tool that enables designers and other people involved in the construction industry to comprehend in a systematic way, the multiple dimensions interacting when selecting timber-building products. It is thus, intended to explore in practice the implications and trade-offs of state of the art timber products with the ultimate aim of integrating the ecological dimension to the decision-making process.