Concrete is a material that gives architects and engineers great control over its form and appearance, especially where its visual qualities have been fully considered at the design stage. The appearance of concrete can be radically altered simply by intelligent selection of materials, but pigments and surface treatments extend the palette further, and understanding of the interactions between concrete surfaces and the environment can minimise surface deterioration. Concrete can be delivered to its point of use in a fluid state so there are few limitations on the forms which can be created, and developments in fabrication techniques and formwork mean that concrete's versatility of form is steadily expanding. This volume explores all these subject areas and the issues raised under two themes: The urban environment, and Radical design and form. Each theme includes a Keynote paper by the foremost exponent in their respective fields. This volume forms Volume 4 of the six-volume set of proceedings of the International Congress 'Concrete: construction's sustainable option', organised by the Concrete Technology Unit of the University of Dundee in July 2008, and available as a set.