Precast concrete has many desirable properties which may contribute to sustainability. These are briefly discussed in relation to a number of construction projects. Concrete is able to store and release heat, and this can be used to reduce temperature fluctuations in buildings by circulating the air through precast hollow units. This reduces both carbon dioxide emissions and the energy requirements for air-conditioning. Concretes containing titanium dioxide additives are self-cleaning and also reduce pollution by reducing the generation of nitrogen oxides. Light-coloured concretes reflect heat and light, so reducing urban temperatures and lighting requirements. Permeable precast paving with collector systems and tanks has been developed to provide controlled urban drainage. Other developments include reusable components, reduced aggregate consumption, electronic tagging of components and the use of self-compacting concrete.