A 'blinkered' approach to brownfield development is resulting in the loss of ecologically valuable sites warns ADAS, the UK's largest rural and environmental consultancy. William Little, an ADAS environmental planning expert said: "The government has set targets that more than half of all new homes should be built on brownfield sites. But this approach is too inflexible. In some cases, brownfield sites are of greater ecological value than some greenfield sites and should be left free of construction. "It is frequently the case that when land is left abandoned, rare plants and species that have disappeared from agricultural land can be re-established." ADAS is calling on planning authorities not to simply authorise brownfield construction as a matter of course. "Planning authorities are exhorted to build on previously used land but this inflexible approach threatens the destruction of important sites that act as a reservoir for rare and endangered species and provide open space for people in urban areas," said Little.