The available space should be used efficiently and excessive programming avoided. The authorities concerned assess whether the intended development meets a regional, inter-local demand for industrial sites, offices, residential buildings, retail developments or other urban amenities that has not been met elsewhere. Besides a quantitative assessment (number of hectares or number of homes), there must also be qualitative demand (e.g. an industrial site where a heavier environmental burden is permitted or a specific type of living environment) at a regional scale.