In addition to actual plans the use of land is regulated with areas requiring planning. Areas requiring planning are areas the use of which involves needs that require special measures, such as road, water main or sewer construction or arranging areas for free use. Provisions concerning areas requiring planning also apply to construction where the environmental impact is so substantial as to require more comprehensive consideration than the normal permit procedure. In local master plan or building ordinance the local authorities may also designate certain areas as areas requiring planning due to their location, community development requiring planning may be expected, or where land use planning is warranted by particular environmental values or hazards.
The law lays down special preconditions concerning building permits in areas requiring planning. Local authorities decide upon the existence of such preconditions during construction permit procedures or other procedures. Whether or not a certain area belongs to an area requiring planning becomes clear in the building permit procedure at latest.