The average size of Italian Nuts 2 units (19 regions and the two autonomous provinces of Trento and Bolzano), in terms of surface area, is of just over 14,000 km2; in 2014, each unit had an average population of over 2.8 million.
Population density, which is a useful indicator of the impact of human activity on the environment, continued to grow with an increase of nearly 10 inhabitants per km2 over the last 10 years.
In 2015, terrestrial protected areas included in the "Natura 2000" network covered 19.3 percent of the national territory, corresponding to an area of about 58,000 km2; protected sea areas represented 3.8 percent of total territorial waters area (5,811 km2). The total number of sites was equal to 2,589, with an average extension (terrestrial and marine) of approximately 24.7 km2 per site. While the number of protected sites remained unchanged over 2014, the total extent of marine areas increased, particularly in Lazio.
Data on the number of building permits, new dwellings planned and their relevant useful floor area are useful leading indicators of construction activities. The ratio of the above indicators to the number of resident households, measures the intensity of the phenomenon and shows a gradual contraction since 2006. Early figures for 2014 confirm that the reduction was less dramatic than in the previous two years, although it represented the ninth consecutive decline: the number of new buildings authorised was less than one sixth that of 2005.