The average size of Italian Nuts2 units (19 regions and the two autonomous provinces of Trento and Bolzano), in terms of surface area, is of just over 14,000 km2; each unit has 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 9 inhabitants per km2 over the last 10 years and confirmed at 201 inhabitants per km2 .
In 2016, 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 (5,825 km2). The total number of sites grew from 2,589 in 2015 to 2,596 in 2016, with an average extension (terrestrial and marine) of approximately 24.7 km2 per site. While the number of Spa remained unchanged over 2015, Sci and Sca increased from 2,314 to 2,321, with a slight increase in the sea surface area.
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 2005. 2014 marked the ninth consecutive decline and the figures for the first half of 2015 do not seem to indicate a reversal of the trend.