What is the energy efficiency of residential buildings in Italy? The answer changes radically depending on the region. Processing data Resolglass (April 2026) based on SIAPE/ENEA and proprietary data show a significant gap between territories: ranging from more virtuous areas such as Trentino-Alto Adige, where the share of buildings in energy class G is limited to 19.8%, up to Calabria, which reaches 37.6%. The difference between regions does not only concern environmental sustainability, but also the economic value of properties.
A high presence of class G buildings translates into higher energy costs, less attractiveness of the real estate assets and a real risk of progressive devaluation of the assets. On the contrary, regions with a greater diffusion of classes A and B are more competitive, more resilient and better prepared to face the new European regulatory context.
The national data says that around 30% of Italian properties are still in class G, but it is enough to go into regional detail to see how much the situation changes. The North clearly leads the way, with Trentino-Alto Adige ranking as the most efficient region with 19.8% of buildings in class G and 20.3% in class A. They are followed by:
- Valle d’Aosta (21.8% in G, 18.2% in A).
- Lombardy (24.8% in G, 15.4% in A).
- Veneto (25.7% in G).
- Friuli-Venezia Giulia (25.8% in G).
- Emilia-Romagna (26.3%).
All these regions, therefore, all below the national average for the share of less efficient properties. In Central Italy the values approach or slightly exceed the average. More specifically, we have:
- Tuscany at 29.1% of class G buildings.
- Marche at 30.1% of class G buildings.
- Umbria has 31.2% of class G buildings.
- Lazio at 31.3% of class G buildings.
- Abruzzo at 31.5% of class G buildings.
The picture changes drastically in the South and in the Islands, where the delay is more marked:
- Puglia at 35.4% for class G buildings.
- Sardinia at 35.6%.
- Molise at 36.3%.
- Basilicata at 36.4%.
- Sicily at 36.6%.
- Campania at 36.9%.
At the bottom of the ranking is Calabria, with 37.6% of buildings in class G and just 7.5% in class A. A gap of almost 18 percentage points compared to Trentino-Alto Adige which highlights an energy-fragmented Italy.
