Planning zones A, B, C, D, E and F in Italy: what they mean

On a municipal certificate, in a listing or on the town plan map you will often see a letter: zone B, zone E, zone C2. These are the homogeneous zones (zone territoriali omogenee), and they come from a decree of 2 April 1968, number 1444, which implemented the so-called "bridge law" of 1967 (law 765, article 17).

The decree does two things. It defines the six zones (article 2), and for each one it sets limits that plans cannot exceed: how much can be built, how high, how far apart, and how many square metres of schools, green space and parking are needed per resident. Everything else is up to the municipality. So the letter tells you the type of zone, while the precise rules for your plot (building index, heights, permitted uses) are in the implementation rules of that municipality's plan, and they can be much stricter than the decree. Many plans also split each letter into sub-zones, B1, B2, C1, with different rules.

Zone A: the historic centre

Under the decree these are the parts of town of historic, artistic or special environmental value, together with the surrounding areas that belong to them. Here the plan aims to preserve: maintenance, restoration and conservative renovation are usually allowed, while demolishing and rebuilding or adding a storey is rare and follows specific rules, building by building.

Where the plan does allow new buildings, the density cannot exceed half the zone's average and never more than 5 cubic metres per square metre (article 7). Heights cannot exceed those of the surrounding historic buildings (article 8), and distances cannot drop below the existing ones (article 9). For a buyer, zone A means slower and more closely checked works, even for a window or a coat of render.

Zone B: the built-up town

These are the areas built up wholly or partly, outside historic centres. The decree gives a precise threshold: an area is partly built up when buildings cover at least one eighth of the land (12.5%) and the density exceeds 1.5 cubic metres per square metre. It is the zone of post-war residential districts, where the plan completes what is there: buildings are renovated, demolished and rebuilt, and the remaining empty plots are filled in.

If the plan allows a single building to be demolished and rebuilt, the density cannot exceed 7 cubic metres per square metre in municipalities of more than 200,000 inhabitants, 6 between 50,000 and 200,000, and 5 below 50,000, or else 70% of what was there before (article 7). New buildings cannot be taller than those around them, unless a detailed plan provides for it (article 8).

Zone C: new neighbourhoods

These are the areas set aside for new development, empty or built up below the zone B thresholds. This is where housing developments are laid out: a detailed plan is often needed before a building permit, with roads, parking and green space that the developer builds or hands over to the municipality.

In zone C the decree requires the full 18 square metres of public space per resident (4.5 for schools, 2 for community facilities, 9 for parks and sport, 2.5 for parking), reduced to 12 in municipalities that the plan expects to stay at or below 10,000 inhabitants (articles 3 and 4). Between facing walls with windows, the distance must be at least the height of the taller building (article 9).

Zone D: industry and workshops

These are the areas set aside for new industrial or similar sites: industrial units, workshops, warehouses, and sometimes shops and offices, depending on the plan. Whether a house is allowed, and on what terms, is up to the plan's rules. The decree requires at least 10% of a new industrial site to go to public space, green space or parking, roads excluded (article 5).

Zone E: farmland

These are the areas set aside for farming. It is the zone that most surprises people buying a field: for homes the decree allows at most 0.03 cubic metres per square metre (article 7), which is 300 cubic metres on one hectare. Using the decree's own ratio (80 cubic metres for every 25 square metres), that is just over 90 square metres of gross floor area. Regional laws and plans usually add further conditions, and often reserve building for professional farmers. Barns, haylofts and stores for farming follow separate rules, again set in the plan.

The decree excludes from zone E the areas that remain agricultural but where the division of ownership calls for development to be treated as zone C: countryside already dotted with scattered houses. How to check whether a piece of land is really agricultural or building land: Agricultural or building land: how to check.

Zone F: facilities of general interest

These are the areas set aside for facilities and installations of general interest: secondary schools, hospitals, large parks, utility plants. Where they are needed, the decree requires at least 1.5 square metres per resident for secondary education, 1 for health facilities and 15 for urban and regional public parks (article 4). A private plot in zone F, or in an area for public facilities not yet built, is usually meant to become public: before buying it, ask the municipality whether it is earmarked for compulsory purchase.

Distances apply everywhere

Outside zone A, for every new building the decree requires at least 10 metres between a wall with windows and the wall of the building opposite (article 9). Where a road open to traffic runs between them, the distance rises to the width of the road plus 5 metres on each side if the road is less than 7 metres wide, 7.5 metres on each side between 7 and 15 metres, and 10 metres on each side above 15. It is the rule that most often stops an extension or an extra storey. Regions can provide exceptions by their own law (DPR 380/2001, article 2-bis).

A knock-on effect for landscape protection

The letters matter outside the plan too. Italy's landscape code protects coasts, lake and river banks and woodland by law, but excludes the areas that the plan classed as zone A or B on 6 September 1985 (D.Lgs. 42/2004, article 142, paragraph 2). Two houses at the same distance from the sea can therefore face different requirements depending on how the plan of the time classed them.

How to find out which zone a plot is in

The definitive answer is in the planning use certificate (certificato di destinazione urbanistica), which you request from the municipality with the sheet and parcel numbers. Before that you can look at the plan map on the municipality's website. Not every plan still uses the letters: in Lombardy the PGT talks about the consolidated urban fabric, transformation areas and agricultural areas, and in Turin each plan has its own codes.

In Lombardy, Veneto, the Province of Bolzano and the Metropolitan City of Turin, the report says what the municipal plan provides for the parcel; in Veneto with the zone from A to F, for the share of the parcel in each (Municipal plans). What can be built, from the plan to the restrictions: What can be built on a plot in Italy.

Sources

• DM 2 aprile 1968, n. 1444, text published by the Chamber of Deputies (Gazzetta Ufficiale no. 97 of 16 April 1968): articles 2 (zones), 3-5 (public space), 7 (density), 8 (heights), 9 (distances).
• DPR 380/2001, article 2-bis (regional exceptions) and article 30 (planning use certificate).
• D.Lgs. 42/2004, article 142 (areas protected by law).