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Castelletto d'Erro: what to know before buying a home

A municipality in the province of Alessandria, Piemonte. Official data on earthquakes, population, services and transport.

Liveability index free for any address

Search for an address in Castelletto d'Erro

The report looks at the exact point: landslide and flood risk, seismic zone, price per square metre for the area, services and nearby stops.

For example: Via Roma 1, Castelletto d'Erro.

Castelletto d'Erro, the tower above the Erro valley

A medieval tower on the hilltop is the landmark of Castelletto d'Erro, a small municipality in the Acqui Terme area overlooking the valley of the river Erro. The village stands above five hundred metres among woods, meadows and scattered houses, and Acqui Terme is the reference town for services, schools and work. The climate is zone E, with cold winters.

Homes are mostly stone houses and farmhouses, often with land around them. Buyers should budget for work on the roof, walls and systems, and for isolated houses check water supply, drainage and winter access. The road up from the valley floor is narrow and steep, so drive it calmly before deciding, ideally at the times and in the months you would actually be using it.

The population is small and elderly: Istat, the national statistics office, counted 128 residents in 2023, 14.7% fewer than the 150 of 2011. Over-65s make up 42.2% and the average age is 58.1, against 48.9 in the province of Alessandria. Foreign residents account for 10.9%. Declared incomes are below the provincial average.

Castelletto d'Erro is in seismic zone 3 of the national classification, like 127 of the 187 municipalities in the province, with an expected ground acceleration of about 0.051 g, a low value. For older stone houses, the quality of maintenance over the years matters most.

The Revenue Agency (Agenzia delle Entrate) publishes cadastral maps, which help establish which land is included in a sale. On the slopes the report checks the gradient and the official landslide maps for the exact address.

Key points

  • Acqui Terme area municipality above the Erro valley, with a medieval tower.
  • 128 residents in 2023, over-65s at 42.2%.
  • Foreign residents at 10.9%, average age 58.1.
  • Seismic zone 3, expected acceleration about 0.051 g.

Overview

Castelletto d'Erro is a municipality in the province of Alessandria, in Piemonte. At the end of 2023 it had 128 residents, among the smallest in the province (180 of 187).

Earthquakes

For Italy's Civil Protection Department, Castelletto d'Erro is in seismic zone 3, a zone where strong earthquakes are possible but rare. Most municipalities in the province (127 of 187) are in the same zone.

In the built-up area, the expected ground shaking (peak ground acceleration, PGA) is about 0.051 g, a moderate value: the level with a 10% probability of being exceeded in 50 years, on rock.

Even in zone 3, seismic standards apply to new buildings: for an older building, ask about the design year and any structural work.

Population

Compared with the 2011 census, the resident population has fallen by 14.7%. The estimated average age is 58 years, higher than the province average (49). 42% of residents are over 65 (the regional figure is 27%). Foreign residents make up 10.9% of the population. On average, a household has 1.8 members.

Income and climate

In tax year 2024, taxpayers in Castelletto d'Erro declared an average taxable income of 19,928 euros, below the provincial average (25,143 euros). The Italian average is 24,895 euros.

Castelletto d'Erro is in climate zone E, with 2,939 heating degree days: heating may be switched on from 15 October to 15 April, for up to 14 hours a day. The same table puts the town hall at 544 metres above sea level.

Public transport

We do not yet have open public transport timetables for this municipality: the report says so explicitly, without inventing distances.

How built-up it is

Buildings, roads, car parks and other sealed surfaces cover 5.3% of the land in Castelletto d'Erro, compared with 7.2% in the province and 6.7% in the region. In 2024 built-up land stayed almost the same.

Radon and contaminated sites

Castelletto d'Erro is not among the radon priority areas designated by the Regione Piemonte in 2023. According to the ISPRA map, the estimated radon emission in the municipality is low. Radon varies from building to building and can only be known by measuring it, especially on ground floors and in basements.

Official databases list no contaminated sites in Castelletto d'Erro.

Landslides and flooding

Landslide and flood hazard changes from one street to the next even within Castelletto d'Erro: the report checks the address against the ISPRA maps.

House prices

The Revenue Agency's price ranges per square metre (OMI) apply to zones, not to whole municipalities: the report gives the range for the address's zone.

Land registry

The cadastral maps for Castelletto d'Erro are public: from the address the report finds the sheet and parcel number.

Liveability area by area

The Vicinalia liveability index runs from 0 to 100 and looks at the place, not the people who live there: services within walking distance, transport, green space, natural hazards, air, quiet, buildings and connection. Here it is worked out at the centre of each of the 6 inhabited census areas in Castelletto d'Erro. Half of the residents live in areas scoring 57 or more.

Residents by band

  • fair 100.0%

Vicinalia index by census area, licence CC BY-SA 4.0. Data: IdroGEO ISPRA (2026), Istat, INGV, EEA, AGCOM, Overture Maps and OpenStreetMap.

The colour is the value at the centre of the area. For an exact address, search for it above: the free check looks at that exact point. How the index is worked out

Data sources

ISTAT code 006048. The text on this page is generated automatically from the data.