🏙 Property in Les Alluets-le-Roi (78580)

Les Alluets-le-Roi has a population of 1,390, a density of about 186 inhabitants per km². Advertised rents for flats are around €16.9/m² per month (2025). Between 2022 and 2025, advertised rents are down by 1.0%. The overall property tax rate on buildings (taxe foncière) is 31.29% in 2025, up by 4.98 points compared with 2021. The average reference taxable income per household is €59,460 (2024), and 70% of households pay income tax. Les Alluets-le-Roi has had 3 natural disaster declarations since 1982, 2 of them for floods or mudslides. The national register lists 1 registered co-ownerships (2 units).

📰 Les Alluets-le-Roi at a glance

Département: Yvelines (78) · Region: Île-de-France

Size and profile

Les Alluets-le-Roi has a population of 1,390: it is a medium-sized municipality for its département (median: 1,302 inhabitants). Population density there is 186 inhabitants per km²: a small-town or fringe profile.

Rents and prices

At €16.9/m² per month, advertised rents exceed the département median (€16.1/m²). Between 2022 and 2025, the advertised rent has fallen by 1.0%, more slowly than the median of the municipalities in its département (11.2%).

Incomes and taxation

The average reference taxable income per household (€59,460 in 2024) is above the département median (€48,984). It has risen by 3.3% since 2018, more slowly than the median of the municipalities in its département (16.5%). 70% of tax households there pay income tax, against 67% for the département median. The overall property tax rate (31.29%) is 2.8 points higher than the median of the municipalities in its département (28.54%).

Hazards and energy

Les Alluets-le-Roi has had 3 natural disaster declarations since 1982, i.e. far fewer than the département median (6). They mainly concern floods and mudslides (2 declarations).

Summary written automatically from the figures on this page, comparing the municipality with the median of the municipalities in its département (or of France when the département has too few municipalities with data).

💶 Prices and rents: how they have changed

5 listings observed. Estimate calculated across a group of neighbouring municipalities, less precise than a municipal estimate. These are advertised rents, service charges included: they are higher than the rents of existing leases. The estimation method was revised in 2022: only the 2022 and later editions, which are comparable with each other, are shown.

👥 Household incomes

Tax statistics from the DGFiP: income for 2024, declared the following year. The reference taxable income is an average: very sensitive to high incomes, it is not a substitute for a median income. The incomes are those of the tax households living in the municipality, not only those of co-owners.

🌊 Natural hazards

A declaration recognises a state of natural disaster for a given event; it triggers the “natural disasters” cover of home insurance policies and of the building’s insurance. “Drought” declarations relate to the shrinking and swelling of clay soils, a frequent cause of cracks in buildings. A risk statement (état des risques) must in particular be attached to a sale or lease when the property lies in an area covered by a prevention plan, in seismic zone 2 to 5, or with a class 3 radon potential. This page presents municipal data: it does not replace the risk statement drawn up for the property’s address.

🧾 Property tax and local taxation

The overall rate adds the municipal share and the inter-municipal share. The tax due by an owner equals this rate applied to half of the home’s cadastral rental value, reduced where applicable by exemptions.

🏢 The co-ownerships of Les Alluets-le-Roi

Budget and arrears are declared by the managing agents to the register; outliers are discarded and the median is used. They are only available for the years in which the register publishes them.

📊 Les Alluets-le-Roi compared with neighbouring municipalities

• Advertised rent: 16.9 €/m²/month, rank 3 of 9 municipalities compared, from highest to lowest (neighbours’ median: 16.9 €/m²/month).
• Average reference taxable income: 59,460 €, rank 7 of 9 municipalities compared, from highest to lowest (neighbours’ median: 65,075 €).
• Property tax rate: 31.29 %, rank 6 of 9 municipalities compared, from highest to lowest (neighbours’ median: 32.79 %).

The 8 nearest municipalities (as the crow flies, from the centre). Latest values available; “—”: data not published or too few sales. Rents are estimated for groups of municipalities: neighbours may share the same estimate. The rank compares the municipality with these neighbours, not with the whole of France.

📚 Sources and method

Each indicator comes from an open dataset that is kept over time: when a source is updated or corrected, the old value stays on record, which makes it possible to follow changes from one year to the next.

• Ministère de la Transition écologique, base GASPAR (Géorisques) — Licence Ouverte 2.0. Retrieved in October 2026.
• Carte des loyers © Ministère de la Transition écologique / ANIL — Licence Ouverte 2.0. Retrieved in October 2026.
• INSEE, API Géo (Etalab) — Licence Ouverte 2.0. Retrieved in October 2026.
• ASN / IRSN, potentiel radon des communes — Licence Ouverte 2.0. Retrieved in October 2026.
• DGFiP, impôt sur le revenu par collectivité territoriale (IRCOM) — Licence Ouverte 2.0. Retrieved in October 2026.
• Registre national d'immatriculation des copropriétés (ANAH) — Licence Ouverte 2.0. Retrieved in October 2026.
• DGFiP, fiscalité locale des particuliers — Licence Ouverte 2.0. Retrieved in October 2026.
• Sale prices: single-property sales (flats) in the streets where the register lists co-ownerships; median calculated from 10 sales or more.