Sagy sits below 98% of compared French towns for one-person households (23%)
Set against 11% in the typical compared French town, 5.4% of households have no car in Sagy. Flats are rarer here than in 86% of compared French towns. The 2023 Census put the town’s population at 1,096, in 450 households. The share of households headed by a retired person stands at 38%.
Throughout this page, the Val-d'Oise median and the France median are the median of compared communes (those with an overall grade), each figure its own median. Source: INSEE, census 2023.
What stands out about the people of Sagy
Fewer residents than in 2012
Sagy had 1,162 residents at the 2012 census and 1,096 in 2023, down 6%: slower growth than in 90% of compared French towns. Population ↓
Written from INSEE’s census 2023 on this page, against compared French towns.
Slower growth than 90% of compared French towns: Sagy changed by −6% since 2012
Residents at INSEE’s last three censuses, each recast in the 2026 commune boundaries. France has no yearly estimate by commune between censuses.
2012 to 2023
2017 to 2023
Over those years, the median Val-d'Oise town changed +8% and the median compared French town +5%. Between 2012 and 2017 the population moved −4%, then −2% to 2023.
Half of Sagy is over 45.7, older than 61% of compared French towns
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ Sagy 45.7. The median compared French town: 44.
Higher than in 56% of compared French towns: 23% of residents are 65 or over. For Sagy, the census puts residents aged 15 to 24 at 10%.
Women and men · all residents
49% women, 51% men
About an even split. Median share of women: Val-d'Oise 51.5%, France 51.8%.
A lower share of single-parent households than 99% of compared French towns, at 3.3%
A household is everyone who shares a main home (résidence principale). Household types come from INSEE’s fuller sample of a quarter of census forms.
Against the Val-d'Oise median and the France median
Living alone · share
Households average 2.4 people. For comparison, 10% of households are single parents in the typical compared French town. More couples with children than in four fifths of compared French towns: 31%.
A lower share of empty homes than 64% of compared French towns, at 5.7%
Every home the census counted: main residences, second homes and occasional dwellings (INSEE counts them together), and empty homes. Owning and renting are on Cost of living.
All homes · share of homes
Type of home
Cars per household · share of households
Recent arrivals (under two years) make up 8.7% of households; long-stayers (30 years or more) 31%. Households in social housing are rarer here than in 99% of compared French towns. To put it in context, 6.7% of homes stand empty in the typical compared French town. Little separates the share of second homes here, 2.3%, from the figure in the typical compared French town.
A median standard of living of €33,650 a year
The standard of living (niveau de vie) is a household’s disposable income after taxes and benefits, divided by its consumption units (UC) to allow for its size and make-up: 1 for the first adult, 0.5 for each other person 14 or older, 0.3 for each child under 14.
Medians of compared communes. Source: INSEE, Filosofi 2023.
The median standard of living in Sagy is €33,650 a year per consumption unit: higher than in 94% of compared French towns.
In Sagy, 10% of households are headed by a manual worker, fewer than in 76% of compared French towns
Households by the socio-professional group (PCS) of their reference person, INSEE’s own categories. Jobs and commuting are on the Work & commute page.
Households by reference person’s group · share of households
In the typical compared French town, the share of households headed by a manager or professional is 9.4%; Sagy has 12%. As a yardstick, 14% of households are headed by a manual worker in the typical compared French town.
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
Sagy sits below 71% of compared French towns for immigrants (4.3%)
INSEE publishes two measures, which overlap but aren’t the same. Neither is the UK’s “born abroad”.
Share of residents · census 2023
Immigrant (immigré)
Born abroad, not French at birth. Someone stays an immigrant after becoming French. A French citizen born abroad (for example in Algeria before 1962) is not one.
Foreign national (étranger)
Not a French citizen today, wherever born. A child born in France to foreign parents can be a foreign national without being an immigrant.
The median compared commune in Val-d'Oise has 16%; immigrants here make up a share lower than in 71% of compared French towns. Foreign nationals make up about one in 37 here (2.7%). For comparison, 6.5% of residents are immigrants in the typical compared French town.
INSEE publishes no country of birth or ethnicity by commune in these tables, and the census doesn’t ask about religion.
Sagy sits above 92% of compared French towns for married residents (50%)
Residents 15 and over by how they live: the census asks both the legal status and whether people live as a couple.
Residents 15 and over · share
In the typical compared French town, a quarter of residents 15 and over are single; in Sagy, 21%. For married residents, the comparison in the typical compared French town is 43%.
In Sagy, 13% of adults out of school have no qualification, fewer than in 86% of compared French towns
Highest diploma of residents 15 and over who have left education, in French terms: the levels don’t map one-to-one to UK or U.S. ones.
Highest diploma · 15 and over, out of education
Compared with 30% in the typical compared French town, 41% of adults out of school hold a higher-education qualification here. Adults with no qualification: 19% in the typical compared French town, for comparison.
20th highest median age among 41 French towns of 1,096 to 2,582
The 40 compared French towns nearest in population, by median age. Hover for each one’s second homes and immigrants; click for its page.
At the ends of the range sit Villejust (37.2), the youngest, and Prayssac (62.3), the oldest.
Sagy is older than every town around it
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
| Town | Median age | 65+ | Second homes | Immigrants |
|---|---|---|---|---|
| Sagy | 45.7 | 23% | 2.3% | 4.3% |
| Menucourt 6,184 · 1.7 mi | 38.2 | 13% | 1% | 8.8% |
| Courdimanche 7,311 · 2 mi | 36 | 9.6% | 0.7% | 17% |
| Vaux-sur-Seine 5,202 · 2.9 mi | 40.3 | 16% | 3.2% | 14% |
| Vauréal 16,079 · 3.2 mi | 36.6 | 12% | 1% | 16% |
| Meulan-en-Yvelines 8,950 · 3.3 mi | 38.3 | 16% | 1% | 20% |
| Cergy 70,906 · 3.8 mi | 30.4 | 9.1% | 4.4% | 30% |
Health, work, housing and schools
What this data can and can’t tell you
- Census 2023. INSEE’s census is a rolling survey: a fifth of small communes each year, 8% of homes in large ones each year. “2023” pools the surveys of 2021 to 2025, so the figures describe the town around 2023, not on one day.
- Medians of compared communes. The comparisons are the median of the département’s compared communes and of France’s (those with an overall grade), each figure its own median: not the total for the département or for France, which large cities pull towards their own figures.
- Immigrants and foreign nationals. INSEE’s two measures: an immigrant was born abroad without French nationality; a foreign national isn’t French today. Neither is a count of people born abroad, which INSEE doesn’t publish by commune.
- Second homes. Homes used for holidays or weekends, with occasional dwellings (kept for work, for example), which INSEE counts together. Their owners are counted where they live, not here.
- Standard of living. INSEE’s Filosofi: disposable income per consumption unit, from tax and benefit files, 2023. The poverty rate is the share of residents below 60% of France’s median. Not published for the smallest communes.
- What France doesn’t ask. The French census asks nothing about ethnicity, religion, language or health, so this page has no such section.
Questions about who lives in Sagy
What is the population of Sagy?
1,096 at INSEE’s 2023 census, 6% fewer than in 2012 (1,162).
How old are Sagy’s residents?
The median age is 45.7, older than 61% of compared French towns. 21% are under 18 and 23% 65 or older.
How many second homes are there in Sagy?
11, with occasional dwellings: 2.3% of all homes, against 2.1% for the median compared French town.
How many immigrants live in Sagy?
INSEE counts 47 immigrants (born abroad, not French at birth), 4.3% of residents, and 30 foreign nationals (2.7%). The medians of compared French towns are 6.5% and 4.3%.
What is the median income in Sagy?
€33,650 a year per consumption unit in 2023 (median of compared French towns €25,970). Source: INSEE, Filosofi.
Sources: INSEE, census 2023 (population, ages, households, homes, marital status, diplomas, immigrants, foreign nationals, employment), 2026 geography · INSEE, Filosofi 2023 (standard of living, poverty) · IGN Admin Express (boundaries) · Medians and percentiles: TownRatings, over compared French towns, updated November 4, 2026. Under the Licence Ouverte / Open Licence 2.0 (Etalab).
Contains public sector information under the Licence Ouverte / Open Licence 2.0 (Etalab): INSEE, DGFiP, the Interior Ministry’s statistics service (SSMSI), the Ministry of Education (DEPP), the Health Ministry’s statistics service (DREES) and the Housing Ministry (Carte des loyers). Commune boundaries: IGN Admin Express.