A larger share of couples with children than 98% of compared French towns: 39%
Set against 11% in the typical compared French town, 0.8% of households have no car in Boullay-les-Troux. At the 2023 Census, 624 people lived locally, in 240 households. Put another way, about one in three: 31% of households are headed by a manager or professional. Flats are rarer here than in 99% of compared French towns.
Throughout this page, the Essonne 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 Boullay-les-Troux
A town of families
39% of households are couples with children and 6.1% single parents with children; 19% of residents are under 15. Households ↓
Many graduates
64% of residents 15 and over who have left education hold a diploma above the bac, 33% a master’s or more (bac+5). Qualifications ↓
Written from INSEE’s census 2023 on this page, against compared French towns.
Slower growth than 75% of compared French towns: Boullay-les-Troux changed by −1% 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
From 2012 to 2017 the population moved +2%, and from 2017 to 2023 −3%; the median compared French town changed +5% and the median Essonne town +6%.
Only 8% of residents are 15 to 24 in Boullay-les-Troux
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ Boullay-les-Troux 46.9. The median compared French town: 44.
The figure for residents aged 65 and over is 20% in Boullay-les-Troux and 22% in the typical compared French town. Set beside that, 11% of residents are 15 to 24 in the typical compared French town. With a median age of 46.9, Boullay-les-Troux is older than 69% of compared French towns.
Women and men · all residents
47% women, 53% men
About 111 men for every 100 women. Median share of women: Essonne 51.3%, France 51.8%.
One-person households: 16%, a lower share than 99% of compared French towns
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 Essonne median and the France median
Living alone · share
On average, 2.6 people share a household. As a reference point, just over a third of households are one person living alone in the typical compared French town. Boullay-les-Troux has fewer single-parent households than 95% of compared French towns, at 6.1%.
Boullay-les-Troux ranks below 75% of compared French towns on empty homes: 5%
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
Some 5.4% of households are newcomers of under two years, against 26% who have been there 30 years or more. 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. Locally, 2.3% of homes are second homes.
Per consumption unit, the median standard of living is €42,590 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.
Per consumption unit, half of residents live on more than €42,590 a year: higher than in 99% of compared French towns.
Boullay-les-Troux ranks above 80% of compared French towns on households headed by a retired person: 39%
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
Households headed by a manual worker are rarer here than in 99% of compared French towns. On average, nearly a third of households are headed by a retired person in the typical compared French town.
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
Immigrants make up 9.6% in Boullay-les-Troux, more than in 69% of compared French towns
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.
About one in 20: that is how common foreign nationals are in Boullay-les-Troux (5%). Measured more widely, 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.
Married residents make up 63% in Boullay-les-Troux, more than in 99% of compared French towns
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
17% of residents 15 and over are single, against 25% in the typical compared French town. For married residents, the comparison in the typical compared French town is 43%.
In Boullay-les-Troux, 64% of adults out of school hold a higher-education qualification, more than in 98% 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
In the typical compared French town, the share of adults with no qualification is 19%; Boullay-les-Troux has 5.8%. The wider picture: 30% of adults out of school hold a higher-education qualification in the typical compared French town.
The 15th oldest of 41 French towns of 624 to 2,582 people
The 40 compared French towns nearest in population, by median age. Hover for each one’s second homes and immigrants; click for its page.
Ages run from 37.2 in Villejust to 62.3 in Prayssac.
1 of 6 neighbors are older than Boullay-les-Troux
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
| Town | Median age | 65+ | Second homes | Immigrants |
|---|---|---|---|---|
| Boullay-les-Troux | 46.9 | 20% | 2.3% | 9.6% |
| Chevreuse 5,502 · 2.1 mi | 46 | 21% | 4% | 10% |
| Saint-Rémy-lès-Chevreuse 7,747 · 2.3 mi | 47.7 | 24% | 4.2% | 11% |
| Limours 6,517 · 2.6 mi | 44.2 | 21% | 1.7% | 12% |
| Gif-sur-Yvette 22,544 · 3.3 mi | 40 | 19% | 3.5% | 14% |
| Magny-les-Hameaux 9,386 · 3.5 mi | 39.3 | 14% | 4.7% | 11% |
| Forges-les-Bains 4,241 · 3.8 mi | 39.5 | 15% | 2.2% | 8.6% |
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 Boullay-les-Troux
What is the population of Boullay-les-Troux?
624 at INSEE’s 2023 census, 1% fewer than in 2012 (632).
How old are Boullay-les-Troux’s residents?
The median age is 46.9, older than 69% of compared French towns. 22% are under 18 and 20% 65 or older.
How many second homes are there in Boullay-les-Troux?
6, with occasional dwellings: 2.3% of all homes, against 2.1% for the median compared French town.
How many immigrants live in Boullay-les-Troux?
INSEE counts 60 immigrants (born abroad, not French at birth), 9.6% of residents, and 31 foreign nationals (5%). The medians of compared French towns are 6.5% and 4.3%.
What is the median income in Boullay-les-Troux?
€42,590 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 8, 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.