Flats make up 1.5% in Les Trois Lacs, less than in 99% of compared French towns
In Les Trois Lacs, nearly a quarter of households are headed by a manual worker, beside 14% in the typical compared French town. The 2023 Census put the town’s population at 1,735, in 700 households. Put another way, about one in 33: 3% of households have no car. 7.1% of households are single parents, a lower share than in 88% of compared French towns.
Throughout this page, the Eure 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 Les Trois Lacs
One home in nine is a second home
The census counted 92 second homes and occasional dwellings in Les Trois Lacs, 11% of its 830 homes: higher than in 89% of compared French towns. 99% of them are houses. Their owners live elsewhere, so they aren’t in the population figures on this page. Homes & cars ↓
An older town
Half of Les Trois Lacs’ residents are under 51.5 and half over; the median of compared French towns is 44. 30% are 65 or older (France median 22%), 11% 80 or older. Ages ↓
Written from INSEE’s census 2023 on this page, against compared French towns.
Les Trois Lacs ranks above 89% of compared French towns on second homes: 11%
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
5.1% of households moved in less than two years ago; 32% have been in their home 30 years or more. As a yardstick, 2.1% of homes are second homes in the typical compared French town. Households in social housing are rarer here than in 99% of compared French towns. Empty homes: 5.7% here and 6.7% in the typical compared French town.
Les Trois Lacs changed by −4% from 2012 to 2023, behind 84% of compared French towns
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 change was −1%; from 2017 to 2023, −3%.
Les Trois Lacs is older than 88% of compared French towns: a median age of 51.5
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ Les Trois Lacs 51.5. The median compared French town: 44.
Where 11% of residents are 15 to 24 in the typical compared French town, Les Trois Lacs has 9.2%. In Les Trois Lacs, 30% of residents are 65 or over.
Women and men · all residents
52% women, 48% men
About 92 men for every 100 women. Median share of women: Eure 52.5%, France 51.8%. Women live longer than men, so towns with many older residents have more women.
A lower share of one-person households than 86% of compared French towns, at 28%
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 Eure median and the France median
Living alone · share
Households here average 2.3 people each. The usual figure: 35% of households are one person living alone in the typical compared French town. More couples with children than in 71% of compared French towns: 29%.
Median standard of living: €28,170 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 midpoint of living standards here is €28,170 a year per consumption unit, higher than in 72% of compared French towns.
6.6% of households are headed by a manager or professional, fewer than in 71% 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
Here 36% of households are headed by a retired person, where the figure in the typical compared French town is 32%. As a yardstick, nearly one in ten households are headed by a manager or professional in the typical compared French town.
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
Below 96% of compared French towns: 1.5% of residents are immigrants
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.
In Les Trois Lacs, 1% of residents are foreign nationals, beside 4.3% in the typical compared French town. As a reference point, 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.
Les Trois Lacs sits below 99% of compared French towns for single residents (17%)
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
Compared with 43% in the typical compared French town, 49% of residents 15 and over are married here. The share of single residents in the typical compared French town is 25%.
Adults with no qualification: 30%, a higher share than 91% 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
With graduates of higher education at 22%, Les Trois Lacs is behind four fifths of compared French towns on that count. For adults with no qualification, the comparison in the typical compared French town is 19%.
41 French towns of 1,735 to 2,582 people: this is the 10th oldest
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.
Every neighbor is younger than Les Trois Lacs
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
| Town | Median age | 65+ | Second homes | Immigrants |
|---|---|---|---|---|
| Les Trois Lacs | 51.5 | 30% | 11% | 1.5% |
| Le Val d'Hazey 5,111 · 3.2 mi | 42.7 | 19% | 1.4% | 8.3% |
| Gaillon 6,746 · 4.2 mi | 39.3 | 20% | 1.2% | 15% |
| Les Andelys 7,706 · 4.7 mi | 45 | 24% | 3.6% | 5.7% |
| Le Vaudreuil 3,624 · 6.2 mi | 46.3 | 24% | 2.5% | 4.4% |
| Val-de-Reuil 13,245 · 6.4 mi | 32.3 | 9.8% | 0.5% | 17% |
| Louviers 18,705 · 7.3 mi | 40.2 | 20% | 1.6% | 11% |
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 Les Trois Lacs
What is the population of Les Trois Lacs?
1,735 at INSEE’s 2023 census, 4% fewer than in 2012 (1,805).
How old are Les Trois Lacs’ residents?
The median age is 51.5, older than 88% of compared French towns. 19% are under 18 and 30% 65 or older.
How many second homes are there in Les Trois Lacs?
92, with occasional dwellings: 11% of all homes, against 2.1% for the median compared French town.
How many immigrants live in Les Trois Lacs?
INSEE counts 26 immigrants (born abroad, not French at birth), 1.5% of residents, and 17 foreign nationals (1%). The medians of compared French towns are 6.5% and 4.3%.
What is the median income in Les Trois Lacs?
€28,170 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 9, 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.