Ermont · report
Renovation in Ermont
In 2025, 43% of the homes authorised were in existing buildings: conversions, extensions and changes of use.
- Homes in existing buildings, 2025
- 43%
Homes authorised in Ermont: new buildings and existing ones
Dwellings authorised each year, by the year the permit was granted: in new buildings, and by works on existing buildings (conversions, extensions, changes of use). SDES Sitadel.
- Existing buildings
- New buildings
Show the numbers
| Year | New buildings | Existing buildings | Total |
|---|---|---|---|
| 2025 | 4 | 3 | 7 |
| 2024 | 335 | 8 | 343 |
| 2023 | 9 | 4 | 13 |
| 2022 | 2 | — | 2 |
| 2021 | 188 | 6 | 194 |
| 2020 | 17 | 12 | 29 |
| 2019 | 9 | 3 | 12 |
| 2018 | 222 | 5 | 227 |
| 2017 | 30 | 4 | 34 |
| 2016 | 27 | — | 27 |
| 2015 | 17 | — | 17 |
| 2014 | 250 | 1 | 251 |
| 2013 | 60 | — | 60 |
Only permits that create dwellings are listed, so renovation that adds no home (refurbishing, insulating, re-roofing) is not counted. A permit is permission to build, not a finished home. The current year is left out until it is complete.
Other reports for Ermont
At the median sale price, a 90 m² home costs €358,200. With 10% down and a 30-year mortgage, the payment is €1,394 a month. The HCSF caps it at 35% of a household's income.
- Payment, two incomes
- 30%
- Payment, one income
- 60%
Owning a 90 m² apartment costs less each month than renting it. Owning counts interest, running costs and the return the deposit could earn, at apartments' median sale price; rent is the asking rent. Repaying the loan is saving, so it is left out.
- Rent per month
- €1,714
- Owning per month
- €1,229
Figures for Val-d'Oise: Ermont has no reliable figures of its own.
32.3% fewer homes were licensed for construction in the last 12 months than in an average year of the past decade.
- Licensed, 12 months
- 4,869
In 2022 the population grew by 300 while 176 homes were started: 1.7 new residents for every new home.
- New residents per new home, 2022
- 1.7
- Population change, 2022
- +300
3.0% of the 13,233 homes counted in the 2023 census stood empty, whether for sale, to let or for other reasons.
- Empty, 2023 census
- 3.0%
- Empty homes
- 401