— Île-de-France · Yvelines · 21,268 inhabitants
Public indicators aggregated at commune level: housing market, services, safety, environment. Official sources, updated as of May 2026.
Per-theme summary derived from sourced indicators. Tap a theme for the detail.
Synthetic indicators. Sourced thematic detail below.
Median price per m²
4 381 €/m²
last 5 years of recorded sales
DVF — DGFiP · 2025
Rank 210 of 240 communes in the Yvelines département
See detail →Energy-sieve homes (EPC F or G)
9 %
share of poorly-insulated private homes
ADEME · 2026
Rank 56 of 260 communes in the Yvelines département
See detail →GP access (APL)
3,3 c/an/hab
DREES index — under-served threshold = 2.5
DREES · 2024
Rank 32 of 259 communes in the Yvelines département
See detail →Fiber rollout
98 %
fiber-eligible homes
ARCEP · 2025
Rank 186 of 259 communes in the Yvelines département
See detail →Average social index of public schools
126
DEPP index — national median = 100 ; favored >115, disadvantaged <85
DEPP · 2024
Rank 111 of 214 communes in the Yvelines département
See detail →Recorded crime
46,7 / 1 000 hab/an
offences recorded by law enforcement
SSMSI · 2024
Rank 440 of 517 communes in the Yvelines département
See detail →Water hardness
20 °f
soft <15, medium 15-30, hard 30-40, very hard >40
SISE-Eaux ARS · 2025
Rank 57 of 208 communes in the Yvelines département
See detail →Median disposable income
26 750 €/UC/an
per consumption unit
Filosofi — INSEE · 2020
Rank 405 of 512 communes in the Yvelines département
Poverty rate
12,0 %
households below the monetary poverty line
Filosofi — INSEE · 2025
Rank 127 of 170 communes in the Yvelines département
Population change
+16,0 % / 5 ans
cumulative variation INSEE census (2017→2022)
INSEE RP · 2025
Rank 5 of 259 communes in the Yvelines département
4 381 €/m²
Median over 399 sales (2025)
From 2 440 €/m² to 5 691 €/m² depending on the area, across 703 sales.
DVF median of recent notarial transactions. French median ≈ €2,800/m². Cross-check with DPE and listing age to estimate negotiation margin.
Source: DVF — DGFiP
19,6 €/m²/mois
Median rent per m² observed by ANIL observatories. Compare with purchase price for gross rental yield.
Source: ANIL Observatoires des loyers · 2025Reliability high
9 %
Share of homes labelled F or G in the surveyed stock (French median ≈ 18%). Climate Act: rental ban for G in 2025, F in 2028, E in 2034.
Source: ADEME Observatoire DPE · 2026Reliability high
61,2 %
of territory in U or open AU zones
Share of commune area classified as buildable in the local plan (urban U zones + open to-urbanise AUc zones). The precise rules — height, footprint, setback — depend on the exact zone of the parcel.
Source: Géoportail de l'Urbanisme (GPU)Reliability high
59,9 %
of territory already urbanised
Share of area in U zones of the local plan — already-urbanised sectors, open to immediate construction subject to the zone rules.
Source: Géoportail de l'Urbanisme (GPU)Reliability high
76
PLU zoning areas
The commune has a digitised PLU/PLUi published on the Géoportail de l'Urbanisme, split into 76 zones. Without a PLU, the National Planning Regulation (RNU) applies.
Source: Géoportail de l'Urbanisme (GPU)Reliability high
Zoning from the Géoportail de l'Urbanisme (GPU). Indicative at commune scale — for the buildability of a precise parcel, consult the PLU at the town hall.
3,28
consultations / year / inhabitant
DREES APL indicator — French median ≈ 3.5. Tension threshold at 2.5: below this level, the commune is a medical desert.
Source: DREES Indicateur APL · 2024Reliability high
126
Weighted average Social Position Index (DEPP). French median ≈ 102. Sociological reading, not pedagogical quality.
Source: DEPP IPS écoles · 2024Reliability high
98 %
Share of premises reachable by optical fibre (ARCEP). French median ≈ 75%. Tenant-attraction lever and near-mandatory residential criterion in 2026.
Source: ARCEP Observatoire fibre · 2025Reliability medium
47
per 1,000 inhabitants
Offences recorded by police/gendarmerie (French median ≈ 35). Includes property, personal and drug offences. Honest reading: compare to neighbouring communes.
Source: SSMSI — Ministère de l'Intérieur · 2024Reliability medium
5
ICPE within 1 km (average)
Average number of classified facilities (ICPE) within 1 km around the commune (DGPR). Seveso = major industrial risk, ICPE = facilities subject to authorisation/registration.
Source: DGPR Géorisques · 2025Reliability high
20 °f
Hydrotimetric titre (French median ≈ 22 °f). Below 15 = soft ; 22-32 = hard ; above = very hard (scaling, energy overconsumption).
Source: ARS — SISE-Eaux · 2025Reliability medium
0,5 kg/ha
Phytosanitary sales per cultivated hectare at département level (French median ≈ 1.2 kg/ha). Exposure indicator for residents.
Source: BNV-D (OFB) · 2023
1418 kWh/m²/an
Annual horizontal solar irradiation (PVGIS). French median ≈ 1,320 kWh/m²/year. Above 1,500 = very favourable (8-10 year ROI for panels), below 1,100 = longer ROI (12-15 years). MaPrimeRénov subsidy + self-consumption available.
Source: PVGIS European Commission · 2023Reliability high
— Live calculations
On this page, 6 calculations with the real figures for Saint-Cyr-l'École: whether to buy or rent, how much to negotiate, the monthly mortgage payment, the net rental yield, the monthly cashflow and the energy bill.
Method and assumptions detailed in Transparency.