Autonomy score methodology
A transparent model built on public data: reproducible estimates, with every formula and source published below.
Updated on
4
pillars
≈ 35,000
French municipalities
5
public data sources (France)
100%
transparent
What the score measures
The Azimut autonomy score quantifies the residential resilience potential of a household: its capacity to produce energy, collect and recycle water, and source fresh food from its own physical characteristics and installed systems. It is a potential performance indicator, not a real consumption audit.
Each pillar is calibrated against reference values published by recognised organisations (European Commission JRC, INRAE, ADEME/CSTB, Eurostat). Calculation parameters are aligned with sector standards in force for sustainable housing.
The 4 Pillars of Autonomy
Energy
What it measures
This pillar evaluates a household's photovoltaic solar production capacity based on its roof characteristics and the real solar irradiation at its precise geographic location, compared to its annual electricity consumption — declared or estimated.
Data & calibration
Solar irradiation comes from the European Commission's PVGIS API (JRC), queried for your home's coordinates: these are historical data derived from satellite measurements, not real-time readings; if PVGIS does not respond, a geographic estimate is used instead. The yield used is net: PVGIS deducts 14% system losses (cables, inverter…, its default value) as well as temperature losses.
Why this weight
Energy carries the highest weight (40%) because it delivers the most direct, measurable, and immediate return on investment for the majority of European households.
Water
What it measures
This pillar evaluates a household's capacity to cover part of its non-potable water needs (sanitation, irrigation, washing) through rainwater harvesting via its roof, supplemented where applicable by a greywater system or well.
Data & calibration
Coverage caps by climate zone come from the ADEME/CSTB rainwater-harvesting guide. Annual rainfall is taken at the home's coordinates (ERA5 climate reanalysis, via Open-Meteo) when available; otherwise from an estimate by broad climate zone, and as a last resort from a default of 700 mm per year.
Why this weight
Water carries 25% of the score. Its growing scarcity under climate change — particularly in Mediterranean and continental zones — makes it a major resilience issue for the coming decades.
Food
What it measures
This pillar evaluates a household's fresh fruit and vegetable production capacity based on its cultivable garden area, the presence of a greenhouse or small livestock, measured against the standard dietary needs of its occupants.
Data & calibration
The food-requirement reference (annual fresh fruit and vegetables per person) is the one published by INRAE in its sustainable-food framework. The reference yield-per-area comes from experimental measurements on market gardens of comparable size.
Why this weight
Food carries 20% of the score. Local fruit and vegetable production is the most accessible autonomy lever for the majority of homeowners, with a strong impact on food carbon footprint and logistical resilience.
Heating
What it measures
This pillar evaluates the share of heating needs covered by low-carbon solutions — heat pump, wood or pellet stove, solar heat — weighted by the home's insulation quality.
Data & calibration
Reference heating needs come from RE2020/RT2012 (EU) and EIA RECS (US) standards, adjusted to local heating degree-days. Heat-pump performance uses a COP of 3.5 (ASHRAE 90.1).
Why this weight
Heating carries 15% of the score. It is often the household's largest energy expense; reducing it through insulation and renewable heat has a strong impact on autonomy and carbon footprint.
The calculation pillar by pillar, weights included: home autonomy calculator (in French)
What your score means
0–29
Getting Started
Your home is grid-dependent. High potential for quick wins.
30–59
Growing
You've started producing your own resources. Big gains possible with targeted investment.
60–79
Advanced
Significant autonomy achieved: own production across several pillars, and grid dependence clearly reduced.
80–90
Champion
Near-complete autonomy. You're a model for resilient living.
Each pillar is capped at 95 (food at 70), so the overall score never exceeds 90. Full autonomy is a journey, not a checkbox.
Your priority: savings, ecology or autonomy
The priority selector is the simulator's lens. It never changes what we MEASURE (your current autonomy, computed from your equipment): it changes what we RECOMMEND — the size of the setup, hence the achievable score, the savings and the action plan.
| Lever | Money SavingFastest ROI | Eco-FriendlyLowest footprint | AutonomyMax independence |
|---|---|---|---|
| Goal | Spend as little as possible: solar is sized to the fastest-payback slice, rainwater harvesting is left out. | Minimise carbon: in between, favouring clean production (solar, garden) without over-provisioning the battery. | Rational maximalist: every dimension is oversized, then pulled back under a 25-year payback. |
| Recommended solar | × 0.7 of your needs | × 1.1 of your needs | × 1.4 of your needs |
| Rainwater harvesting | Left out — a tank pays back in over a hundred years | × 1.2 of your needs | × 1.4 of your needs |
| Vegetable garden | × 0.5 of your needs | × 1.3 of your needs | × 1.5 of your needs |
| Heating (targeted autonomy) | 35% targeted | 85% targeted | 90% targeted |
| Catalogue tier | One tier below your slider | Your slider's tier | One tier above your slider |
| Payback guardrail | None — sizing follows your needs | None — sizing follows your needs | Payback capped at 25 years |
“Your needs” = the system your home actually calls for (consumption, roof, rainfall, occupants), computed by the savings engine. The factor applies to it, multiplied by your ambition slider, and never below what you already own. Achievable energy, water and food scores then follow from those sizes through the same physics as the current score; heating, with no sized system, carries a target per priority.
Switching priority replaces the plan
Your action plan is reset to the recommended setup for the new priority — the dialog says so before you confirm — and achievable scores and savings are recomputed from that plan.
Measured never moves, installed never shrinks
Your current autonomy is identical under all three lenses: the priority sizes a recommendation, not a measurement. And a recommendation never drops below equipment you already own.
Savings ≤ Ecology ≤ Autonomy
On every pillar the achievable score grows in that order — autonomy is the documented ceiling. A pillar already saturated by the ecology setup has no headroom left: autonomy leaves it there rather than over-reporting.
European baseline comparison
Baseline derived from Eurostat residential energy data and JRC autonomy studies.
Our data sources
The Azimut model is built entirely on public data from European and national reference organisations. No proprietary data or private statistical models are used. Every source can be consulted directly.
JRC PVGIS
European Commission
Used for
Annual solar irradiation (kWh/m²/yr) by GPS coordinates, integrated into each energy score calculation in real time.
Why it's authoritative
The European Commission's solar reference database, built on 15+ years of MERRA-2 and CMSAF satellite measurements.
CORINE / Defra
Copernicus (UKCEH LCM alt.)
Used for
Reference data on market-garden food production and annual per-person requirements for fresh fruit and vegetables.
Why it's authoritative
France's national public research institute for agriculture, food and the environment — the leading scientific body on these subjects.
Met Office
© Crown Copyright
Used for
Regulatory rainwater-coverage caps by climate zone, plus carbon-impact ratios for the circularity pillar.
Why it's authoritative
France's ecological transition agency — its technical guides are the reference for the sustainable-building sector in France.
EA / SEPA / NRW
Environment Agency / SEPA / NRW
Used for
Average residential electricity prices by country (updated annually), used to compute projected financial savings.
Why it's authoritative
The statistical office of the European Union — the official source of energy-price data harmonised across the continent.
Ofgem
Office of Gas & Electricity Markets
Used for
Geolocated natural-hazard data (flooding, earthquake, radon, wildfire) used in the Risk Exposure section.
Why it's authoritative
Géorisques is the official national platform of France's Ministry of Ecological Transition, fed by the BRGM geological survey.
French municipality pages: what is estimated, and how
The French municipality pages show three figures computed from the municipality's coordinates alone, with no on-site measurement. They are estimates; here is exactly how they are obtained.
Heating: heating degree days (HDD)
HDD ≈ 1,500 + (latitude − 42) × 180
Base 18 °C, latitude in degrees, result bounded between 1,500 and 4,200. Saint-Pierre-et-Miquelon, with its cold climate, gets 4,200 HDD. In the French Caribbean, French Guiana, the Indian Ocean and the Pacific there is no heating need: the dimension then covers solar hot water and summer comfort.
Water: annual rainfall
- Provence, Côte d'Azur, eastern Languedoc and Corsica600 mm
south of 44.3° N and east of 3.2° E
- Brittany and the far west (Nantes, Vendée, Cotentin, Basque coast)1,000 mm
west of 1.2° W
- South-west (Aquitaine, Charente, Gascony, Béarn, Bigorre)900 mm
south of 45.8° N and west of 1.2° E
- Rhône valley and Alps900 mm
south of 46.5° N and east of 4.8° E
- Rest of mainland France (north, east, Paris basin, Normandy, Poitou, Limousin, Massif Central, Toulouse area, Roussillon…)750 mm
every other municipality
One value per broad climate zone of mainland France, chosen from the municipality's latitude and longitude. The rules are checked in the order listed: the first one that applies sets the value. Overseas: one value per island coast.
Energy: solar yield
- 40° N1,600 kWh/kWp
- 43.3° N (Marseille)1,435 kWh/kWp
- 46° N1,260 kWh/kWp
- 48.5° N1,080 kWh/kWp
- 50.6° N (Lille)920 kWh/kWp
- 53° N870 kWh/kWp
Annual output per installed kWp, interpolated linearly by latitude between these PVGIS-calibrated points, then bounded between 650 and 2,000 kWh/kWp. Overseas: one value per island coast.
These three values are estimates: they are for comparing municipalities, not for sizing an installation. Your personal score queries PVGIS (European Commission, JRC) for your home's exact coordinates, and uses the rainfall at those coordinates (ERA5 reanalysis) when available.
Natural-hazard exposure: sources and limits
For a home in France, the natural-hazard overview separates two kinds of data: what an official Géorisques dataset says about the commune, and indicative estimates. Every card shows its source and its nature.
| Risk | Source | Scale | Granularity | Confidence |
|---|---|---|---|---|
| Flood, ground movement, forest fire, storm | Géorisques — GASPAR database (risks listed per commune) | Listed / not listed | Commune | Medium: official, but does not place the address in a zone |
| Earthquake | Géorisques — regulatory seismic zoning (in force since 1 May 2011) | Zones 1 to 5 | Commune | High: regulatory zoning |
| Radon | Géorisques — radon potential (IRSN map) | Categories 1 to 3 | Commune | Medium: the actual level depends on the building and must be measured |
| Heatwave, drought | Azimut AI estimate from latitude | Low to high (indicative) | Broad geographic area | Low: indicative estimate |
| Any other risk without an official answer | Azimut AI estimate from position (latitude, coastal band) | Low to high (indicative) | Broad geographic area | Low: indicative estimate |
Géorisques datasets are queried for mainland France, Corsica and the five overseas departments, and only from the home's geolocated point. Elsewhere, without a geolocated address, or when a dataset does not answer, the card concerned is an indicative estimate and the screen names the datasets that actually answered. Radon has no estimate: without an official answer, its card is left out.
What the overview does not assess
- The zoning of a risk prevention plan (PPRN, PPRI) at plot level.
- Clay shrink-swell (exposure map applicable since 1 July 2026).
- Natural-disaster (CatNat) decrees issued for the commune.
- Coastline retreat and volcanic risk.
- Technological risks (industrial sites, pipelines) and soil pollution.
None of these screens replaces the état des risques, the official risk statement to be appended to a sale or a lease in the areas concerned. errial.georisques.gouv.fr
Check the natural hazards at your address (France, page in French)Ready to calculate your score?
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