How a Sky Score is worked out
Type a postcode and you get five scores out of 10, and one overall score. This page shows where each number comes from, which one we estimate ourselves, and what none of them can tell you.
A score, taken apart
Each score is out of 10, and higher is better. The overall score multiplies each one by its weight and adds them up. Here is Hounslow, the council area next to Heathrow.
| Score | Out of 10 | Weight | Points |
|---|---|---|---|
| Quiet Skies area band | 0.0 | 32% | 0.00 |
| Affordability official data | 2.1 | 27% | 0.57 |
| Price growth official data | 3.7 | 0% | 0.00 |
| Liveability official data | 7.2 | 27% | 1.94 |
| Environment official data | 6.5 | 14% | 0.91 |
| Overall score | 100% | 3.4 |
Quiet Skies is 32% of the score in this view. At 0.0 next to an airport, 3.2 of the 10 possible points are out of reach before anything else is counted.
For a whole council area, Quiet Skies is a band we set from the aircraft noise across it. A postcode inside Hounslow gets its own figure instead, so scores change from street to street. The points are each score times its weight; the overall score is their total, rounded to one decimal place.
The five scores
- Quiet Skies
- How free a place is from aircraft noise. 10 is the quietest. Where the government's official noise map covers a postcode, we use its figure. Everywhere else, we estimate it from the published flight routes.
- Affordability
- How cheap homes are, from the average price in the council area, compared with every council area we cover. 10 is the cheapest.
- Price growth
- How much prices rose over the last year, after inflation. Only the investor view counts it.
- Liveability
- Crime, school results, rail, metro and tram stations within an 800 metre walk (about ten minutes), and GP surgeries within 500 metres.
- Environment
- Air quality, road noise and flood risk.
A score always rises when a place is better, and is named for the good thing: Quiet Skies 8 out of 10. Some views turn the same reading round and name it for the bad thing: Aircraft noise 2 out of 10. It is one reading, shown two ways.
Official data, and our own work
Almost every number comes straight from a public body's own published data. Quiet Skies is the exception: we work it out, and every answer says how.
Our own work: Quiet Skies
Where the official noise map has a figure for a postcode, we use it. Where it has none, we estimate it from the flight routes published in the UK Aeronautical Information Publication (NATS): how close a postcode is to the routes and the runway, and how big the airport is. A whole council area gets a band we set from the noise across it. Where both exist, we check our estimate against the official map and publish how far off it is on the API page.
Official data
Prices from HM Land Registry, crime from the Office for National Statistics, school results from the Department for Education, stations from the Department for Transport, GP surgeries from the NHS, air quality and noise from DEFRA, and flood risk from the Environment Agency.
Some official data is itself a model, not a reading at your door. DEFRA's air quality and noise maps and the Environment Agency's flood map are worked out by those bodies from measurements and computer models.
The overall score
Different people care about different things, so there are eight views. Each gives the five scores different weights, and a weight of 0% means that score is not counted in that view. Choose a view on the full map and the overall score changes; the five scores stay the same.
| View | Quiet Skies | Affordability | Price growth | Liveability | Environment |
|---|---|---|---|---|---|
| Balanced | 32% | 27% | 0% | 27% | 14% |
| Family | 18% | 18% | 0% | 46% | 18% |
| Investor | 9% | 26% | 34% | 17% | 14% |
| First-Time | 16% | 43% | 0% | 27% | 14% |
| Quiet Life | 48% | 19% | 0% | 19% | 14% |
| Renter | 26% | 30% | 0% | 30% | 14% |
| Commuter | 21% | 30% | 0% | 35% | 14% |
| Later life | 36% | 14% | 0% | 32% | 18% |
When a score can't be worked out, for example where no school results are published, we leave it out and share its weight among the others. We never fill a gap with a typical value, and the answer says what is missing. Liveability and environment each need at least two of their parts, or that score is left out.
What it can't tell you
- How often planes fly over. The flight routes show where aircraft fly, not how many of them do.
- Anything about one particular home, such as its condition or its value.
- Which floor a home is on. The figures are for the postcode near ground level. Road noise and traffic pollution can be quite different on an upper floor; aircraft noise changes little from floor to floor.
- Whether a place is right for you. It is information to help you look, not advice.
- It is not a survey, a valuation or a conveyancing search, and does not replace any of them.
- Shares are of postcodes, not homes. "30% of postcodes" counts postcodes, and one postcode can hold one home or fifty.
Where the data comes from
- Prices: HM Land Registry, UK House Price Index. Contains HM Land Registry data © Crown copyright and database right 2026. This data is licensed under the Open Government Licence v3.0.
- Crime: Office for National Statistics, Crime in England and Wales. Open Government Licence v3.0.
- Schools: Department for Education, Key Stage 4 Progress 8. Open Government Licence v3.0.
- Stations: Department for Transport, National Public Transport Access Nodes (NaPTAN). Open Government Licence v3.0.
- GP surgeries: NHS Organisation Data Service. Open Government Licence v3.0.
- Air quality and noise maps: DEFRA. Open Government Licence v3.0.
- Flood risk: Environment Agency, Risk of Flooding from Rivers and Sea. Open Government Licence v3.0.
- Postcodes: Office for National Statistics, National Statistics Postcode Lookup, under the Open Government Licence v3.0. Contains OS data © Crown copyright and database right; Royal Mail data © Royal Mail copyright and database right; National Statistics data © Crown copyright and database right.
- Flight routes: UK Aeronautical Information Publication (NATS), drawn by Sky Score for the aircraft noise estimate. Public, but not openly licensed, and not for navigation.
Each licence covers its own dataset, not Sky Score as a whole.
How up to date it is
- House prices are HM Land Registry's monthly price index, now for August 2026. We update them each month.
- Noise maps are DEFRA's latest, published in 2022. They describe 2021, a year with fewer flights and less traffic than usual, so they read quieter than today.
- Air quality is DEFRA's latest map of yearly averages.
- Crime is the Office for National Statistics' latest year, updated when it publishes.
- School results are the latest Progress 8 figures. The government has paused the measure for two years, so these stay until it returns.
- Flight routes are rebuilt from the official aeronautical publication and checked on every release.
Places we don't cover yet
Sky Score covers 97 council areas in 13 UK city regions, plus New York's 5 boroughs and 50 Bay Area cities (facts only, with no score on the site yet).
Outside these places a postcode answers "not covered yet", and we don't guess. A score built from another city's figures would be wrong in a way you couldn't see.
For every threshold and its source, read the full methodology. Developers can get the same scores, with their sources, from the API.