Heathrow north-west runway · 3,500 m
What would a third runway at Heathrow mean where you live?
This site estimates where aircraft would fly, how loud they would be and how often you would hear them, today and with a third runway. It also estimates the effect on home values. Enter a postcode or tap the map to see the figures for any location within about 40 km east and 25 km west of the airport.
Your postcode is looked up in your browser and is not sent anywhere.
The scale of the change
- Flights a year
- 480,000 today (legal cap)
- 756,000 with third runway (Heathrow proposal)
- Area above 54 dB daytime average
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- Area above 51 dB daytime average
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Flight numbers: Heathrow's 2025 proposal. Areas: this site's model, calibrated to the 2024 figure in the government's draft policy statement. See Method.
What the site shows
Noise map
Estimated average daytime aircraft noise across west, south-west and central London and the Thames Valley, with the main noise contours. Switch between today, with a third runway, and the change between the two.
Your postcode
Average noise, the number of flights a day louder than 60 and 65 dB, and how high arriving and departing aircraft typically are near you. The lookup happens in your browser; your postcode is not sent anywhere.
Home values
A range for the possible change in home values, based on published research on noise and house prices and the median price in your neighbourhood. It is an estimate for an area, not a valuation of any home.
By constituency
Households above 54 dB and the estimated total change in home values in each parliamentary constituency, with a draft email to the local MP.
How to use it
- Open the map and enter your postcode, or tap any location.
- Compare today with the third-runway case using the buttons above the map.
- Read the figures in the panel, then see the constituency page to compare your area with others.
What the numbers mean
- LAeq,16h
- The average sound level from 07:00 to 23:00 on an average summer day. It is the main measure the UK government uses for aircraft noise.
- 51 dB
- The level at which government policy says adverse effects on health and quality of life begin.
- 54 dB
- The level government policy treats as the onset of significant community annoyance.
- N65 and N60
- The number of flights a day that are louder than 65 or 60 dB at their peak. A normal conversation is about 60 dB.
What is not yet known
The flight paths for a third runway have not been designed. Routes will be set through the Civil Aviation Authority's airspace change process, after planning decisions. Until then this site uses generic paths: straight-in arrivals and departures that fan out after take-off. They show the general pattern of noise, not where specific routes will go.
The estimates will be updated with the indicative routes in Heathrow's statutory consultation, and again as official designs are published.
Key dates
- Government announces support for a third runway.
- Draft Heathrow Expansion National Policy Statement published.
- Heathrow's statutory consultation on its proposals. How to respond.
- End of parliamentary scrutiny of the draft policy statement, before a vote.
- Decision on planning consent (Development Consent Order).
- Earliest opening; recent reports suggest nearer 2039.
About this site
This is an independent information site. It is not affiliated with Heathrow Airport Ltd, the Department for Transport, the Civil Aviation Authority or any campaign. The method and assumptions are published in full so that anyone can check them. Campaign groups and official sources are listed on the Get involved page.