About How Noisy?

This site answers one question: how noisy is this postcode?We take England's official road and rail noise model — published as specialist GIS files most people can't open — and translate it into plain English for every postcode.

Where the data comes from

Our noise levels come from the DEFRA Strategic Noise Mapping, Round 4 (2022), produced under the Environmental Noise (England) Regulations 2006 and published under the Open Government Licence. DEFRA models noise from major roads (roughly, those carrying over 3 million vehicle passages a year), major railwaysand large urban areas, on a 10-metre grid across England. Postcode locations come from Ordnance Survey's Code-Point Open; town and city locations from OS Open Names.

Two measures are modelled: LAeq,16h — the average level across the day (07:00–23:00) — and Lnight — the average across the night (23:00–07:00). Both are annual averages, expressed in decibels (dB).

How we process it

We look up the modelled level at each of England's 1,492,853 postcode centre points, for road and rail, day and night, and convert each value into the standard reporting bands used by DEFRA (55.0–59.9 dB, 60.0–64.9 dB and so on, starting at 50 dB for night). A postcode covers several addresses — the level at your exact front door can differ from the postcode centre, especially where a building screens the road.

Limitations — read this before relying on the data

• It's a model, not a measurement. Nobody put a microphone at your postcode. The model estimates long-term averages from traffic flows, terrain and building data.
• Major sources only. Local streets below the traffic threshold, neighbours, music venues, construction and industrial sites are not modelled. Aircraft noise is published separately per airport and is not yet included (we plan to add it).
• Absence of mapped noise is not silence. A postcode with no band simply falls outside the modelled contours of major sources.
• 2022 vintage.The model reflects 2022 conditions. Roads built or widened since, new developments and traffic changes won't show. DEFRA remaps every five years; the next round is expected around 2027, and we'll update when it lands.
• Annual averages smooth peaks. A 60 dB average can include much louder individual moments (a motorbike at 2am) and quieter spells.

Who runs this

How Noisy? is an independent site built on open government data. It is part of a family of public-data tools that includes TPO Search (tree preservation orders) and 106 Tracker (Section 106 developer contributions). We are not affiliated with DEFRA or any government body, and this site is not an official noise assessment.

Report an error

If something looks wrong — a postcode in the wrong place, a band that doesn't match DEFRA's published maps, a typo — tell us and we'll fix it.

Want the underlying data? See API & data access.

Noise data © Department for Environment, Food & Rural Affairs copyright and/or database right 2023, Open Government Licence v3.0. Contains OS data © Crown copyright and database right 2026 (Code-Point Open, OS Open Names).