# SL4

Postcode district covering Windsor and Dedworth, in Windsor and Maidenhead.

SL4 is a postcode district covering Windsor and Dedworth, in Windsor and Maidenhead. Median sale price £517,250 in 2025. Recorded crime 83.8 per 1,000 people.

Postcode district. Code SL4. In: [Postcodes](https://openindex.co.uk/postcode) › [SL](https://openindex.co.uk/postcode/sl)

Approximate outline worked out by Open Index from the ONS Postcode Directory: each census output area belongs to the district that holds most of its postcodes. People, homes, recorded crime and broadband add up those output areas. House sales count every sale with an SL4 postcode. [How census figures are added up](https://openindex.co.uk/sources/population)

## Key figures

- **Median sale price: £517,250** (2025). The median price paid for a home in SL4 was £517,250 in 2025. 251st most expensive of 2,235. Source: Worked out by Open Index from HM Land Registry Price Paid Data. Published 28 September 2026. https://openindex.co.uk/postcode/sl4#f-house-sales-median-price
- **Population: 45,871** (2021). SL4 had 45,871 usual residents at the census (ONS Census 2021). 289th most populated of 2,756. Source: Census 2021, England and Wales and Scotland's Census 2022 and Census 2021, Northern Ireland, 2021. Published 21 July 2026. https://openindex.co.uk/postcode/sl4#f-population
- **People in radon Affected Area squares: 23%** (2022). About 23% of people in SL4 live in a 1 km square that the radon atlas marks as a radon Affected Area. UK 44%. Source: Worked out by Open Index from the UKHSA and BGS radon atlas and census output areas. Published 1 December 2022. https://openindex.co.uk/postcode/sl4#f-radon-affected-share
- **Gigabit broadband coverage: 83.5%** (January 2026). In SL4, 83.5% of homes and businesses could get gigabit-capable broadband in January 2026 (Ofcom). UK 87.8%. Source: Connected Nations (Ofcom), January 2026. Published 13 May 2026. https://openindex.co.uk/postcode/sl4#f-gigabit-coverage

## On the map

- [Radon Affected Area by postcode district](https://openindex.co.uk/map/radon-affected-areas?place=SL4) (Worked out by Open Index · 2022): About 23% of people in SL4 live in a 1 km square that the radon atlas marks as a radon Affected Area.
- [Sales per year by postcode district](https://openindex.co.uk/map/house-sales-per-year?place=SL4) (Worked out by Open Index · 2025): 582 homes were sold in SL4 in 2025.
- [Crime and ASB by postcode district](https://openindex.co.uk/map/recorded-crime?place=SL4) (Police recorded crime and outcomes (data.police.uk) · August 2026): Crime and anti-social behaviour for SL4.
- [Population by postcode district](https://openindex.co.uk/map/population?place=SL4) (Census 2021, England and Wales): SL4 had 45,871 usual residents at the census.

## How SL4 compares

Each postcode district against every other postcode district the measure covers.

| Measure | SL4 | Rank | Compared with |
| --- | --- | --- | --- |
| Median sale price | £517,250 | 5th cheapest | 10 postcode districts, SL · 2025 |
| Population | 45,871 | 5th most populated | 12 postcode districts, SL · 2021 |
| People in radon Affected Area squares | 23% | 6th most people in radon Affected Areas | 12 postcode districts, SL · 2022 |
| Gigabit broadband coverage | 83.5% | 3rd lowest | 12 postcode districts, SL · Jan 2026 |

## Is SL4 safe? What police records show

In the 12 months to August 2026, police recorded crimes and anti-social behaviour in SL4 at a rate of 83.8 per 1,000 people.
That compares with 77.9 per 1,000 people across the SL postcode area.
In August 2026 alone, 336 cases of crime and anti-social behaviour were recorded in SL4.
In the 12 months to August 2026, the most common types were violence and sexual offences (1,318), other crime (844) and anti-social behaviour (439).
A year earlier, the recorded crime rate in SL4 was 79.0 per 1,000 people.
Worked out by Open Index from police.uk crime records and ONS and NISRA population estimates.
Rates are per resident, so places that many people work in or visit, such as Westminster, the City of London and other city centres, have far higher rates than their residents alone would suggest.

## Deprivation in SL4, neighbourhood by neighbourhood

- Deprivation is ranked by neighbourhood, so SL4 has no single figure. Of its 25 neighbourhoods with a rank:
- Decile 4: 1 neighbourhood
- Decile 5: 1 neighbourhood
- Decile 6: 3 neighbourhoods
- Decile 7: 3 neighbourhoods
- Decile 8: 6 neighbourhoods
- Decile 9: 5 neighbourhoods
- Decile 10 (England’s least deprived 10%): 6 neighbourhoods

Source: English Indices of Deprivation 2025. Decile 1 is the most deprived tenth of neighbourhoods in England.

## Neighbourhoods in SL4

| Area | People (census) | Recorded crime per 1,000 | Deprivation decile | Gigabit broadband |
| --- | --- | --- | --- | --- |
| [Bracknell Forest 001C](https://openindex.co.uk/bracknell-forest/neighbourhood/e01016252) | 1,492 | 36.4 per 1,000 | 8 | 93.4% |
| [Windsor and Maidenhead 010A](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016544) | 2,004 | 389.1 per 1,000 | 8 | 48.1% |
| [Windsor and Maidenhead 010B](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016567) | 3,173 | 110.6 per 1,000 | 9 | 40.8% |
| [Windsor and Maidenhead 010C](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016568) | 1,283 | 47.7 per 1,000 | 7 | 99.8% |
| [Windsor and Maidenhead 010D](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016569) | 1,061 | 78.2 per 1,000 | 6 | 91.1% |
| [Windsor and Maidenhead 012A](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016545) | 2,117 | 103.5 per 1,000 | 7 | 64.1% |
| [Windsor and Maidenhead 012B](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016547) | 1,753 | 154.8 per 1,000 | 8 | 95.7% |
| [Windsor and Maidenhead 012C](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016550) | 1,484 | 38.5 per 1,000 | 9 | 94.5% |
| [Windsor and Maidenhead 012D](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016552) | 1,742 | 97.7 per 1,000 | 9 | 91.3% |
| [Windsor and Maidenhead 013A](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016551) | 1,581 | 58.3 per 1,000 | 10 | 98.1% |
| [Windsor and Maidenhead 013B](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016553) | 1,500 | 53.8 per 1,000 | 8 | 84.5% |
| [Windsor and Maidenhead 013C](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016557) | 1,944 | 78.6 per 1,000 | 8 | 94.3% |
| [Windsor and Maidenhead 013D](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016558) | 1,446 | 37.4 per 1,000 | 7 | 93.2% |
| [Windsor and Maidenhead 014A](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016548) | 1,903 | 35.7 per 1,000 | 10 | 80.3% |
| [Windsor and Maidenhead 014B](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016549) | 2,015 | 54.7 per 1,000 | 8 | 86.2% |
| [Windsor and Maidenhead 014C](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016554) | 1,775 | 70.5 per 1,000 | 5 | 96.5% |
| [Windsor and Maidenhead 014D](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016555) | 1,632 | 107.5 per 1,000 | 4 | 95.2% |
| [Windsor and Maidenhead 014E](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016556) | 1,867 | 61.7 per 1,000 | 6 | 95.4% |
| [Windsor and Maidenhead 015A](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016546) | 1,622 | 62.5 per 1,000 | 10 | 94.1% |
| [Windsor and Maidenhead 015B](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016595) | 1,834 | 50.1 per 1,000 | 9 | 89.6% |
| [Windsor and Maidenhead 015C](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016596) | 1,964 | 42.7 per 1,000 | 10 | 86.9% |
| [Windsor and Maidenhead 015D](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016597) | 1,722 | 49.0 per 1,000 | 10 | 80.0% |
| [Windsor and Maidenhead 016C](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016587) | 1,757 | 27.5 per 1,000 | 9 | 97.7% |
| [Windsor and Maidenhead 016D](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016588) | 1,826 | 81.6 per 1,000 | 6 | 88.3% |
| [Windsor and Maidenhead 016E](https://openindex.co.uk/windsor-and-maidenhead/neighbourhood/e01016589) | 1,739 | 59.8 per 1,000 | 10 | 80.3% |

## Your MP

- [Windsor](https://openindex.co.uk/constituency/windsor): Jack Rankin (Conservative), MP since July 2024. 89% of the people here.
- [Maidenhead](https://openindex.co.uk/constituency/maidenhead): Mr Joshua Reynolds (Liberal Democrat), MP since July 2024. 9.0% of the people here.
- [Beaconsfield](https://openindex.co.uk/constituency/beaconsfield): Joy Morrissey (Conservative), MP since July 2024. 1.5% of the people here.
- [Slough](https://openindex.co.uk/constituency/slough): Mr Tanmanjeet Singh Dhesi (Labour), MP since July 2024. 0.1% of the people here.

As of 18 October 2026. Contains Parliamentary information licensed under the Open Parliament Licence v3.0. Source: UK Parliament, Members API.

## Middle areas in SL4

[Clewer New Town](https://openindex.co.uk/windsor-and-maidenhead/clewer-new-town), [Clewer Village](https://openindex.co.uk/windsor-and-maidenhead/clewer-village), [Dedworth](https://openindex.co.uk/windsor-and-maidenhead/dedworth), [Old Windsor & Wraysbury](https://openindex.co.uk/windsor-and-maidenhead/old-windsor-and-wraysbury), [Spital & Cranbourne Park](https://openindex.co.uk/windsor-and-maidenhead/spital-and-cranbourne-park), [Windsor Town & Eton](https://openindex.co.uk/windsor-and-maidenhead/windsor-town-and-eton)

## Postcode sectors in SL4

[SL4 1 (158 postcodes)](https://openindex.co.uk/postcode/sl4-1), [SL4 2 (216 postcodes)](https://openindex.co.uk/postcode/sl4-2), [SL4 3 (238 postcodes)](https://openindex.co.uk/postcode/sl4-3), [SL4 4 (294 postcodes)](https://openindex.co.uk/postcode/sl4-4), [SL4 5 (260 postcodes)](https://openindex.co.uk/postcode/sl4-5), [SL4 6 (177 postcodes)](https://openindex.co.uk/postcode/sl4-6), [SL4 9 (33 postcodes)](https://openindex.co.uk/postcode/sl4-9)

## Council

[Windsor and Maidenhead](https://openindex.co.uk/windsor-and-maidenhead)

## Towns in SL4

[Old Windsor and Wraysbury](https://openindex.co.uk/town/old-windsor-and-wraysbury), [Windsor](https://openindex.co.uk/town/windsor)

## Postcode districts next to SL4

[GU25](https://openindex.co.uk/postcode/gu25), [RG42](https://openindex.co.uk/postcode/rg42), [SL1](https://openindex.co.uk/postcode/sl1), [SL3](https://openindex.co.uk/postcode/sl3), [SL5](https://openindex.co.uk/postcode/sl5), [SL6](https://openindex.co.uk/postcode/sl6), [TW19](https://openindex.co.uk/postcode/tw19), [TW20](https://openindex.co.uk/postcode/tw20)

## Nearest rail stations

[Windsor and Eton Central (3.1 km from the middle)](https://openindex.co.uk/map/rail-stations?around=-0.6104,51.4833), [Windsor and Eton Riverside (3.5 km from the middle)](https://openindex.co.uk/map/rail-stations?around=-0.6065,51.4856), [Datchet (4.8 km from the middle)](https://openindex.co.uk/map/rail-stations?around=-0.5794,51.4831), [Sunnymeads (5.8 km from the middle)](https://openindex.co.uk/map/rail-stations?around=-0.5594,51.4703)

## More in the SL postcode area

[All SL postcode districts](https://openindex.co.uk/postcode/sl), [Every UK postcode area](https://openindex.co.uk/postcode)

## SL4 in brief

SL4 is a postcode district covering Windsor and Dedworth, in Windsor and Maidenhead.
About 47,013 people lived in SL4 in mid-2024 (worked out by Open Index from ONS small-area estimates); the median price paid for a home was £517,250 in 2025 across 582 sales (HM Land Registry) and police recorded crimes and anti-social behaviour at a rate of 83.8 per 1,000 people in the 12 months to August 2026 (police.uk).
The median price paid for a home in SL4 was £517,250 in 2025.
SL4 had 45,871 usual residents at the census.
About 23% of people in SL4 live in a 1 km square that the radon atlas marks as a radon Affected Area.
In SL4, 83.5% of homes and businesses could get gigabit-capable broadband in January 2026.

## About

- Type: Postcode district
- Code: SL4
- Postcode area: [SL](https://openindex.co.uk/postcode/sl)
- Constituency: [Windsor †](https://openindex.co.uk/constituency/windsor)
- Council: [Windsor and Maidenhead †](https://openindex.co.uk/windsor-and-maidenhead)
- Area: 74.46 km²
- People, mid-2024: 47,013*
- Neighbourhoods: 25
- Output areas: 140

* People: worked out by Open Index from neighbourhood estimates, shared out by where people lived at the census (by area in Northern Ireland). This area's edges do not follow neighbourhood edges, so the figure is close but not exact.
† Best fit: the constituency, council, region and nation this postcode district mostly lies in. Its edges do not follow theirs.

## Next door

[SL6](https://openindex.co.uk/postcode/sl6), [SL5](https://openindex.co.uk/postcode/sl5), [RG42](https://openindex.co.uk/postcode/rg42), [SL1](https://openindex.co.uk/postcode/sl1), [SL3](https://openindex.co.uk/postcode/sl3), [TW20](https://openindex.co.uk/postcode/tw20)

## Latest updates for SL4

- August 2026 house prices published: HM Land Registry and partners · Oct 2026.
- September 2026 rent published: ONS private rents · Oct 2026.
- Dental practices updated: NHS England · Oct 2026.
- Schools updated: Ofsted · Oct 2026.

The same figures as JSON: https://openindex.co.uk/v1/places/SL4

## How to cite

Source: Open Index, openindex.co.uk. Link to this page, https://openindex.co.uk/postcode/sl4, or to one figure with its anchor, https://openindex.co.uk/postcode/sl4#f-house-sales-median-price.

Open Index's own text and the figures it works out are licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source data keeps its publishers' licences, named with each figure. Give each figure's period and source with it.

Snapshot 2026.10.9. The HTML page: https://openindex.co.uk/postcode/sl4