# SL9

Postcode district covering Chalfont St Peter, Gerrards Cross and Chalfont Common, in Buckinghamshire.

SL9 is a postcode district covering Chalfont St Peter, Gerrards Cross and Chalfont Common, in Buckinghamshire. Median sale price £867,500 in 2025.

Postcode district. Code SL9. 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 SL9 postcode. [How census figures are added up](https://openindex.co.uk/sources/population)

## Key figures

- **Median sale price: £867,500** (2025). The median price paid for a home in SL9 was £867,500 in 2025. 33rd 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/sl9#f-house-sales-median-price
- **Population: 22,256** (2021). SL9 had 22,256 usual residents at the census (ONS Census 2021). 1,326th 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/sl9#f-population
- **People in radon Affected Area squares: 95%** (2022). About 95% of people in SL9 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/sl9#f-radon-affected-share
- **Gigabit broadband coverage: 92.1%** (January 2026). In SL9, 92.1% 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/sl9#f-gigabit-coverage

## On the map

- [Radon Affected Area by postcode district](https://openindex.co.uk/map/radon-affected-areas?place=SL9) (Worked out by Open Index · 2022): About 95% of people in SL9 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=SL9) (Worked out by Open Index · 2025): 324 homes were sold in SL9 in 2025.
- [Crime and ASB by postcode district](https://openindex.co.uk/map/recorded-crime?place=SL9) (Police recorded crime and outcomes (data.police.uk) · August 2026): Crime and anti-social behaviour for SL9.
- [Population by postcode district](https://openindex.co.uk/map/population?place=SL9) (Census 2021, England and Wales): SL9 had 22,256 usual residents at the census.

## How SL9 compares

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

| Measure | SL9 | Rank | Compared with |
| --- | --- | --- | --- |
| Median sale price | £867,500 | most expensive | 10 postcode districts, SL · 2025 |
| Population | 22,256 | 6th least populated | 12 postcode districts, SL · 2021 |
| People in radon Affected Area squares | 95% | 4th most people in radon Affected Areas | 12 postcode districts, SL · 2022 |
| Gigabit broadband coverage | 92.1% | 4th highest | 12 postcode districts, SL · Jan 2026 |

## Is SL9 safe? What police records show

In the 12 months to August 2026, police recorded crimes and anti-social behaviour in SL9 at a rate of 46.5 per 1,000 people.
That compares with 77.9 per 1,000 people across the SL postcode area.
In August 2026 alone, 93 cases of crime and anti-social behaviour were recorded in SL9.
In the 12 months to August 2026, the most common types were violence and sexual offences (347), other crime (218) and anti-social behaviour (121).
A year earlier, the recorded crime rate in SL9 was 47.0 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 SL9, neighbourhood by neighbourhood

- Deprivation is ranked by neighbourhood, so SL9 has no single figure. Of its 13 neighbourhoods with a rank:
- Decile 8: 3 neighbourhoods
- Decile 9: 4 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 SL9

| Area | People (census) | Recorded crime per 1,000 | Deprivation decile | Gigabit broadband |
| --- | --- | --- | --- | --- |
| [Buckinghamshire 050A](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017754) | 1,533 | 44.9 per 1,000 | 9 | 94.1% |
| [Buckinghamshire 050B](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017755) | 1,990 | 74.7 per 1,000 | 9 | 91.0% |
| [Buckinghamshire 050C](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017756) | 1,497 | 29.5 per 1,000 | 10 | 94.5% |
| [Buckinghamshire 050D](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017757) | 1,184 | 63.9 per 1,000 | 10 | 82.9% |
| [Buckinghamshire 050E](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017758) | 1,358 | 11.6 per 1,000 | 9 | 76.2% |
| [Buckinghamshire 054A](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017751) | 2,141 | 26.4 per 1,000 | 10 | 85.8% |
| [Buckinghamshire 054B](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017753) | 1,300 | 48.9 per 1,000 | 8 | 98.4% |
| [Buckinghamshire 054C](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017767) | 2,379 | 47.4 per 1,000 | 9 | 92.1% |
| [Buckinghamshire 058A](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017818) | 2,086 | 52.0 per 1,000 | 8 | 97.1% |
| [Buckinghamshire 058B](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017819) | 1,670 | 31.8 per 1,000 | 10 | 98.0% |
| [Buckinghamshire 058C](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017820) | 1,782 | 124.9 per 1,000 | 10 | 98.2% |
| [Buckinghamshire 058D](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017821) | 1,612 | 23.5 per 1,000 | 8 | 89.3% |
| [Buckinghamshire 058E](https://openindex.co.uk/buckinghamshire/neighbourhood/e01017822) | 2,111 | 20.0 per 1,000 | 10 | 96.0% |

## Your MP

- [Chesham and Amersham](https://openindex.co.uk/constituency/chesham-and-amersham): Sarah Green (Liberal Democrat), MP since July 2024. 97% of the people here.
- [Beaconsfield](https://openindex.co.uk/constituency/beaconsfield): Joy Morrissey (Conservative), MP since July 2024. 3.0% of the people here.
- [South West Hertfordshire](https://openindex.co.uk/constituency/south-west-hertfordshire): Mr Gagan Mohindra (Conservative), MP since July 2024. 0.3% 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 SL9

[Chalfont Common & St Peter East](https://openindex.co.uk/buckinghamshire/chalfont-common-and-st-peter-east), [Chalfont St Peter West](https://openindex.co.uk/buckinghamshire/chalfont-st-peter-west), [Gerrards Cross](https://openindex.co.uk/buckinghamshire/gerrards-cross)

## Postcode sectors in SL9

[SL9 0 (215 postcodes)](https://openindex.co.uk/postcode/sl9-0), [SL9 1 (16 postcodes)](https://openindex.co.uk/postcode/sl9-1), [SL9 7 (179 postcodes)](https://openindex.co.uk/postcode/sl9-7), [SL9 8 (235 postcodes)](https://openindex.co.uk/postcode/sl9-8), [SL9 9 (227 postcodes)](https://openindex.co.uk/postcode/sl9-9)

## Council

[Buckinghamshire](https://openindex.co.uk/buckinghamshire)

## Towns in SL9

[Chalfont St Peter](https://openindex.co.uk/town/chalfont-st-peter), [Gerrards Cross](https://openindex.co.uk/town/gerrards-cross)

## Postcode districts next to SL9

[HP8](https://openindex.co.uk/postcode/hp8), [HP9](https://openindex.co.uk/postcode/hp9), [SL2](https://openindex.co.uk/postcode/sl2), [SL3](https://openindex.co.uk/postcode/sl3), [UB9](https://openindex.co.uk/postcode/ub9), [WD3](https://openindex.co.uk/postcode/wd3)

## Nearest rail stations

[Gerrards Cross (700 m from the middle)](https://openindex.co.uk/map/rail-stations?around=-0.5553,51.5890), [Denham Golf Club (3.4 km from the middle)](https://openindex.co.uk/map/rail-stations?around=-0.5178,51.5806), [Seer Green and Jordans (3.6 km from the middle)](https://openindex.co.uk/map/rail-stations?around=-0.6078,51.6098), [Denham (4.8 km from the middle)](https://openindex.co.uk/map/rail-stations?around=-0.4974,51.5788)

## 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)

## SL9 in brief

SL9 is a postcode district covering Chalfont St Peter, Gerrards Cross and Chalfont Common, in Buckinghamshire.
About 23,047 people lived in SL9 in mid-2024 (worked out by Open Index from ONS small-area estimates); the median price paid for a home was £867,500 in 2025 across 324 sales (HM Land Registry) and police recorded crimes and anti-social behaviour at a rate of 46.5 per 1,000 people in the 12 months to August 2026 (police.uk).
The median price paid for a home in SL9 was £867,500 in 2025.
SL9 had 22,256 usual residents at the census.
About 95% of people in SL9 live in a 1 km square that the radon atlas marks as a radon Affected Area.
In SL9, 92.1% of homes and businesses could get gigabit-capable broadband in January 2026.

## About

- Type: Postcode district
- Code: SL9
- Postcode area: [SL](https://openindex.co.uk/postcode/sl)
- Constituency: [Chesham and Amersham †](https://openindex.co.uk/constituency/chesham-and-amersham)
- Council: [Buckinghamshire †](https://openindex.co.uk/buckinghamshire)
- Area: 27.35 km²
- People, mid-2024: 23,047*
- Neighbourhoods: 13
- Output areas: 62

* 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

[HP9](https://openindex.co.uk/postcode/hp9), [UB9](https://openindex.co.uk/postcode/ub9), [WD3](https://openindex.co.uk/postcode/wd3), [HP8](https://openindex.co.uk/postcode/hp8), [SL3](https://openindex.co.uk/postcode/sl3), [SL2](https://openindex.co.uk/postcode/sl2)

## Latest updates for SL9

- 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/SL9

## How to cite

Source: Open Index, openindex.co.uk. Link to this page, https://openindex.co.uk/postcode/sl9, or to one figure with its anchor, https://openindex.co.uk/postcode/sl9#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/sl9