# Pontprennau and Old St Mellons North east Cardiff. About 12,638 people (mid-2024 estimate) in 8.6 square kilometres. Pontprennau and Old St Mellons had 11,713 usual residents at the census (ONS Census 2021). Ward. Code W05001290. In: [Wales](https://openindex.co.uk/wales) › [Cardiff](https://openindex.co.uk/cardiff) ## Key figures - **Population: 11,713** (2021). Pontprennau and Old St Mellons had 11,713 usual residents at the census (ONS Census 2021). 1,700th most populated of 8,397. 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/cardiff/ward/pontprennau-and-old-st-mellons#f-population - **People in radon Affected Area squares: 100%** (2022). About 100% of people in Pontprennau and Old St Mellons 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/cardiff/ward/pontprennau-and-old-st-mellons#f-radon-affected-share - **Gigabit broadband coverage: 94.9%** (January 2026). In Pontprennau and Old St Mellons, 94.9% 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/cardiff/ward/pontprennau-and-old-st-mellons#f-gigabit-coverage - **Claimant rate: 2.4%** (August 2026). In Pontprennau and Old St Mellons, 2.4% of residents aged 16 to 64 were claiming out-of-work benefits in August 2026 (ONS via Nomis). UK 3.9%. Source: Claimant count (Nomis), August 2026. Published 15 September 2026. https://openindex.co.uk/cardiff/ward/pontprennau-and-old-st-mellons#f-claimant-rate ## On the map - [Radon Affected Area by ward](https://openindex.co.uk/map/radon-affected-areas?place=W05001290) (Worked out by Open Index · 2022): About 100% of people in Pontprennau and Old St Mellons live in a 1 km square that the radon atlas marks as a radon Affected Area. - [Average house price by council](https://openindex.co.uk/map/house-prices?place=W05001290) (UK House Price Index · August 2026): Published for whole councils, so the map colours all of Cardiff. The outline is Pontprennau and Old St Mellons. - [Crime and ASB by ward](https://openindex.co.uk/map/recorded-crime?place=W05001290) (Police recorded crime and outcomes (data.police.uk) · August 2026): Crime and anti-social behaviour for Pontprennau and Old St Mellons. - [Population by ward](https://openindex.co.uk/map/population?place=W05001290) (Census 2021, England and Wales): Pontprennau and Old St Mellons had 11,713 usual residents at the census. ## How Pontprennau and Old St Mellons compares Each ward against every other ward the measure covers. | Measure | Pontprennau and Old St Mellons | Rank | Compared with | | --- | --- | --- | --- | | Population | 11,713 | 14th least populated | 28 wards, Cardiff · 2021 | | People in radon Affected Area squares | 100% | joint most people in radon Affected Areas | 28 wards, Cardiff · 2022 | | Gigabit broadband coverage | 94.9% | 8th lowest | 28 wards, Cardiff · Jan 2026 | | Claimant rate | 2.4% | 11th lowest | 28 wards, Cardiff · Aug 2026 | ## Is Pontprennau and Old St Mellons safe? What police records show In the 12 months to August 2026, police recorded crimes and anti-social behaviour in Pontprennau and Old St Mellons at a rate of 61.2 per 1,000 people. That compares with 112.2 per 1,000 people across Cardiff. Across Wales as a whole, the recorded crime rate was 96.7 per 1,000 people. In August 2026 alone, 111 cases of crime and anti-social behaviour were recorded in Pontprennau and Old St Mellons. In the 12 months to August 2026, the most common types were violence and sexual offences (237), other crime (194) and anti-social behaviour (117). 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. ## Figures for the whole of Cardiff These figures are published for the whole of Cardiff, not for each ward, so they describe all of Cardiff and not Pontprennau and Old St Mellons alone. [See Cardiff](https://openindex.co.uk/cardiff) - **Average house price: £272,443** (August 2026). Cardiff’s average house price was £272,443 in August 2026 (HM Land Registry). Up 2.1% in a year. Source: UK House Price Index, August 2026. Published 21 October 2026. - **Median full-time pay: £36,946** (2025). Full-time workers living in Cardiff earned a median of £36,946 in 2025 (ONS earnings survey). 121st lowest paid of 348. Source: Annual Survey of Hours and Earnings, 2025. Published 23 October 2025. - **House price to pay: 7.4×** (2025). A home in Cardiff costs 7.4 times local full-time pay. Joint 168th least affordable of 348. Source: Worked out by Open Index from the UK House Price Index and the ONS earnings survey. Published 21 October 2026. - **Population estimate: 381,516** (2025). Cardiff’s population was an estimated 381,516 in mid-2025 (ONS population estimates). Down 0.1% in a year. Source: Mid-year population estimates, 2025. Published 1 October 2026. ## Pontprennau and Old St Mellons in brief Pontprennau and Old St Mellons had 11,713 usual residents at the census. About 100% of people in Pontprennau and Old St Mellons live in a 1 km square that the radon atlas marks as a radon Affected Area. In Pontprennau and Old St Mellons, 94.9% of homes and businesses could get gigabit-capable broadband in January 2026. In Pontprennau and Old St Mellons, 2.4% of residents aged 16 to 64 were claiming out-of-work benefits in August 2026. ## About - Type: Ward - Code: W05001290 - Constituency: [Cardiff North †](https://openindex.co.uk/constituency/cardiff-north) - Council: [Cardiff](https://openindex.co.uk/cardiff) - Nation: [Wales](https://openindex.co.uk/wales) - Area: 8.63 km² - People, mid-2024: 12,638* - Neighbourhoods: 7 - Output areas: 38 * 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 this ward mostly lies in. Its edges do not follow it. ## Next door [Lisvane and Thornhill](https://openindex.co.uk/cardiff/ward/lisvane-and-thornhill), [Machen and Rudry](https://openindex.co.uk/caerphilly/ward/machen-and-rudry), [Tredegar Park and Marshfield](https://openindex.co.uk/newport/ward/tredegar-park-and-marshfield), [Llanrumney](https://openindex.co.uk/cardiff/ward/llanrumney), [Trowbridge](https://openindex.co.uk/cardiff/ward/trowbridge), [Pentwyn](https://openindex.co.uk/cardiff/ward/pentwyn) ## Latest updates for Pontprennau and Old St Mellons - 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/W05001290 ## How to cite Source: Open Index, openindex.co.uk. Link to this page, https://openindex.co.uk/cardiff/ward/pontprennau-and-old-st-mellons, or to one figure with its anchor, https://openindex.co.uk/cardiff/ward/pontprennau-and-old-st-mellons#f-population. 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/cardiff/ward/pontprennau-and-old-st-mellons