CF3, Cardiff: St Mellons, Trowbridge and Rumney

This page brings together the official data on CF3, a postcode district mostly in Cardiff, with part in Newport, so you can see what homes cost and what the area is like in one place.

There are around 17,700 homes in CF3, in places including St Mellons, Trowbridge, Rumney and Llanedeyrn Village. Of the homes that sold, semi-detached houses were the most common, at about two in five. Terraced houses come next, at about three in ten. About 17% of sales were new builds.

In the five years to August 2026, homes in CF3 sold for about £250,000 on average, up 29% on the five years before. Across Cardiff, where most of CF3 is, homes sold for about £262,000 over the same five years, so prices here are lower. Most of CF3's postcodes are outside mapped flood risk areas.

All figures come from official sources, listed at the bottom of this page.

Of the homes sold in the five years to August 2026, 39% were semi-detached houses, 29% were terraced houses, 22% were detached houses and 9% were flats. 10% were leasehold and 17% were new builds (520 sales).

The latest EPC rating of each of the 17,733 homes on record, from the EPC register. Most are rated C and D, and 15% have no EPC on record.

• A2% (356)
• B15% (2,583)
• C38% (6,822)
• D25% (4,398)
• E5% (829)
• F1% (109)
• Gunder 1% (28)
• None15% (2,608)

18 state schools have a CF3 postcode, and 17 more are within a mile of one of its postcodes. Being near a school is not the same as being in its catchment: check admissions with the council.

Estyn, the inspectorate for schools in Wales, stopped giving schools an overall grade from spring 2022, so there is no single rating to show. Each school's inspection reports are on estyn.gov.wales.

We checked the centre of each of CF3's 922 postcodes against the flood risk maps from Natural Resources Wales. 741 sit outside every mapped area, and 181 are in one: 1 at medium risk and 180 at low risk. The centre of a postcode is not each home in it, so check an exact address on NRW's flood risk map.

• Medium risk from the sea: Between a 1 in 200 (0.5%) and a 1 in 30 (3.3%) chance of flooding each year.
• Low risk from rivers or surface water and small watercourses: Between a 1 in 1,000 (0.1%) and a 1 in 100 (1%) chance of flooding each year.
• Low risk from the sea: Between a 1 in 1,000 (0.1%) and a 1 in 200 (0.5%) chance of flooding each year.

The sentence above counts each postcode once, at its highest risk. The table counts it under each source, so a postcode at risk from more than one source appears more than once.

NRW's map takes into account the effect of flood defences where it has information on them. Defences reduce the chance of flooding but do not completely stop it, as they can be overtopped or fail.

142 postcode centres are in areas NRW is reviewing, so the risk there may change.

Contains Natural Resources Wales information © Natural Resources Wales and database right. All rights reserved. Some features of this information are based on digital spatial data licensed from the UK Centre for Ecology & Hydrology © UKCEH. Defra, Met Office and DARD Rivers Agency © Crown copyright. © Cranfield University. © James Hutton Institute. Contains OS data © Crown copyright and database right.

CF3 has 863 postcodes with homes, in 7 sectors. Search above by postcode or street, or open a sector below and choose a postcode to check a home there. Each postcode is shown with its main street.