HM Land Registry records the plot of land for 21, Thomas Street, Mountain Ash as measuring 145 m².

That makes it the 13th largest plot in the postcode, where 24 of the 41 other houses have recorded plot data.

21, Thomas Street, Mountain Ash has an Energy Performance Rating (EPC) of D. This is based on the most recent assessment, dated 03 Sep 2020.

The property is connected to mains gas and has fully double glazed windows. It is heated using a boiler and radiators (mains gas).

The most recent sale of 21, Thomas Street, Mountain Ash completed on 29th April 2022 at £125,000 and was recorded by HM Land Registry as a leasehold house.

Since 1995 the property has sold twice.

Values of comparable properties have risen by 33.8% over the period since April 2022.

• Sold Apr 2022£125,000
• Sold Feb 2000£24,000

Since 2019 198 properties similar to 21, Thomas Street, Mountain Ash have sold within a radius of 610 metres, per the Land Registry and our network of Estate Agents.

The latest, on the 20th February 2026, was 12, Thomas Street, Mountain Ash, CF45 3BU, a freehold house which sold for £145,000.

Read more about house prices in CF45.

• Sold Feb 2026£145,000 | 3 Bed House12, Thomas Street, Mountain Ash, CF45 3BU12, Thomas Street, Mountain Ash, CF45 3BU
• Sold Nov 2025£122,000 | 3 Bed House13, Hughes Street, Mountain Ash, CF45 3UG13, Hughes Street, Mountain Ash, CF45 3UG
• Sold Oct 2025£112,000 | 3 Bed House32, Oakland Street, Mountain Ash, CF45 3AL32, Oakland Street, Mountain Ash, CF45 3AL
• Sold Sep 2025£125,000 | 3 Bed House26, Albany Street, Mountain Ash, CF45 3BE26, Albany Street, Mountain Ash, CF45 3BE
• Sold Apr 2025£118,000 | 3 Bed House11, Albany Street, Mountain Ash, CF45 3BE11, Albany Street, Mountain Ash, CF45 3BE
• Sold Feb 2025£99,950 | 3 Bed House7, Albany Street, Mountain Ash, CF45 3BE7, Albany Street, Mountain Ash, CF45 3BE
• Sold Nov 2024£120,000 | 3 Bed House22, Albany Street, Mountain Ash, CF45 3BE22, Albany Street, Mountain Ash, CF45 3BE
• Sold Aug 2024£137,500 | 3 Bed House27, Oakland Street, Mountain Ash, CF45 3AL27, Oakland Street, Mountain Ash, CF45 3AL
• Sold Aug 2024£112,000 | 3 Bed House17, Consort Street, Mountain Ash, CF45 3AY17, Consort Street, Mountain Ash, CF45 3AY
• Sold Sep 2023£92,500 | 3 Bed House5, Albany Street, Mountain Ash, CF45 3BE5, Albany Street, Mountain Ash, CF45 3BE
• Sold Jun 2023£68,000 | 3 Bed House8, Albany Street, Mountain Ash, CF45 3BE8, Albany Street, Mountain Ash, CF45 3BE
• Sold May 2023£96,950 | 3 Bed House22, Oakland Street, Mountain Ash, CF45 3AL22, Oakland Street, Mountain Ash, CF45 3AL
• Sold Jul 2022£93,000 | 3 Bed House18, Oakland Street, Mountain Ash, CF45 3AL18, Oakland Street, Mountain Ash, CF45 3AL
• Sold May 2022£75,000 | 3 Bed House4, Thomas Street, Mountain Ash, CF45 3BU4, Thomas Street, Mountain Ash, CF45 3BU
• Sold Jan 2022£85,000 | 3 Bed House39, Thomas Street, Mountain Ash, CF45 3BU39, Thomas Street, Mountain Ash, CF45 3BU
• Sold Jan 2022£135,000 | 3 Bed House29, Oakland Street, Mountain Ash, CF45 3AL29, Oakland Street, Mountain Ash, CF45 3AL
• Sold Nov 2021£122,500 | 3 Bed House15, Hughes Street, Mountain Ash, CF45 3UG15, Hughes Street, Mountain Ash, CF45 3UG
• Sold Aug 2020£90,000 | 3 Bed House39, Oakland Street, Mountain Ash, CF45 3AL39, Oakland Street, Mountain Ash, CF45 3AL
• Sold Dec 2019£96,000 | 3 Bed House16, Thomas Street, Mountain Ash, CF45 3BU16, Thomas Street, Mountain Ash, CF45 3BU
• Sold May 2019£55,000 | 3 Bed House36, Thomas Street, Mountain Ash, CF45 3BU36, Thomas Street, Mountain Ash, CF45 3BU

Of the 73 addresses on Thomas Street, Mountain Ash, CF45, 21, Thomas Street, Mountain Ash comes out as the 40th largest and the 27th most expensive in our analysis of the public data.

It is also £27k less expensive than the average property across the CF45 district.

• Mountain Ash

  |

  800 m away
• Penrhiwceiber

  |

  1.0 km away
• Fernhill

  |

  2.1 km away

The flood risk here is rated Very Low, based on Environment Agency data.