21, Duffryn Street, Mountain Ash occupies a 53 m² plot as recorded by HM Land Registry.

Of the 35 other houses in this postcode, 31 have recorded plot sizes, and this one ranks as the 28th largest.

21, Duffryn Street, Mountain Ash has an Energy Performance Rating (EPC) of D. This is based on the most recent assessment, dated 11 Oct 2017.

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

21, Duffryn Street, Mountain Ash last changed hands on 2nd November 2007, selling for £64,000. The transaction was logged as a freehold house by HM Land Registry.

In total it has sold twice since 1995.

The market for similar properties has risen by 87.5% since November 2007.

• Sold Nov 2007£64,000
• Sold Apr 1998£24,000

Land Registry records and our Estate Agent network show 171 sales of comparable properties within 520 metres of 21, Duffryn Street, Mountain Ash since 2016.

Most recently, 29, Cliff Street, Mountain Ash, CF45 3LE, a freehold house, sold at £120,000 on the 14th November 2025.

Read more about house prices in CF45.

• Sold Nov 2025£120,000 | 3 Bed House29, Cliff Street, Mountain Ash, CF45 3LE29, Cliff Street, Mountain Ash, CF45 3LE
• Sold Sep 2025£112,000 | 3 Bed House31, Napier Street, Mountain Ash, CF45 3HW31, Napier Street, Mountain Ash, CF45 3HW
• Sold Jun 2025£95,000 | 3 Bed House33, Duffryn Street, Mountain Ash, CF45 3NU33, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Nov 2024£100,000 | 3 Bed House21, Dover Street, Mountain Ash, CF45 3HU21, Dover Street, Mountain Ash, CF45 3HU
• Sold Oct 2024£127,500 | 3 Bed House74, Duffryn Street, Mountain Ash, CF45 3HR74, Duffryn Street, Mountain Ash, CF45 3HR
• Sold Apr 2024£81,000 | 3 Bed House28, Duffryn Street, Mountain Ash, CF45 3NU28, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Dec 2023£56,500 | 3 Bed House58A, Duffryn Street, Mountain Ash, CF45 3HR58A, Duffryn Street, Mountain Ash, CF45 3HR
• Sold Sep 2023£75,000 | 3 Bed House5, Duffryn Street, Mountain Ash, CF45 3NU5, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Aug 2023£66,000 | 3 Bed House6, Duffryn Street, Mountain Ash, CF45 3NU6, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Aug 2023£60,000 | 3 Bed House7, Cliff Street, Mountain Ash, CF45 3LE7, Cliff Street, Mountain Ash, CF45 3LE
• Sold Feb 2023£95,000 | 3 Bed House4, Duffryn Street, Mountain Ash, CF45 3NU4, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Feb 2023£95,000 | 3 Bed House14, Cliff Street, Mountain Ash, CF45 3LE14, Cliff Street, Mountain Ash, CF45 3LE
• Sold Aug 2022£72,500 | 3 Bed House30, Duffryn Street, Mountain Ash, CF45 3NU30, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Apr 2022£65,000 | 3 Bed House13, Duffryn Street, Mountain Ash, CF45 3NU13, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Feb 2021£83,000 | 3 Bed House16, Duffryn Street, Mountain Ash, CF45 3NU16, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Jan 2021£42,000 | 3 Bed House12, Oxford Street, Mountain Ash, CF45 3PL12, Oxford Street, Mountain Ash, CF45 3PL
• Sold Apr 2019£70,000 | 3 Bed House24, Duffryn Street, Mountain Ash, CF45 3NU24, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Dec 2018£52,000 | 3 Bed House18, Duffryn Street, Mountain Ash, CF45 3NU18, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Nov 2018£64,000 | 3 Bed House31, Duffryn Street, Mountain Ash, CF45 3NU31, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Jul 2016£45,000 | 3 Bed House7, Duffryn Street, Mountain Ash, CF45 3NU7, Duffryn Street, Mountain Ash, CF45 3NU

Our analysis of the public data ranks 21, Duffryn Street, Mountain Ash as the 45th largest and the 58th most expensive of the 93 addresses on Duffryn Street, Mountain Ash, CF45.

Against the CF45 postcode district average, it is £55k less expensive than the typical property.

• Mountain Ash

  |

  400 m away
• Fernhill

  |

  1.1 km away
• Penrhiwceiber

  |

  2.1 km away

Environment Agency data suggests this area has a Very Low risk of flooding.