HM Land Registry records the plot of land for 18, Duffryn Street, Mountain Ash as measuring 85 m².

That makes it the 23rd largest plot in the postcode, where 31 of the 35 other houses have recorded plot data.

18, Duffryn Street, Mountain Ash has an Energy Performance Rating (EPC) of D. This is based on the most recent assessment, dated 24 May 2018.

The property is connected to mains gas and has mostly double glazing. It is heated using a boiler and radiators (mains gas).

The most recent sale of 18, Duffryn Street, Mountain Ash completed on 6th December 2018 at £52,000 and was recorded by HM Land Registry as a freehold house.

Since 1995 this is the property's only sale.

Values of comparable properties have risen by 91.4% over the period since December 2018.

• Sold Dec 2018£52,000

Since 2016 96 properties similar to 18, Duffryn Street, Mountain Ash have sold within a radius of 530 metres, per the Land Registry and our network of Estate Agents.

The latest, on the 14th November 2025, was 29, Cliff Street, Mountain Ash, CF45 3LE, a freehold house which sold for £120,000.

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 Jun 2025£95,000 | 3 Bed House33, Duffryn Street, Mountain Ash, CF45 3NU33, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Dec 2024£115,000 | 3 Bed House19, Pryce Street, Mountain Ash, CF45 3NT19, Pryce Street, Mountain Ash, CF45 3NT
• Sold Dec 2024£68,000 | 3 Bed House5, Fountain Street, Mountain Ash, CF45 3PA5, Fountain Street, Mountain Ash, CF45 3PA
• Sold Jul 2024£72,000 | 3 Bed House20, Stream Street, Mountain Ash, CF45 3LL20, Stream Street, Mountain Ash, CF45 3LL
• Sold Jun 2024£75,000 | 3 Bed House16, Stream Street, Mountain Ash, CF45 3LL16, Stream Street, Mountain Ash, CF45 3LL
• Sold Apr 2024£81,000 | 3 Bed House28, Duffryn Street, Mountain Ash, CF45 3NU28, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Feb 2024£89,000 | 3 Bed House24, Napier Street, Mountain Ash, CF45 3HW24, Napier Street, Mountain Ash, CF45 3HW
• 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 Feb 2023£95,000 | 3 Bed House4, Duffryn Street, Mountain Ash, CF45 3NU4, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Aug 2022£72,500 | 3 Bed House30, Duffryn Street, Mountain Ash, CF45 3NU30, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Apr 2022£60,000 | 3 Bed House2, Commercial Street, Mountain Ash, CF45 3PS2, Commercial Street, Mountain Ash, CF45 3PS
• Sold Mar 2022£55,000 | 3 Bed House1A, Cliff Street, Mountain Ash, CF45 3LE1A, Cliff Street, Mountain Ash, CF45 3LE
• Sold Jun 2021£78,000 | 3 Bed House26, Duffryn Street, Mountain Ash, CF45 3NU26, 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 Nov 2019£62,000 | 3 Bed House32, Duffryn Street, Mountain Ash, CF45 3NU32, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Sep 2018£36,000 | 3 Bed House21, Duffryn Street, Mountain Ash, CF45 3NU21, Duffryn Street, Mountain Ash, CF45 3NU
• Sold Aug 2016£47,500 | 3 Bed House12, Duffryn Street, Mountain Ash, CF45 3NU12, Duffryn Street, Mountain Ash, CF45 3NU

Of the 93 addresses on Duffryn Street, Mountain Ash, CF45, 18, Duffryn Street, Mountain Ash comes out as the 68th largest and the 72nd most expensive in our analysis of the public data.

It is also £61k less expensive than the average property across the CF45 district.

• Mountain Ash

  |

  400 m away
• Fernhill

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  1.1 km away
• Penrhiwceiber

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  2.1 km away

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