According to data from HM Land Registry, 21, Upper William Street, Llanelli sits on a plot of 135 m².

We have plot size data on 14 out of 17 other houses in the postcode and 21, Upper William Street, Llanelli sits on the 9th largest plot.

21, Upper William Street, Llanelli has an Energy Performance Rating (EPC) of C. This is based on the most recent assessment, dated 23 May 2017.

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

According to HM Land Registry, 21, Upper William Street, Llanelli was last sold on 19th June 2015 for £79,500 and was recorded as a freehold house.

The property has had 2 sales since 1995.

Since June 2015, the market for similar properties has risen by 122.9%.

• Sold Jun 2015£79,500
• Sold Aug 2013£51,500

According to the Land Registry and our network of Estate Agents, there have been 136 sales of properties similar to 21, Upper William Street, Llanelli within a radius of 460 metres since 2018.

The most recent example is 4, Wern Road, Llanelli, SA15 1SR, a freehold house which sold for £130,000 on the 29th April 2026.

Read more about house prices in SA15.

• Sold Apr 2026£130,000 | 3 Bed House4, Wern Road, Llanelli, SA15 1SR4, Wern Road, Llanelli, SA15 1SR
• Sold Feb 2026£69,500 | 3 Bed House6, Cae Du Bach, Llanelli, SA15 3AQ6, Cae Du Bach, Llanelli, SA15 3AQ
• Sold Jan 2026£96,600 | 3 Bed House5, Pottery Place, Llanelli, SA15 1ST5, Pottery Place, Llanelli, SA15 1ST
• Sold Aug 2025£96,000 | 3 Bed House7, Als Street, Llanelli, SA15 1SN7, Als Street, Llanelli, SA15 1SN
• Sold Aug 2025£120,000 | 3 Bed House31, Wern Road, Llanelli, SA15 1SP31, Wern Road, Llanelli, SA15 1SP
• Sold Jun 2025£110,000 | 3 Bed House48, Swansea Road, Llanelli, SA15 3YT48, Swansea Road, Llanelli, SA15 3YT
• Sold Dec 2024£87,000 | 3 Bed House21, Swansea Road, Llanelli, SA15 3YT21, Swansea Road, Llanelli, SA15 3YT
• Sold Dec 2024£117,000 | 3 Bed House4, Andrew Street, Llanelli, SA15 3YP4, Andrew Street, Llanelli, SA15 3YP
• Sold Oct 2024£105,000 | 3 Bed House14, Swansea Road, Llanelli, SA15 3YT14, Swansea Road, Llanelli, SA15 3YT
• Sold Aug 2024£112,000 | 3 Bed House3, Marble Hall Road, Llanelli, SA15 1NN3, Marble Hall Road, Llanelli, SA15 1NN
• Sold Jan 2024£72,000 | 3 Bed House94, Swansea Road, Llanelli, SA15 3BJ94, Swansea Road, Llanelli, SA15 3BJ
• Sold Sep 2023£88,000 | 3 Bed House61, Wern Road, Llanelli, SA15 1SP61, Wern Road, Llanelli, SA15 1SP
• Sold Jul 2023£80,000 | 3 Bed House7, Marble Hall Road, Llanelli, SA15 1NN7, Marble Hall Road, Llanelli, SA15 1NN
• Sold Sep 2022£115,000 | 3 Bed House66, Wern Road, Llanelli, SA15 1SR66, Wern Road, Llanelli, SA15 1SR
• Sold Aug 2022£127,000 | 3 Bed House16A, Marble Hall Road, Llanelli, SA15 1NN16A, Marble Hall Road, Llanelli, SA15 1NN
• Sold Mar 2022£80,000 | 3 Bed House23, Wern Road, Llanelli, SA15 1SP23, Wern Road, Llanelli, SA15 1SP
• Sold May 2021£79,000 | 3 Bed House13, Als Street, Llanelli, SA15 1SN13, Als Street, Llanelli, SA15 1SN
• Sold May 2021£100,000 | 3 Bed House15, Als Street, Llanelli, SA15 1SN15, Als Street, Llanelli, SA15 1SN
• Sold Jan 2019£69,000 | 3 Bed House11, Marble Hall Road, Llanelli, SA15 1NN11, Marble Hall Road, Llanelli, SA15 1NN
• Sold Aug 2018£68,750 | 3 Bed House55, Wern Road, Llanelli, SA15 1SP55, Wern Road, Llanelli, SA15 1SP

Upper William Street, Llanelli, SA15 has a total of 17 addresses. According to our analysis of all the public data, 21, Upper William Street, Llanelli is the 10th largest and the 10th most expensive property on the street.

When compared to the postcode district it is £75k less expensive than the average property in SA15.

• Llanelli

  |

  1.0 km away
• Bynea

  |

  4.1 km away
• Llangennech

  |

  5.4 km away

According to data from the Environment Agency, the flood risk in this area is considered to be Very Low.