According to data from HM Land Registry, 18, William Street, Caernarfon sits on a plot of 69 m².

We have plot size data on 38 out of 39 other houses in the postcode and 18, William Street, Caernarfon sits on the 22nd largest plot.

18, William Street, Caernarfon has an Energy Performance Rating (EPC) of D. This is based on the most recent assessment, dated 27 Feb 2026.

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

According to HM Land Registry, 18, William Street, Caernarfon was last sold on 14th November 2014 for £90,000 and was recorded as a freehold house.

The property has only had this single sale since 1995.

Since November 2014, the market for similar properties has risen by 72.3%.

• Sold Nov 2014£90,000

According to the Land Registry and our network of Estate Agents, there have been 74 sales of properties similar to 18, William Street, Caernarfon within a radius of 510 metres since 2009.

The most recent example is 3, New Street, Caernarfon, LL55 2PU, a freehold house which sold for £120,000 on the 22nd December 2025.

Read more about house prices in LL55.

• Sold Dec 2025£120,000 | 3 Bed House3, New Street, Caernarfon, LL55 2PU3, New Street, Caernarfon, LL55 2PU
• Sold Dec 2025£147,500 | 3 Bed House34, Margaret Street, Caernarfon, LL55 1NB34, Margaret Street, Caernarfon, LL55 1NB
• Sold Nov 2025£110,000 | 3 Bed House54, Chapel Street, Caernarfon, LL55 2PS54, Chapel Street, Caernarfon, LL55 2PS
• Sold Mar 2025£95,000 | 3 Bed House3, Cadnant Road, Caernarfon, LL55 1NA3, Cadnant Road, Caernarfon, LL55 1NA
• Sold Nov 2024£150,000 | 3 Bed House12, Holywell Terrace, Caernarfon, LL55 2AP12, Holywell Terrace, Caernarfon, LL55 2AP
• Sold Oct 2024£90,000 | 3 Bed House28, William Street, Caernarfon, LL55 1ND28, William Street, Caernarfon, LL55 1ND
• Sold Oct 2024£88,000 | 3 Bed House50, Chapel Street, Caernarfon, LL55 2PS50, Chapel Street, Caernarfon, LL55 2PS
• Sold Jul 2024£111,000 | 3 Bed House37, William Street, Caernarfon, LL55 1ND37, William Street, Caernarfon, LL55 1ND
• Sold Jun 2024£90,000 | 3 Bed House9, Assheton Terrace, Caernarfon, LL55 2LD9, Assheton Terrace, Caernarfon, LL55 2LD
• Sold Dec 2023£60,000 | 3 Bed House58, Chapel Street, Caernarfon, LL55 2PS58, Chapel Street, Caernarfon, LL55 2PS
• Sold Aug 2023£131,750 | 3 Bed House40, Chapel Street, Caernarfon, LL55 2PS40, Chapel Street, Caernarfon, LL55 2PS
• Sold Nov 2022£160,000 | 3 Bed House3, Tithebarn Street, Caernarfon, LL55 2RF3, Tithebarn Street, Caernarfon, LL55 2RF
• Sold Aug 2022£125,000 | 3 Bed House15, New Street, Caernarfon, LL55 2PU15, New Street, Caernarfon, LL55 2PU
• Sold Aug 2022£105,000 | 3 Bed House52, Chapel Street, Caernarfon, LL55 2PS52, Chapel Street, Caernarfon, LL55 2PS
• Sold Jun 2022£135,000 | 3 Bed House23, New Street, Caernarfon, LL55 2PU23, New Street, Caernarfon, LL55 2PU
• Sold May 2022£107,500 | 3 Bed House20, William Street, Caernarfon, LL55 1ND20, William Street, Caernarfon, LL55 1ND
• Sold Jan 2021£110,000 | 3 Bed House11, William Street, Caernarfon, LL55 1ND11, William Street, Caernarfon, LL55 1ND
• Sold Jun 2020£95,000 | 3 Bed House14, William Street, Caernarfon, LL55 1ND14, William Street, Caernarfon, LL55 1ND
• Sold Jan 2013£88,000 | 3 Bed House17, William Street, Caernarfon, LL55 1ND17, William Street, Caernarfon, LL55 1ND
• Sold Dec 2009£86,500 | 3 Bed House10, William Street, Caernarfon, LL55 1ND10, William Street, Caernarfon, LL55 1ND

William Street, Caernarfon, LL55 has a total of 39 addresses. According to our analysis of all the public data, 18, William Street, Caernarfon is the 5th largest and the 7th most expensive property on the street.

When compared to the postcode district it is £99k less expensive than the average property in LL55.

• Llanfairpwll

  |

  9.8 km away
• Bodorgan

  |

  12.2 km away
• Bangor (Gwynedd)

  |

  12.7 km away

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