Flat 3, 18, Belsize Square has an Energy Performance Rating (EPC) of C. This is based on the most recent assessment, dated 06 Feb 2026.

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

According to HM Land Registry, Flat 3, 18, Belsize Square was last sold on 23rd January 2015 for £1,960,000 and was recorded as a leasehold flat.

The property has had 3 sales since 1995.

Since January 2015, the market for similar properties has dropped by 19.7%.

• Sold Jan 2015£1,960,000
• Sold Jun 2006£625,000
• Sold Aug 1996£187,000

According to the Land Registry and our network of Estate Agents, there have been 46 sales of properties similar to Flat 3, 18, Belsize Square within a radius of 270 metres since 2012.

The most recent example is Flat 3, 29, Belsize Park Gardens, London, NW3 4JH, a leasehold flat which sold for £1,500,000 on the 3rd October 2025.

Read more about house prices in NW3.

• Sold Oct 2025£1,500,000 | 3 Bed FlatFlat 3, 29, Belsize Park Gardens, London, NW3 4JHFlat 3, 29, Belsize Park Gardens, London, NW3 4JH
• Sold Jul 2025£2,000,000 | 3 Bed Flat10A, Belsize Park, London, NW3 4ES10A, Belsize Park, London, NW3 4ES
• Sold Jun 2025£1,695,000 | 3 Bed FlatFlat 5, 32, Eton Avenue, London, NW3 3HLFlat 5, 32, Eton Avenue, London, NW3 3HL
• Sold Nov 2024£1,779,500 | 3 Bed Flat37C , Belsize Park Gardens, London, NW3 4JJ37C , Belsize Park Gardens, London, NW3 4JJ
• Sold May 2024£1,525,000 | 3 Bed FlatFlat 4, 36, Eton Avenue, London, NW3 3HLFlat 4, 36, Eton Avenue, London, NW3 3HL
• Sold Dec 2023£1,850,000 | 3 Bed FlatFlat 2, 8, Belsize Park Gardens, London, NW3 4LDFlat 2, 8, Belsize Park Gardens, London, NW3 4LD
• Sold Aug 2023£1,850,000 | 3 Bed FlatFlat 1, 8, Belsize Park Gardens, London, NW3 4LDFlat 1, 8, Belsize Park Gardens, London, NW3 4LD
• Sold Sep 2022£1,706,000 | 3 Bed FlatFlat 2, 35, Eton Avenue, London, NW3 3EPFlat 2, 35, Eton Avenue, London, NW3 3EP
• Sold Feb 2022£1,625,000 | 3 Bed Flat15A, Belsize Square, London, NW3 4HT15A, Belsize Square, London, NW3 4HT
• Sold Apr 2021£1,675,000 | 3 Bed FlatFlat 2, 16, Belsize Park Gardens, London, NW3 4LDFlat 2, 16, Belsize Park Gardens, London, NW3 4LD
• Sold Apr 2021£1,475,000 | 4 Bed Flat26B , Belsize Park Gardens, London, NW3 4LH26B , Belsize Park Gardens, London, NW3 4LH
• Sold Mar 2021£2,025,000 | 3 Bed FlatFlat 2, 28, Eton Avenue, London, NW3 3HLFlat 2, 28, Eton Avenue, London, NW3 3HL
• Sold Sep 2020£1,885,000 | 3 Bed FlatFlat 2, 35, Belsize Park Gardens, London, NW3 4JJFlat 2, 35, Belsize Park Gardens, London, NW3 4JJ
• Sold Aug 2020£1,585,000 | 3 Bed Flat14A, Belsize Square, London, NW3 4HT14A, Belsize Square, London, NW3 4HT
• Sold Oct 2019£1,876,000 | 3 Bed FlatFlat 1, 13, Belsize Park Gardens, London, NW3 4JGFlat 1, 13, Belsize Park Gardens, London, NW3 4JG
• Sold Jul 2018£1,715,000 | 4 Bed Flat18A, Belsize Park, London, NW3 4DU18A, Belsize Park, London, NW3 4DU
• Sold Sep 2017£1,485,000 | 4 Bed FlatFlat 7, 25, Belsize Park, London, NW3 4DUFlat 7, 25, Belsize Park, London, NW3 4DU
• Sold Mar 2016£1,835,500 | 4 Bed Flat12C , Belsize Square, London, NW3 4HT12C , Belsize Square, London, NW3 4HT
• Sold Dec 2012£1,780,000 | 4 Bed FlatFlat 41, Eton Court, Eton Avenue, London, NW3 3HJFlat 41, Eton Court, Eton Avenue, London, NW3 3HJ
• Sold Aug 2012£1,560,000 | 3 Bed Flat21A, Buckland Crescent, London, NW3 5DH21A, Buckland Crescent, London, NW3 5DH

Our network of Estate Agents reports 2 lets within 270 metres of Flat 3, 18, Belsize Square over the last 2 years.

Most recently, 3B , Lancaster Drive, London, NW3 4EY, a leasehold flat, was let by Fine Living in February 2025.

• 
  Let agreed Feb 2025£ Undisclosed | 2 Bed Flat3B , Lancaster Drive, London, NW3 4EY3B , Lancaster Drive, London, NW3 4EY
• 
  Let agreed Mar 2024£ Undisclosed | 1 Bed Flat3A , Lancaster Drive, London, NW3 4EY3A , Lancaster Drive, London, NW3 4EY

•Nearby is defined as the radius comprising the nearest 2,000 addresses.

Belsize Square, London, NW3 has a total of 264 addresses. According to our analysis of all the public data, Flat 3, 18, Belsize Square is the 30th largest and the 26th most expensive property on the street.

When compared to the postcode district it is £312k more expensive than the average property in NW3.

• Holy Trinity CofE Primary School, NW3

  500 m away
• Rosary Catholic Primary School

  600 m away
• St Paul's Church of England Primary School

  800 m away

• The UCL Academy

  600 m away
• Harris Academy St John's Wood

  1.1 km away
• Haverstock School

  1.2 km away

• Swiss Cottage

  |

  500 m away
• Belsize Park

  |

  600 m away
• Finchley Road

  |

  600 m away

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