Flat 4, 9, Belsize Square has an Energy Performance Rating (EPC) of C. This is based on the most recent assessment, dated 11 Aug 2020.

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

Flat 4, 9, Belsize Square last changed hands on 18th October 2010, selling for £424,500. The transaction was logged as a leasehold flat by HM Land Registry.

In total it has sold twice since 1995.

The market for similar properties has risen by 23.6% since October 2010.

• Sold Oct 2010£424,500
• Sold Jul 1999£155,000

Land Registry records and our Estate Agent network show 21 sales of comparable properties within 270 metres of Flat 4, 9, Belsize Square since 2007.

Most recently, Flat 2, 22, Belsize Avenue, London, NW3 4AU, a leasehold flat, sold at £545,000 on the 5th December 2025.

Read more about house prices in NW3.

• Sold Dec 2025£545,000 | 1 Bed FlatFlat 2, 22, Belsize Avenue, London, NW3 4AUFlat 2, 22, Belsize Avenue, London, NW3 4AU
• Sold Jul 2023£525,000 | 1 Bed FlatFlat 5, 5, Belsize Avenue, London, NW3 4BLFlat 5, 5, Belsize Avenue, London, NW3 4BL
• Sold Sep 2022£615,000 | 1 Bed FlatFlat 3, Claridge House 13, Belsize Park, London, NW3 4ESFlat 3, Claridge House 13, Belsize Park, London, NW3 4ES
• Sold Sep 2022£455,000 | 1 Bed FlatFlat 4, 47, Belsize Park, London, NW3 4EEFlat 4, 47, Belsize Park, London, NW3 4EE
• Sold Mar 2022£519,000 | 1 Bed Flat4E , Belsize Square, London, NW3 4HT4E , Belsize Square, London, NW3 4HT
• Sold Jun 2021£535,000 | 1 Bed FlatFlat 7, 5, Belsize Avenue, London, NW3 4BLFlat 7, 5, Belsize Avenue, London, NW3 4BL
• Sold Jan 2021£525,000 | 1 Bed Flat41D, Belsize Square, London, NW3 4HN41D, Belsize Square, London, NW3 4HN
• Sold Jan 2021£560,000 | 1 Bed FlatFlat 7, 31, Adamson Road, London, NW3 3HTFlat 7, 31, Adamson Road, London, NW3 3HT
• Sold Dec 2019£490,000 | 1 Bed FlatFlat 6, 5, Belsize Avenue, London, NW3 4BLFlat 6, 5, Belsize Avenue, London, NW3 4BL
• Sold Mar 2016£602,500 | 1 Bed Flat16G , Belsize Square, London, NW3 4HT16G , Belsize Square, London, NW3 4HT
• Sold May 2014£435,000 | 1 Bed FlatFlat 5, 4, Lancaster Grove, London, NW3 4NXFlat 5, 4, Lancaster Grove, London, NW3 4NX
• Sold Mar 2014£525,000 | 1 Bed FlatFlat 1, 16, Belsize Avenue, London, NW3 4AUFlat 1, 16, Belsize Avenue, London, NW3 4AU
• Sold Dec 2013£625,000 | 1 Bed FlatFlat E, 10, Belsize Square, London, NW3 4HTFlat E, 10, Belsize Square, London, NW3 4HT
• Sold Jun 2013£360,000 | 1 Bed FlatFlat 4, 5, Belsize Avenue, London, NW3 4BLFlat 4, 5, Belsize Avenue, London, NW3 4BL
• Sold Mar 2012£357,500 | 1 Bed FlatFlat 5, 38, Belsize Square, London, NW3 4HLFlat 5, 38, Belsize Square, London, NW3 4HL
• Sold Dec 2011£433,300 | 1 Bed FlatFlat 3, 20, Belsize Park Gardens, London, NW3 4LHFlat 3, 20, Belsize Park Gardens, London, NW3 4LH
• Sold Oct 2010£350,000 | 1 Bed FlatFlat 1, 4, Belsize Park Gardens, London, NW3 4LDFlat 1, 4, Belsize Park Gardens, London, NW3 4LD
• Sold Oct 2008£320,000 | 1 Bed Flat79B , Belsize Lane, London, NW3 5AU79B , Belsize Lane, London, NW3 5AU
• Sold Mar 2008£308,000 | 1 Bed FlatFlat 8, 17, Crossfield Road, London, NW3 4NTFlat 8, 17, Crossfield Road, London, NW3 4NT
• Sold Oct 2007£317,500 | 1 Bed FlatFlat C, 3, Belsize Square, London, NW3 4HTFlat C, 3, Belsize Square, London, NW3 4HT

Agents in our network have reported 2 lettings within 270 metres of Flat 4, 9, Belsize Square across the last 2 years.

The newest of these is 3B , Lancaster Drive, London, NW3 4EY, a leasehold flat 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.

Our analysis of the public data ranks Flat 4, 9, Belsize Square as the 241st largest and the 220th most expensive of the 264 addresses on Belsize Square, London, NW3.

Against the NW3 postcode district average, it is £760k less expensive than the typical property.

• 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

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