12C, Belsize Square has an Energy Performance Rating (EPC) of D. This is based on the most recent assessment, dated 23 Jan 2019.

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

The most recent sale of 12C, Belsize Square completed on 31st March 2016 at £1,835,500 and was recorded by HM Land Registry as a leasehold flat.

Since 1995 the property has sold 3 times.

Values of comparable properties have risen by 8.2% over the period since March 2016.

• Sold Mar 2016£1,835,500
• Sold Jul 2012£825,000
• Sold Jul 2006£570,000

Since 2010 26 properties similar to 12C, Belsize Square have sold within a radius of 280 metres, per the Land Registry and our network of Estate Agents.

The latest, on the 5th September 2025, was 37A, Belsize Park Gardens, London, NW3 4JJ, a leasehold flat which sold for £2,180,000.

Read more about house prices in NW3.

• Sold Sep 2025£2,180,000 | 4 Bed Flat37A, Belsize Park Gardens, London, NW3 4JJ37A, Belsize Park Gardens, London, NW3 4JJ
• 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 Oct 2024£2,100,000 | 3 Bed Flat79A, Belsize Lane, London, NW3 5AU79A, Belsize Lane, London, NW3 5AU
• 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 Nov 2021£4,060,118 | 4 Bed FlatFlat 1, Belsize Studios, Glenilla Road, London, NW3 4ATFlat 1, Belsize Studios, Glenilla Road, London, NW3 4AT
• 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 Feb 2021£1,800,000 | 3 Bed FlatFlat 4, Gabrielle Court 1-3, Lancaster Grove, London, NW3 4EUFlat 4, Gabrielle Court 1-3, Lancaster Grove, London, NW3 4EU
• 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 Mar 2016£1,687,500 | 4 Bed FlatFlat 4, 17, Adamson Road, London, NW3 3HUFlat 4, 17, Adamson Road, London, NW3 3HU
• Sold Jan 2015£1,960,000 | 3 Bed FlatFlat 3, 18, Belsize Square, London, NW3 4HTFlat 3, 18, Belsize Square, London, NW3 4HT
• Sold Jan 2014£1,800,000 | 3 Bed FlatFlat 3, 15, Belsize Park Gardens, London, NW3 4JGFlat 3, 15, Belsize Park Gardens, London, NW3 4JG
• 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
• Sold Aug 2012£1,253,000 | 3 Bed FlatFlat 1, 16, Belsize Park Gardens, London, NW3 4LDFlat 1, 16, Belsize Park Gardens, London, NW3 4LD
• Sold Jan 2010£731,000 | 4 Bed FlatFlat 4, 40, Belsize Square, London, NW3 4HLFlat 4, 40, Belsize Square, London, NW3 4HL

Over the past 2 years our Estate Agent network has recorded 2 lets within 280 metres of 12C, Belsize Square.

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

• 
  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.

Of the 264 addresses on Belsize Square, London, NW3, 12C, Belsize Square comes out as the 22nd largest and the 24th most expensive in our analysis of the public data.

It is also £406k more expensive than the average property across the NW3 district.

• 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

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