1, Onslow Square has an Energy Performance Rating (EPC) of D. This is based on the most recent assessment, dated 03 Sep 2019.

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

1, Onslow Square last changed hands on 22nd March 2021, selling for £2,300,000. The transaction was logged as a leasehold flat by HM Land Registry.

That is its only recorded sale since 1995.

The market for similar properties has dropped by 25.5% since March 2021.

• Sold Mar 2021£2,300,000

Land Registry records and our Estate Agent network show 18 sales of comparable properties within 290 metres of 1, Onslow Square since 2008.

Most recently, Flat 2, 11, Onslow Square, London, SW7 3NJ, a leasehold flat, sold at £2,750,000 on the 20th November 2025.

Read more about house prices in SW7.

• Sold Nov 2025£2,750,000 | 3 Bed FlatFlat 2, 11, Onslow Square, London, SW7 3NJFlat 2, 11, Onslow Square, London, SW7 3NJ
• Sold Nov 2024£2,825,000 | 3 Bed FlatFlat 2, 23, Onslow Square, London, SW7 3NJFlat 2, 23, Onslow Square, London, SW7 3NJ
• Sold Oct 2022£3,100,000 | 3 Bed Flat42, Rose Square, London, SW3 6RS42, Rose Square, London, SW3 6RS
• Sold Aug 2022£3,600,000 | 3 Bed FlatFlat 1, 17, Onslow Square, London, SW7 3NJFlat 1, 17, Onslow Square, London, SW7 3NJ
• Sold Oct 2018£2,650,000 | 3 Bed FlatFlat 2, 52, Onslow Square, London, SW7 3NXFlat 2, 52, Onslow Square, London, SW7 3NX
• Sold Jun 2018£3,000,000 | 3 Bed FlatFlat 1, 38, Onslow Square, London, SW7 3NSFlat 1, 38, Onslow Square, London, SW7 3NS
• Sold Jan 2017£3,000,000 | 3 Bed Flat63, Onslow Square, London, SW7 3LS63, Onslow Square, London, SW7 3LS
• Sold Mar 2016£4,400,000 | 3 Bed Flat19, Onslow Square, London, SW7 3NJ19, Onslow Square, London, SW7 3NJ
• Sold Feb 2016£2,550,000 | 3 Bed FlatFlat 1, 46, Onslow Square, London, SW7 3NXFlat 1, 46, Onslow Square, London, SW7 3NX
• Sold Mar 2015£3,250,000 | 3 Bed FlatFlat 5, 52, Onslow Square, London, SW7 3NXFlat 5, 52, Onslow Square, London, SW7 3NX
• Sold Feb 2015£3,100,000 | 3 Bed FlatFlat 4, 52, Onslow Square, London, SW7 3NXFlat 4, 52, Onslow Square, London, SW7 3NX
• Sold Dec 2014£3,950,000 | 3 Bed FlatFlat 6, 81, Onslow Square, London, SW7 3LTFlat 6, 81, Onslow Square, London, SW7 3LT
• Sold Nov 2014£3,250,000 | 3 Bed FlatFlat 5, 38, Onslow Square, London, SW7 3NSFlat 5, 38, Onslow Square, London, SW7 3NS
• Sold May 2014£3,900,000 | 3 Bed FlatFlat 3, 38, Onslow Square, London, SW7 3NSFlat 3, 38, Onslow Square, London, SW7 3NS
• Sold Feb 2013£2,300,000 | 3 Bed FlatFlat 5, 5, Onslow Square, London, SW7 3NJFlat 5, 5, Onslow Square, London, SW7 3NJ
• Sold Jan 2011£2,250,000 | 3 Bed FlatFlat 3, 89, Onslow Square, London, SW7 3LTFlat 3, 89, Onslow Square, London, SW7 3LT
• Sold Nov 2008£2,400,000 | 3 Bed Flat50, Rose Square, London, SW3 6RS50, Rose Square, London, SW3 6RS
• Sold Mar 2008£2,950,000 | 3 Bed Flat51, Rose Square, London, SW3 6RS51, Rose Square, London, SW3 6RS

Our analysis of the public data ranks 1, Onslow Square as the 174th largest and the 77th most expensive of the 321 addresses on Onslow Square, London, SW7.

Against the SW7 postcode district average, it is £580k more expensive than the typical property.

• Oratory Roman Catholic Primary School

  300 m away
• Marlborough Primary School

  400 m away
• Our Lady of Victories RC Primary School

  500 m away

• St. Thomas More Language College

  700 m away
• Chelsea Academy

  1.8 km away
• The London Oratory School

  1.9 km away

• South Kensington

  |

  200 m away
• Gloucester Road

  |

  700 m away
• Knightsbridge

  |

  1.0 km away

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