Flat 4, 17 Onslow Square, London, SW7 3NJ is a leasehold flat built between 1900-1929. The property offers approximately 1,184 square feet of living space and is situated on the 4th floor of a 6-storey building. In this location, apartments of similar size usually have four bedrooms.
The estimated current market value of the property is £1,748,286 , which equates to approximately £1,477 per square foot. It was last sold on 26 Aug 2003 for £725,000. Since then, the value has increased by £1,023,286, representing a 141.1% increase, or approximately 6.2% per year.
The current estimated value of £1,748,286 is:
This property has had 2 EPC inspections with recorded tenure information. It was recorded as owner-occupied both times. This suggests the property has typically been lived in by its owners, which often reflects longer-term residency and more consistent maintenance.
At the most recent EPC inspection on 16 September 2025, the property was recorded as owner-occupied.
Flat 4, 17 Onslow Square, London, Kensington And Chelsea, Greater London, SW7 3NJ has an Energy Performance Certificate (EPC) rating of C, based on the latest assessment carried out on 16 Sep 2025.
This property uses a gas-fired boiler and radiators, connected to the mains gas supply, as its main heating source. Hot water is provided from main heating system. The windows are single glazed.
The previous EPC assessment was conducted on 26 Sep 2014. The rating of C remains the same, but the energy efficiency score improved by 14.3%.
Since the previous assessment, several changes were observed:
* Results are based on Environment Agency flood risk mapping for the property UPRN where available. They are indicative and should not be treated as a site-specific flood survey.
This property has very low flood risk from rivers and the sea.
River and sea flooding includes flooding caused by overflowing rivers, estuaries, tidal waters and coastal surges.
This property has very low surface water flood risk.
Surface water flooding can happen when heavy rainfall overwhelms drains, roads, gardens or other hard surfaces.
The property at Flat 4, 17 Onslow Square, London, SW7 3NJ appears once in HM Land Registry records, with the transaction recorded on 26 Aug 2003. It also has three Energy Performance Certificate (EPC) records, the earliest dating back to 16 Sep 2025. We use this information to estimate the property's characteristics, flood risk profile and current market value.
This website uses public sector information from:
HM Land Registry Price Paid Data
Energy Performance of Buildings Data published by the Department for Energy Security and Net Zero (DESNZ) and the Ministry of Housing, Communities and Local Government (MHCLG).
Flood risk data supplied by the Environment Agency through the Department for Environment, Food & Rural Affairs (Defra) Data Services Platform.
These datasets are licensed under the Open Government Licence v3.0 .
StreetScan.co.uk is not affiliated with, endorsed by, or associated with HM Land Registry, DESNZ, MHCLG, Defra or the Environment Agency.