21, William Square has an Energy Performance Rating (EPC) of C. This is based on the most recent assessment, dated 13 Oct 2021.

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

The most recent sale of 21, William Square completed on 13th February 2026 at £425,000 and was recorded by HM Land Registry as a leasehold flat.

Since 1995 the property has sold 3 times.

Values of comparable properties have dropped by 13.4% over the period since February 2026.

• Sold Feb 2026£425,000
• Sold Sep 1997£130,000
• Sold Aug 1995£119,995

Since 2015 161 properties similar to 21, William Square have sold within a radius of 400 metres, per the Land Registry and our network of Estate Agents.

The latest, on the 16th October 2025, was Flat 101, Globe Wharf 205, Rotherhithe Street, London, SE16 5XX, a leasehold flat which sold for £425,000.

Read more about house prices in SE16.

• Sold Oct 2025£425,000 | 2 Bed FlatFlat 101, Globe Wharf 205, Rotherhithe Street, London, SE16 5XXFlat 101, Globe Wharf 205, Rotherhithe Street, London, SE16 5XX
• Sold Jul 2025£440,000 | 2 Bed FlatFlat 35, Lamb Court 69, Narrow Street, London, E14 8EJFlat 35, Lamb Court 69, Narrow Street, London, E14 8EJ
• Sold May 2025£332,500 | 2 Bed Flat4, Sophia Square, London, SE16 5XL4, Sophia Square, London, SE16 5XL
• Sold Aug 2024£465,000 | 2 Bed Flat9, Sophia Square, London, SE16 5XL9, Sophia Square, London, SE16 5XL
• Sold May 2024£467,500 | 2 Bed Flat1, Sophia Square, London, SE16 5XL1, Sophia Square, London, SE16 5XL
• Sold Mar 2024£375,000 | 2 Bed Flat26, Helena Square, London, SE16 5XP26, Helena Square, London, SE16 5XP
• Sold Nov 2023£450,000 | 2 Bed Flat24, Frederick Square, London, SE16 5XR24, Frederick Square, London, SE16 5XR
• Sold Sep 2022£506,000 | 2 Bed Flat33, William Square, London, SE16 5XJ33, William Square, London, SE16 5XJ
• Sold Sep 2022£492,500 | 2 Bed Flat32, Elizabeth Square, London, SE16 5XN32, Elizabeth Square, London, SE16 5XN
• Sold Aug 2022£465,000 | 2 Bed Flat83, Bywater Place, London, SE16 5NE83, Bywater Place, London, SE16 5NE
• Sold Jun 2022£480,000 | 2 Bed Flat33, Edward Square, London, SE16 5EE33, Edward Square, London, SE16 5EE
• Sold Jan 2022£475,000 | 2 Bed Flat24, Admiral Place, London, SE16 5NY24, Admiral Place, London, SE16 5NY
• Sold Dec 2020£465,000 | 2 Bed Flat2, Admiral Place, London, SE16 5NY2, Admiral Place, London, SE16 5NY
• Sold Sep 2020£435,000 | 2 Bed Flat39, William Square, London, SE16 5XJ39, William Square, London, SE16 5XJ
• Sold Mar 2020£475,000 | 2 Bed Flat23, Sophia Square, London, SE16 5XL23, Sophia Square, London, SE16 5XL
• Sold Jul 2019£490,000 | 2 Bed Flat29, Edward Square, London, SE16 5EE29, Edward Square, London, SE16 5EE
• Sold Oct 2018£525,000 | 2 Bed Flat11, Edward Square, London, SE16 5EE11, Edward Square, London, SE16 5EE
• Sold Jun 2018£405,000 | 2 Bed Flat25, Edward Square, London, SE16 5EE25, Edward Square, London, SE16 5EE
• Sold Feb 2016£590,000 | 2 Bed Flat23, William Square, London, SE16 5XJ23, William Square, London, SE16 5XJ
• Sold Dec 2015£440,600 | 2 Bed Flat21, Admiral Place, London, SE16 5NY21, Admiral Place, London, SE16 5NY

Of the 39 addresses on William Square, London, SE16, 21, William Square comes out as the 17th largest and the 17th most expensive in our analysis of the public data.

It is also £51k less expensive than the average property across the SE16 district.

• Peter Hills with St Mary's and St Paul's CofE Primary School

  300 m away
• Redriff Primary, City of London Academy

  600 m away
• Cyril Jackson Primary School

  700 m away

• Bacon's College

  600 m away
• Stepney All Saints Church of England Secondary School

  1.1 km away
• Bishop Challoner Catholic School

  1.2 km away

• Limehouse

  |

  600 m away
• Westferry

  |

  800 m away
• West India Quay

  |

  1.2 km away

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