London has an unusually strong line-up of free events on Saturday 19 and Sunday 20 September 2026, as the final weekend of Open House Festival overlaps with the closing weekend of London Design Festival. The programme includes free access to the Royal Courts of Justice, a rare weekend opening at the Bank of England Museum, medieval Guildhall, historic Temple Bar, normally restricted buildings across the capital and London Design Festival installations that disappear after Sunday. London Construction Magazine checked the current official event and venue pages rather than relying on general weekend listings. That matters because access arrangements vary sharply: the Royal Courts of Justice is Saturday-only, the Bank of England Museum opens from 11:00 rather than 10:00, and some Open House tours require tickets even where general building access remains free and unticketed.
Best free things to do in London this weekend
| Free event | When | Access |
|---|---|---|
| Royal Courts of Justice Open Day | Saturday, 10:00–16:00 | Free drop-in |
| Bank of England Museum | Saturday and Sunday, 11:00–16:00 | Free, no booking required |
| Guildhall Great Hall | Saturday and Sunday, 10:00–16:00 | Drop-in |
| Pearly Kings and Queens Harvest Festival | Sunday from 13:30 | Free outdoor event |
| The Pangolin Shield | Saturday and Sunday, all day | Free, no ticket required |
| Temple Bar | Saturday and Sunday, 10:00–16:00 | Unticketed, admissions every 30 minutes |
| Hackney Empire | Sat 10:30–15:00; Sun 10:30–16:00 | Free auditorium access; tours booked separately |
| Van Gogh House London | Saturday and Sunday, 10:00–17:00 | Open House drop-in |
| Battle of Britain Bunker Generator House | Saturday and Sunday, 10:00–16:00 | Free, no booking required |
| Once Upon A Garden at the V&A | Saturday and Sunday, 10:00–17:00 | Free, no ticket required |
Royal Courts of Justice opens its doors on Saturday
One of the strongest one-day opportunities is the Royal Courts of Justice Open Day on the Strand. HM Courts & Tribunals Service confirms that the building will open from 10:00 to 16:00 on Saturday. Visitors can see mock trials, judicial clothing and historic material, hear presentations on the work of the courts and view the cells and prisoner transport vehicles. Open House also confirms free drop-in access to the Victorian Gothic building, completed in the 19th century to designs by G E Street. For architecture enthusiasts, the Great Hall is a reason to visit on its own. The space is approximately 230 ft long and 82 ft high, with rib vaulting, stonework and Gothic detailing more associated with a cathedral than a working court complex.
Bank of England opens on both weekend days
The Bank of England Museum's official Open House notice confirms a rare Saturday and Sunday opening from 11:00 to 16:00, with last entry at 15:30. Admission is free and no booking is required, although visitors pass through airport-style security. The weekend also gives visitors access to the new Mrs Coade's Stone display and the temporary A Kind of Exchange exhibition produced with the Royal College of Art for London Design Festival. The Museum includes material on the architecture of the Bank and allows visitors to try lifting a real gold bar. The building is also relevant to London's live construction market. London Construction Magazine has previously tracked the Bank of England refurbishment within London's 2026 project pipeline, where the institution's major estate works sit alongside other complex central-London refurbishment programmes.
Guildhall and the Pearly Kings and Queens
Guildhall is open from 10:00 to 16:00 on both days. The Grade I listed Great Hall is one of the City's most important surviving medieval civic spaces and has remained at the centre of London government for centuries. Sunday adds a completely different reason to visit. The London Pearly Kings and Queens Society confirms that its 2026 Costermongers Harvest Festival will begin in Guildhall Yard at 13:30 on 20 September. The annual charity event brings the Pearly tradition into the Square Mile with music, dancing and the group's harvest celebrations. Close by, Sir Christopher Wren's Temple Bar will also open free from 10:00 to 16:00 on Saturday and Sunday. The restored 1672 structure is the only surviving historic City gate and is normally far less accessible than the surrounding public space at Paternoster Square.
London Design Festival ends on Sunday
London Design Festival runs until Sunday 20 September, so this is the final weekend to see its 2026 installations. One of the strongest construction and engineering entries is The Pangolin Shield by Studio Saar and structural engineer Atelier One at Strand Aldwych. The free, unticketed pavilion uses a bamboo grid shell covered with traditional Indian bamboo police shields and woven rain shields. The Festival lists the installation as open all day on both Saturday and Sunday. At the V&A, Once Upon A Garden runs from 10:00 to 17:00 on both days with no ticket required. The installation uses digital imagery to examine extinct and critically endangered plants for which little visual evidence survives.
Free architecture beyond central London
Open House is not limited to Westminster and the Square Mile. Hackney Empire is offering free access to its Grade II* listed auditorium across both days, while Van Gogh House in Stockwell opens the conserved Grade II listed home where Vincent van Gogh lived during his time in London. For engineering history, the Battle of Britain Bunker Generator House in Uxbridge is another unusually strong option. The preserved building contains its 1930s standby diesel generator and associated equipment and is not part of the site's normal public tour. These openings also show why heritage construction is often less about creating something visibly new and more about keeping existing fabric usable. LCM's coverage of restoration works at the Tower of London has examined the same interaction between conservation, access, temporary works and public use, while our London retrofit contractor analysis tracks the growing workload behind adapting existing buildings rather than replacing them.
Check access before travelling
Free does not always mean unrestricted. The Bank of England and Royal Courts of Justice operate security checks, some Open House guided tours require separate advance tickets, and individual buildings can limit entry when safe capacity is reached. Anyone planning a visit should therefore check the official venue or festival listing again on Friday 18 or Saturday 19 September. Both Open House Festival and London Design Festival finish on Sunday 20 September, so many of the one-off openings listed above will not remain available the following week.
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Expert Verification & Authorship: Mihai Chelmus Founder & Editor, London Construction Magazine | Construction Testing & Investigation Specialist |