What if you could step inside some of London’s most fascinating buildings ... for FREE? That’s exactly what Open House Festival is all about.
From 12–20 September 2026, hundreds of buildings and spaces across London will be free to visit as part of Open House Festival. This includes places that are normally closed to the public and opening their doors especially for the festival, alongside buildings and landmarks that you can visit throughout the year but are offering free access or special events during the festival.
Today, DOYOUSPEAKLONDON takes you behind the doors of Open House Festival!
What is Open House Festival London?
Open House Festival is the world's largest architecture festival, and it happens right here in London every September! For nine days, over 800 buildings across all 33 boroughs throw open their doors to the public. Free of charge.
It's organised by Open City, a London charity founded by Victoria Thornton back in 1992. That first year, there were just 20 buildings and around 100 visitors, carted around town in a minibus.
The idea is simple, but genuinely powerful: London is full of buildings we walk past every day and never get to enter. Private homes, government offices, working studios, archives, factories.
For one week, that changes.
You get behind-the-scenes access to places usually locked to outsiders, guided by the people who actually work, live or create inside them.
Since then, it's grown into a genuine phenomenon. By 1994, it was 200 buildings. By the 2010s, over 800, with hundreds of thousands of visitors every year. The concept has since been adopted by more than 60 cities worldwide, from Athens to New York.
The format itself has quietly evolved too. What used to be a single, chaotic weekend is now a full nine-day programme, running from Saturday 12 to Sunday 20 September 2026.
What makes Open House Festival so special?
A few things really stand out for me, especially the incredible variety of places to discover, and the chance to see London from a completely different perspective.
1. You discover places you'd never normally step inside
That's the whole magic of it. This year's programme includes tours of No 10 Downing Street, BBC Broadcasting House and the BT Tower, alongside the Lloyd's Building and Mansion House, the Lord Mayor's official residence.
There's also Two Temple Place, William Waldorf Astor's extraordinary 1895 neo-Gothic mansion on the Embankment, with a staircase carved with characters from The Three Musketeers and a Great Hall lined in Spanish mahogany.
Then there's the quieter, stranger stuff: the Zaha Hadid Foundation archive in Clerkenwell, the Isokon Building in Belsize Park (where Agatha Christie once lived), the rarely-opened Punchdrunk Enrichment Stores in Wembley, and even the Southwark Integrated Waste Management Facility.
Doors that are usually firmly shut, suddenly aren't. And there are plenty of them as you will see in the website!
2. It's completely free
Every single Open House Festival event costs nothing. Some need advance booking, others are simple drop-ins, but the price tag is always zero.
Pitzhanger Manor, Ealing
In a city where everything feels increasingly expensive, it's a detail that matters.
3. The guided visits are where it really shines
Some buildings offer guided tours led by architects, curators or even the people who own the space. You can feel the passion Open City and its volunteers put into this, and it genuinely elevates the experience from "nice building" to "I actually understand this place now."
That's exactly what I got a taste of at Olympia. As part of the festival, visitors can join a guided tour of the transformed venue and stand inside the Grade II listed Pillar Hall, walking through the ten-year project that's reimagined this Victorian landmark, from its striking glass canopy to the new elevated street running through it.
It's also worth knowing that Open City isn't just a September event organiser. It runs year-round architecture walks, works with 50 London schools, and mentors young people who are traditionally excluded from architecture careers through its Accelerate scheme. The festival funds all of it.
Discovery of Olympia with the team behind Open City!
That context changed how I see the festival, honestly. It's not just a fun festival. It's a charity doing real, ongoing work, with this festival as its biggest platform.
Feeling inspired? If you're planning a visit to Open House Festival, I'd love to hear about your experience on DOYOUSPEAKLONDON!
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Everything you need to know about Open House Festival London:
Dates: 12–20 September 2026, times vary by venue (check individual listings on the programme)
Tickets: Free entry to all events. Most are drop-in; some require advance booking, which opens at midday on Wednesday 19 August 2026 via a free Open City account.
Website: programme.openhouse.org.uk (you need to create a free account to participate in the festival).
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