Designed to Be Entered: What Open House London Reveals About the Architecture We Actually Live In

Architecture is the one art form judged almost entirely from the outside — and lived almost entirely from the inside. Open House London is the week that gap gets tested in public.

From 12 to 20 September 2026, the 35th Open House Festival throws open more than 800 buildings across all 33 London boroughs, for free — private homes, working offices, civic landmarks and infrastructure that are normally shut. Londoners queue for hours to get inside No 10, Broadcasting House, the BT Tower and, this year, Richard Rogers' Lloyd's Building as it turns 40. It looks like architectural tourism. It is actually a mass public audit of a question most buildings would rather you did not ask: is the inside as good as the picture?

That question matters because the two are decided at completely different moments. The exterior is what a building is photographed as — the render, the skyline shot, the thing that wins the commission. The interior is what it is, once people are moving through it, and it is fixed far upstream, in the plan and the section, long before any facade is styled. Open House is valuable precisely because it strips the render away and leaves only the lived experience: the threshold you walk through, the light you stand in, whether the space makes room for you or holds you at arm's length.

No building states the point more literally than Lloyd's. Rogers pushed the staircases, lifts, pipes and ducts onto the outside of the building — the move critics nicknamed "Bowellism" — for one reason: to leave the inside as an uninterrupted trading floor that could expand, contract and reconfigure as the market changed. The famous facade is a by-product. The real decision was about the life within — a building engineered so its floors can be added or removed without touching the structure. It was, quite literally, designed from the inside out.

That is the discipline Open House rewards, and it is a concept-phase discipline. You cannot retrofit generosity. Whether a building welcomes a stranger at the door, whether its shared spaces feel civic or defensive, whether the plan is legible enough that you know where to go — these are set in the first moves, in the arrangement of volumes and thresholds, and they are almost impossible to fix later with materials or signage. Rogers understood this even at the entrance: he preserved the old triumphal-arch doorway of the earlier building as a deliberate civic gesture, a threshold that acknowledges the person arriving. The buildings that fail Open House are the ones that got the opposite right — an unimprovable exterior wrapped around a mean, confusing or hostile interior.

The festival's own range is the argument. A programme that runs from Georgian terraces to contemporary social housing, from the Zaha Hadid Foundation archive opening for the first time to a Victorian pumping station, puts a starchitect icon and a council flat on the same footing — judged by the same test, which is simply: what is it like to be inside? That is a profoundly democratic way to evaluate design, and a clarifying one. It says the measure of a building is not how it photographs but how it behaves when a person walks in cold.

There is a lesson well beyond architecture. Almost everything now is consumed first as an image — a render, a thumbnail, a hero shot — and the temptation is always to optimise for that image and defer the harder question of the lived experience. Open House is a reminder that the image is not the thing. The parts that decide whether a design actually works for the human using it are settled early, in the bones, where they are cheap to get right and ruinous to ignore. Designing from the inside out — deciding the experience first and letting the surface follow — is exactly the work we obsess over at Depix.

Sources:

• ●Open House Festival 2026 (Open City)
• ●Open House Festival programme (Open House)
• ●Open House London 2026: Free Architecture Festival (TNT Magazine)
• ●Open House 2026 Unlocks London's Iconic Buildings (FACT)
• ●London Open House Festival (Guide London)
• ●Lloyd's building is Richard Rogers' first high-tech office block (Dezeen)
• ●Inside Lloyd's Building: Richard Rogers' vision (ArchEyes)
• ●Lloyd's Building: An Architectural Icon (Institution of Civil Engineers)
• ●Richard Rogers: high-tech's inside-out architect (Dezeen)
• ●Inside and outside the inside-out building (London On The Ground)
• ●Lloyd's set for once-in-a-generation redesign (Architects' Journal)
• ●Open House Festival 2026 (The London Archives)