INT. vs EXT. in a Screenplay: When to Use Each

What INT. and EXT. stand for

INT. is interior. EXT. is exterior. The period after each abbreviation is part of the convention, not the end of a sentence.

INT. KITCHEN - NIGHT
EXT. HIGHWAY OVERPASS - NIGHT

The test is enclosure, not walls. A scene is an interior when the action happens inside a structure that has a roof over it and walls around it — somewhere that would need artificial light, somewhere weather cannot reach, somewhere the production might plausibly build on a stage. Everything else is an exterior, shot on location in whatever light the sky provides.

One useful way to hold the distinction: INT. is a promise about control. It says the crew can black out the windows, place the lights, hold the sound and shoot the scene at any hour of the day or night. EXT. says the opposite — the light comes from outside the production's control, and the scene is tied to a real time of day and a real piece of ground.

The combined heading: INT./EXT. and EXT./INT.

When a single scene genuinely moves between the outside and the inside of something, the heading carries both, with the first term naming where the scene starts:

INT./EXT. CAR - NIGHT
EXT./INT. FARMHOUSE - CONTINUOUS

INT./EXT. is by far the more common form, and the car is the reason why. A scene where a driver pulls up, gets out and the camera follows is one dramatic unit that crosses the boundary of the vehicle. So is a scene that walks in through a doorway and stays with the character.

Use the combined form sparingly, and only when the scene is genuinely one continuous piece of action. Two separate beats — a conversation in a car, then a walk into a house — are two scenes with two sluglines, even if they are joined by a move. Readers are not confused by a new heading; they are confused by a heading that does not match what they just read.

You will also see the abbreviated I/E. in older shooting scripts and in breakdown sheets. It means the same thing. Do not introduce it into a spec script.

What counts as an interior

The objects below are enclosed even though they do not look like rooms, and the dominant practice is INT. for all of them:

• Vehicle interiors. INT. CAR - NIGHT, INT. TRAIN CAR - DAY, INT. HELICOPTER - DUSK. The scene plays inside the vehicle, so the heading says interior even when the camera is mounted on the hood looking in.
• Tents, trailers, containers. INT. FIELD TENT - NIGHT. Fabric is still a roof.
• Caves, tunnels, mines. INT. CAVE - DAY. Even in daylight these need artificial light, and this is where the neat rule and real life part company — see the next section.
• Submarines, ships' holds, aircraft cabins. INT. SUBMARINE - CONTROL ROOM - NIGHT. You cannot photograph a submarine's interior from outside it.
• Phone booths and elevators. INT. PHONE BOOTH - DAY, INT. ELEVATOR - NIGHT. Small, but roofed and walled on every side.
• Greenhouses, pool houses, barns. Glass and timber still enclose, and the scene is lit and shot like an interior.

Two near-misses are worth naming. A PORCH has a roof, but the convention is EXT. PORCH, because it belongs to the exterior of the building, sits in ambient daylight and is usually covered in the schedule as part of the location's outside. A CARPORT works the same way. If a roof is the only thing a space has going for it, it is still outside.

Grey areas, and what most working writers do

A handful of locations are genuinely contested. The dominant practice below is what you will find in the majority of produced scripts and in the breakdown conventions that schedulers work from.

When you are genuinely torn, ask which version of the heading would help the person breaking the script down. That is not a cop-out; it is the convention's original purpose. Wrapping the exterior of a building with lights and blacking out adjoining windows is a different job from walking onto a stage, and the heading is how the production finds out which job it is.

Why a first AD and a location manager care

The two letters sit at the top of every breakdown sheet, next to day or night, and they drive real decisions:

• Lighting package. An interior is lit from scratch, which means a truck of equipment, a rigging crew and a set-up time measured in hours. An exterior uses whatever the sky gives and is scheduled around the sun.
• Location and permits. An exterior means a real address: permissions, parking, neighbours, a police officer for traffic control, fees. A stage build avoids all of it.
• Weather and cover. Exteriors carry a weather risk and often need a cover set — an interior held ready to shoot if the sky turns. That line item exists because your heading said EXT.
• Shoot order. Strips are sorted by location first, then by day or night. A script that alternates between a farmhouse interior and a city exterior every four pages is more expensive to shoot than the same scene count grouped together, and the AD sees that before anyone reads a word of dialogue.
• Night work. All-night exteriors mean overtime, permits with curfews, generators and noise limits. Night interiors can be shot at eleven in the morning with the windows blacked out — which is a scheduling advantage you only get if the heading is honest about being an interior.
• Continuity. A location that appears as EXT. STREET - DAY on page 40 and EXT. STREET - NIGHT on page 41 is two separate trips to the same street, months apart, matching the same parked cars. A tight script groups those appearances deliberately.

None of this means you should bend a scene to save money. It means the heading is a production instruction as well as a reader's signpost, and getting the two letters right costs you nothing.

Common INT./EXT. errors

Three of those eight rows are the same mistake in different clothes: the writer wrote where the camera was standing instead of where the scene takes place. The heading describes the scene, and the shots follow the heading.

Worked the other way round, a correctly built sequence reads like this — and every heading tells the scheduler something:

EXT. FARMHOUSE - DUSK

The truck pulls in. HELEN cuts the engine and sits a moment.

INT. FARMHOUSE - KITCHEN - CONTINUOUS

Helen sets the keys down. The room is dark.

Two locations, one continuous moment, one exterior in magic-hour light and one interior that can be shot at any hour. That is a cheap sequence to make, and the reader can see it without being told.

Frequently asked questions

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