Adding interior walls — and laying out a real apartment
Interior walls are what turn an empty footprint into rooms. Here's the full set of techniques — perpendicular and free-angle drawing, extending by length or by dragging a corner, moving a whole wall — applied to a real 1-bedroom apartment with an open kitchen, dining, and living.
An empty room is just a shape. Walls inside it are what turn it into a home. Today we lay out a whole apartment — one bedroom, one bath, an open kitchen, dining, and living — from a single outer rectangle, using interior walls.
This is the long version, on purpose. Every interior-wall technique you'll need: drawing perpendicular walls with the 90° snap (the default — and what you want most of the time), drawing free-angle walls when you don't, editing a wall's length by typing it in or by dragging a corner, and moving a whole wall to reposition it. Then doors and auto room detection do the rest.
What you'll need
- •An outer floor plan to add interior walls to — see How to create a rectangular floor plan or Drawing a custom-shaped room.
- •A rough idea of the rooms you're carving out. We'll use a 1-bedroom, 1-bathroom apartment with an open kitchen, dining, and living as the worked example.
Step by step
- 1
Start with the outer shape
Open a floor plan that already has the outer walls drawn — your apartment's perimeter — but no interior walls yet. (If you haven't drawn the outer shape, see How to create a rectangular floor plan or Drawing a custom-shaped room first.) The example here is a 1-bedroom, 1-bathroom apartment: outer rectangle, one front door, that's it. The shape is done; the rooms aren't.
Start with the outer shape — perimeter drawn, no rooms inside yet. - 2
Pick the Interior Wall tile
Open the Room Structure panel on the left and click the Interior Wall tile (top-left of the 3×3 grid). That puts you in interior-wall drawing mode — every click on the canvas starts or ends a wall.
Interior Wall lives in the Room Structure panel, top-left of the 3×3 grid. - 3
Draw perpendicular walls (90° snap — the default)
By default, interior walls snap to 90 degrees — they lock perpendicular to your outer walls and to the grid. Click where the wall starts, drag, click where it ends. That's the wall. This is what you want almost all the time. Real homes are mostly right angles, and the snap means your walls are square without you having to be careful. For the apartment, the kitchen, dining, and living are an open layout — they share one big space and we don't draw any walls between them. So the interior walls we draw carve out only the bedroom and the bathroom. Click, drag, click — four perpendicular walls and the two private rooms are roughed in.
Click → drag → click. The wall snaps perpendicular to outer walls and the grid. - 4
Draw free-angle walls when you need a diagonal
Most homes are right angles, but not every wall is. A diagonal partition, a corner cut, a wall at the back of an alcove — sometimes you need the wall to point wherever you point it. Hold the modifier (or toggle the snap off) and the wall draws free-angle: whatever direction you drag, that's the wall you get. Same click-drag-click — just without the right-angle assumption. Most apartments won't use this — but knowing it exists means you're not stuck when the layout calls for it.
- 5
Edit a wall — by length, by drag, or by moving the whole thing
Once a wall is in, you can change it three ways. One — type the exact length. Select the wall and the inspector shows its current length. Type the value you want: twelve feet, six inches; three meters. The wall resizes. Use this when you have a real apartment dimension you're matching. Two — drag a corner. Grab the endpoint of a wall and pull. The wall stretches; the rooms on either side resize live as you drag. Use this when you don't have a number — you have a shape. Three — move the whole wall. Grab the wall by its middle and drag. The wall translates as a unit; the rooms on either side adjust accordingly. Fastest way to shift a partition a few inches when you're balancing room sizes.
Type a length, drag a corner, or drag the wall's middle to move the whole thing. - 6
Add doors so the rooms connect
Bedrooms and bathrooms need doors. Drop one in from the same Room Structure panel — the flow is identical to placing exterior doors (see Adding doors: hinged, sliding, and French). One door for the bedroom, one for the bathroom. The kitchen, dining, and living don't get doors between them — that's what "open" means.
- 7
Watch the rooms appear — auto room detection
As soon as the walls enclose a space, Room Sketch 3D recognises it as a room. Names float above each room with its dimensions — Living, Dining, Kitchen, Bedroom, Bathroom — and you can click any beacon in the 3D view to jump straight there. You don't label rooms; the app does. (See Auto room detection and naming.)
Walls enclose, rooms get named automatically: Living, Dining, Kitchen, Bedroom, Bathroom. - 8
Walk it in 3D
Switch to 3D and walk the apartment. Front door opens into the open kitchen / dining / living — no walls between them, that's the layout. Walk past the partition into the bedroom, out, into the bathroom, out. The shape became a home. See Switching to 3D and walking through your home.
Tips
Keep the 90° snap on until you actually need it off
The snap is the difference between a tidy apartment plan and a wonky one. Free-angle is a tool for the moments you truly need a diagonal — not a default. Toggle it on, draw the diagonal wall, toggle it back off.
Type the dimension when you have one
If you measured the real bedroom and it's 12 feet by 10 feet, type those numbers. Dragging walls is great for sketching; typing is what makes the plan match the real space.
Move walls when you're balancing rooms
If the bedroom feels small but you've got room to give it from the living area, grab the partition's middle and drag — both rooms resize at once. It's the fastest way to find the right balance.
Open layout = no interior walls between those spaces
The whole point of an open kitchen / dining / living is that there's nothing between them. Don't draw walls there, and let auto-detection figure out the boundaries (the room beacons settle at the natural centers of each functional area).
Walk it in 3D before you commit
A floor plan that reads well in 2D can have a doorway that opens at an awkward angle, a sightline you didn't want, or a partition that feels closer in person. The 3D walk catches it.
Common mistakes
Drawing walls with snap off because you're 'eyeballing it'
Free-angle walls that should have been perpendicular create rooms that look off — at first glance and in 3D. If the wall should be at 90°, let the snap put it there. The snap is on for a reason.
Drawing walls between rooms that should be open
An open layout is defined by what isn't there. If you find yourself reaching for the Interior Wall tile to separate the kitchen from the dining, ask whether you actually want that wall. Open layouts feel bigger because they are.
Editing by drag when you have the number
Dragging until 'that looks right' is fine for sketching. But if you know the bedroom is 12 feet wide, type 12 feet. The plan is only as accurate as the measurements you put into it.
Forgetting the door
A bedroom with no door is technically a closet. Drop the door in as soon as the walls are placed — Smart Flow Check will start checking the swing arc against your furniture from the moment the door exists.
Frequently asked questions
What's the difference between interior walls and outer walls?
Outer walls define the shape of your home — the perimeter you drew when you created the floor plan. Interior walls split that shape into rooms. Interior walls don't change the outer footprint; they just carve it up.
How do I draw an interior wall that isn't at 90 degrees?
By default the Interior Wall tool snaps to 90° (perpendicular). Hold the modifier — or toggle the snap off — and the wall draws at whatever angle you point it. Useful for diagonal partitions, alcoves, and corner cuts. Re-enable the snap once you've drawn the angled wall so the rest stay square.
Can I make an interior wall a specific length?
Yes — select the wall and type the length in the inspector. The wall resizes to match. You can also drag the wall's endpoint to extend or shorten it visually, or drag it from the middle to move the whole wall.
How do I move an interior wall after I've drawn it?
Grab the wall in the middle and drag. The wall translates as a unit, and the rooms on either side resize live. To move just one endpoint, drag the corner instead.
Do I need to label the rooms after I draw the walls?
No — as soon as the walls enclose a space, Room Sketch 3D auto-detects the room and gives it a name based on its size and shape. You can rename any room if the suggestion isn't right. See Auto room detection and naming.
Why is my 'open kitchen / dining / living' showing as one room?
Because it is one room. An open layout is defined by the absence of walls between those areas, so auto-detection sees it as a single enclosed space. That's correct behaviour — and the room beacons settle around the functional centers of the space.
Can an interior wall have a door or a window in it?
Yes — interior walls work like outer walls when it comes to features. Place a door (any type — hinged, sliding, French) or an opening or even a window on an interior wall just like you would on the perimeter. See Adding doors and Adding fireplaces and wall openings.
Start designing your room
Draw it, furnish it, walk through it in 3D — on web, iOS, and Android.
Open Room Sketch 3DOne-time purchase · No subscription · Web, iOS & Android