Gaps in an outside wall: where they come from and how to close them
A dashed stretch in the outline is a gap with no wall. It appears when you delete an outside wall, set its Type to Open, or move or shorten a wall after turning its link off (the link starts on, so an ordinary move never opens one). Select the gap and tap its + to fill it with a wall, or tap Remove area to take the floor behind it off the plan.
A gap is a dashed stretch of the outline with no wall in it. Deleting an outside wall leaves one, and so does setting a wall's Type to Open. Moving a wall can too, but only when you've turned its link off: a selected outside wall starts with its link on, so dragging it, pulling its end or typing its length stretches the walls beside it and the outline stays whole. Turn the link off and only that wall changes; the walls beside it stay where they were, and the space that opens between them stays as a gap. The floor underneath doesn't change, so a gap is easy to close again, and useful when you want an open side on purpose: a porch edge, a carport, an open-plan side onto a deck.
This page shows what a gap looks like, every way one appears, how to fill it again, how to take the floor behind gaps off the plan with Remove area (handy when an imported plan's outline takes in a yard or a neighbour's space), and the link button that decides whether a wall takes its neighbours with it or moves alone.
What you'll need
- •A design open in the editor
Step by step
- 1
Delete an outside wall: it leaves a gap
Tap an outside wall. The small bar beside it shows its length, a padlock, a link button, scissors and a red trash can; the panel below is titled Exterior wall. Tap the trash can (or Remove at the bottom of the panel). The wall disappears but its place stays in the outline as a dashed stretch, still selected, with a + in the middle. The rooms, floor and furniture don't change.
The trash can on the wall's bar deletes it, leaving a gap. - 2
What a gap looks like, and the + that fills it
A gap is drawn as a dashed line along the outline, blue and dotted while it's selected. Select it and a + sits in its middle (Fill this gap with a wall); its bar shows the length, the padlock and the link button, and the panel shows Type: Open. Tap the + and the wall is back, with the thickness and height of the walls beside it. A gap that lines up with a wall next to it simply becomes part of that wall.
A gap: dashed, with a + in the middle. Tap the + to put the wall back. - 3
Leave a side open on purpose: Type → Open
To open a side without deleting anything, select the wall and set Type to Open in its panel (the choices are Wall | Railing | Open). The wall becomes a gap exactly as above. Choose Wall again, or tap the gap's +, to close it. Railing keeps a low barrier there instead; see Wall types.
Type: Wall | Railing | Open. Open leaves a gap on purpose. - 4
Why a gap appeared when you moved a wall
The link button on the wall's bar decides what a move does. It starts solid blue, Joined walls move too: drag a wall outwards, drag the crosshair at one of its ends, or type a new length, and the walls beside it stretch to stay joined, bringing the interior walls attached to it along. No gap opens. Tap the link so it shows a broken link, Wall moves on its own, and the walls at its two ends stay put instead, so the outline opens up: the space between the moved wall and its old neighbours is drawn as dashed gaps. That's what you want when you're reshaping one wall and will fill or remove the gaps yourself. On a computer, hold Alt (Option on a Mac) while you drag to do the opposite of the button for that one drag, which is the usual way a gap appears by surprise.
Link off: the wall moves alone and gaps open. Link on: the neighbours stretch. - 6
A shorter typed length leaves a gap too
With the link on (the start), a typed length moves the end marked with the arrow and the wall beside that end comes along. Turn the link off first and a shorter length moves that end in on its own, leaving a dashed gap between it and the corner it used to reach (the pinned end stays put; tap the arrow to keep the other end instead). The gap keeps the outline closed, so your rooms still read correctly. Tap the gap's + if you wanted the wall to reach the corner after all, or Undo, turn the link back on and type the length again to have the next wall come with it.
Shorter typed length with the link turned off: a gap opens at the end that moved. - 7
Take the floor behind a gap off the plan: Remove area
Sometimes the outline takes in floor that isn't part of the house: an imported plan that ran round a yard, a courtyard or the neighbour's flat, or an extension you no longer want. The real outside wall is usually already there, as an interior wall. First turn the outside walls around that floor into gaps (tap each one and its trash can, or set Type to Open). Then select one of the gaps: when there's floor behind it, a red Remove area button sits on its bar, after the length, padlock and link. A single straight gap with nothing behind it doesn't offer it.
Select a gap with floor behind it: Remove area is on its bar. - 8
Check the red preview, then confirm
Tap Remove area and nothing changes yet: the plan shows what would happen. The gaps that go are dashed red, the floor that goes is shaded red, and the wall that will become the new outside wall is blue. Anything standing in that floor (furniture, interior walls, stairs, pillars and so on) is outlined in red. A bar at the top asks Remove these 3 gaps and the floor shown in red? with Cancel and Delete; when something is in the way it reads 1 item is in this area (outlined in red) and will be deleted with it. and the button is Delete all. To keep something, tap Cancel (or press Esc), drag it into the house, and tap Remove area again.
Red: what goes. Blue: the new outside wall. Delete all removes the chair too. - 9
What you get: the rooms stay, the inside wall becomes the outside wall
Confirm and the floor comes off the plan in one step (one Undo brings it all back). Your rooms are kept, and the interior walls along the cut become the outside walls there, keeping their doors, windows and height. The cut follows your rooms' walls, including walls that meet in a T: delete the outside walls of a corner bedroom and Remove area takes the bedroom off along its own walls, while the long wall it met stays an interior wall for the rest of its length. The house walls on either side keep their own windows and doors. A wall that stops a little short of the next one is carried on to meet it, so an imported plan doesn't lose a whole room over a small gap. When no interior walls join the two ends of the gaps, the floor is cut off in a straight line between them instead, leaving one gap there. That line can run at an angle, so look at the red preview first; if it isn't where you want the outside wall, Cancel, draw an interior wall along the line you want, and tap Remove area again.
The extra floor is gone; every room is kept. - 10
The new outside wall matches the rest of the outline
Tap the wall that became the outside wall: its panel now says Exterior wall, and it has the thickness of your other outside walls (6.5" here), even if it was a thinner interior wall, so the outside face runs straight on from the walls beside it. The room side of the wall stays exactly where it was; the extra thickness goes outward, so no room gets smaller. Change its Thickness in the panel if this wall should differ.
Now an Exterior wall at the outline's 6.5", flush with the walls beside it. - 11
On a phone
Tap the wall, then the trash can on its bar, or scroll the panel at the bottom to Type and choose Open. The gap shows dashed with its +; tap the + to close it. The link button sits on the same bar.
Phone: the gap, its +, and Type: Open in the panel below.
Tips
A gap is a wall slot, not a hole in the floor
The outline stays closed through a gap, so the floor and the plan's area are unchanged, and the room beside it keeps its shading, its name and size label and its flooring. Gaps can be moved, stretched and even built from (pull the + at a selected gap's end) like any wall. To take the floor itself away, use Remove area.
Turn the link off only for one-wall reshaping
The link starts on, so a whole side comes along when you move a wall. Turn it off when you want to reshape just that wall, then turn it back on (or reopen the design) before your next ordinary move.
Undo is one press away
Deleting, opening, moving and filling a wall can all be undone with Undo (Ctrl+Z, ⌘Z on a Mac).
Common mistakes
Deleting a wall to make the room smaller
Deleting leaves a gap; the floor stays the same size. To make a room smaller, drag the wall in or type a shorter length; with the link on (how it starts) the walls beside it follow.
Dragging a wall and wondering why the plan 'broke'
It didn't. The link was off (you turned it off, or held Alt / Option during the drag), so only that wall moved and the dashed stretches are gaps waiting to be filled. Undo, check the link is solid blue, and drag again; or keep the move and tap each gap's + if you want walls there.
Removing an area with furniture still in it
Everything outlined in red in the Remove area preview is deleted along with the floor. Cancel, move what you want to keep into the house, then tap Remove area again.
Trying to delete the last solid wall
At least one solid outside wall must remain, so the last one can't be deleted or set to Open. Choosing Open on it shows At least one outside wall has to stay a wall. To plan an open-air space, add a Yard from the floor menu. For a space with no walls at all (a patio, a deck, a garden), add a Yard instead (see Design your yard).
Frequently asked questions
What is the dashed line on my floor plan outline?
A gap: a stretch of the outline with no wall. It appears when you delete an outside wall, set its Type to Open, or move or shorten a wall with its link turned off. Select it and tap its + to fill it with a wall.
I deleted a wall by mistake. How do I get it back?
Undo, or select the dashed gap where the wall was and tap its + (Fill this gap with a wall). Walls removed before October 25, 2026 don't show as gaps; they keep the old Restore button in the panel instead: select the open side and tap Restore.
Why didn't the walls next to it move when I dragged a wall?
The link button on the wall's bar was off. It starts on (solid blue, Joined walls move too) each time you open a design, but once you turn it off it stays off for every outside wall until you turn it back on. Tap it so it's blue again and the neighbours stretch with the wall. On a computer, holding Alt (Option on a Mac) while dragging also does the opposite of the button for that one drag.
Can I leave a side open on purpose, for a porch or carport?
Yes. Select the wall and set Type to Open, or delete it. The floor stays, with no wall on that side in 2D or 3D. Choose Railing instead if there should be a low barrier.
My imported plan has floor outside the house. How do I remove it?
Turn the outside walls around that floor into gaps (select each one and tap its trash can, or set Type to Open), select one of the gaps and tap Remove area. The floor that goes is shown in red, anything standing on it is outlined in red, and the interior wall that should be the outside wall turns blue. Tap Delete (or Delete all) to confirm. Your rooms are kept and Undo reverses it in one step. If you see This area can't be cut off in a straight line, draw an interior wall where the outside wall should go and try again; if a wall beside the gap has a locked length, unlock it first.
How do I take off a room I added with Add Room?
Right after adding it, Undo. Later: select each of the room's outside walls and tap its trash can (three walls for a room on one side of the house), select one of the gaps and tap Remove area, check the red preview and tap Delete. The room's floor comes off, the wall it shared with the house becomes an outside wall again at the same thickness as the rest, and the windows on the rest of that house wall stay where they were.
Why don't I see Remove area?
It only shows on a selected gap that has floor behind it. A single straight gap (one deleted wall) has nothing behind it to remove; turn the walls around the corner into gaps too.
Does a gap show in exports and 3D?
A gap is an open side: no wall is drawn there on the plan, in 3D, or in your exports. The floor and the rooms behind it are unchanged.
Start designing your room
Put this into practice in the floor planner: draw it, furnish it, walk through it in 3D — on web, iOS, and Android.
Open RoomSketch3DOne-time purchase · No subscription · Web, iOS & Android