Cut an opening straight through a floor
Drag a rectangle to punch a void straight through a floor — for a duct, a plumbing run, or a shaft — and see it read cleanly through to the floor below in 3D.
Real buildings aren't sealed slabs: ducts, plumbing stacks, and utility shafts run straight through floors. The Floor Hole tool punches exactly that — a clean void through the floor slab, drawn as a rectangle you drag out and tune. It reads through to the floor below in 3D, furniture is kept clear of it, and its area is taken out of your square-footage totals.
The opening lives on the floor you draw it on — so on a multi-story design you'll usually cut it on an upper floor and look down through it to the room below. Nothing's placed permanently until you tap Finalize, so you can size and reposition freely first.
What you'll need
- •A floor plan with at least one room
- •Best shown on a multi-floor design — the opening reads through to the floor below in 3D
Step by step
- 1
Pick the Floor Hole tool
Build Panel → Floor Hole (the dashed-square tile, next to Vaulted Ceiling). The tile highlights and a banner appears: Drag a rectangle to punch a floor hole. On a multi-floor design, switch to the floor you want the opening on first.
Build Panel → Floor Hole — the banner prompts you to drag a rectangle. - 2
Drag out the opening
Drag a rectangle on the plan where the shaft goes. It becomes an adjustable draft — a dashed ring with a translucent fill and a handle at each corner. The draft turns red if any part of it strays outside the room, so you can see before committing why it wouldn't be accepted.
The draft ring with corner handles — nothing's committed yet. - 3
Tune it, then Finalize
Drag any corner handle to resize, or drag the body to slide the whole opening into place (openings can't be smaller than 12 inches on a side). When it's right, tap Finalize to commit it — or Discard to drop the draft. A hole that isn't fully inside the room, or that overlaps another, is refused with a note.
Finalize commits the opening; Discard drops it. - 4
See it read through in 3D
Switch to 3D. On a multi-floor design the opening cuts clean through the slab, so you look down through the upper floor to the room below — exactly how a duct chase or utility shaft reads on site.
The opening reads clean through to the floor below in 3D. - 5
Edit or remove it later
Tap a committed opening to select it — drag its corners or body to reshape it, or use the Delete control to remove it. Its area stays out of the room's gross and usable square footage the whole time it's there.
Tips
Line the shaft up floor to floor
A duct or plumbing run passes through every level it serves. Cut the opening in the same spot on each floor it crosses — switch floors and drag a matching rectangle — so the shaft lines up top to bottom.
Pair it with a staircase opening
A stairwell needs the floor above cut open so you can climb through it. Staircases handle their own floor opening, but the Floor Hole tool is the way to punch a standalone shaft that no staircase covers.
Common mistakes
Drawing past the walls
The draft turns red and Finalize refuses it when any part sits outside the room — an opening has to be fully inside the floor. Pull the straying corner back in until the ring goes normal again.
Leaving furniture over the shaft
Smart Flow Check flags any piece sitting over an opening (“…sits over a floor opening”) — the void runs clean through, so nothing can stand on it. Move the piece off the shaft to clear the warning.
Frequently asked questions
Does the opening change my square footage?
Yes — a punched opening is real floor removed, so its area comes out of both the gross (poured footprint) and usable (walkable) totals for that room.
Can I move or resize an opening after I finalize it?
Yes. Tap the committed opening to select it, then drag its corners to resize or drag the body to move it. Delete removes it entirely.
Do I need more than one floor to use this?
No — you can punch an opening on a single floor. But the read-through effect only shows when there's a floor below to see into, so it's most useful on a multi-story design.
What's the smallest opening I can cut?
Openings are held to at least 12 inches on each side, so a resize won't let you shrink one below a usable duct or pipe size.
Start designing your room
Draw it, furnish it, walk through it in 3D — on web, iOS, and Android.
Open RoomSketch3DOne-time purchase · No subscription · Web, iOS & Android