Build Floor Roof

Build Floor Roof

Floors and roofs from the closed regions between lines.

Point it at the linework already in your project — a CAD plan imported or linked, detail and model lines, room and space separation lines, area boundaries, property lines, filled regions, zones, rooms, spaces, areas, existing slabs, wall centre lines — and it finds every closed region between the curves, however untidily they were drawn. Lines may cross, overshoot, stop a hair short of each other or lie on top of one another. Each region is shown in a drawing inside the window and becomes a floor, a roof, or nothing; regions can be combined; curved edges can be kept, fitted with arcs, or broken into straight segments by a rule you choose. One press of Build makes them all, and one Undo in Revit takes the whole run back.

When to use it

• A consultant's CAD plan is linked into the project and every slab edge has to be traced by hand — with gaps and overshoots that stop Revit's own sketch from closing.
• A building has dozens of rooms or balconies that each need their own floor finish, and the room separation lines or room outlines are already there.
• A roof should follow the footprint of a floor that already exists, or the outline of a parcel.
• Curved façades whose edges must be built as true arcs for setting out, or as straight segments to suit a panel or formwork module.
• Cleaning up CAD layers before building: draw chosen layers as Revit lines, and remove lines drawn on top of one another.

How to use

1. Open Build Floor Roof from BimCode's plugin list inside Revit, with the plan view that shows your outlines active.
2. Tick the kinds of lines to read under Sources on the left, then press Read lines. The drawing appears in the middle with every closed region filled in and numbered.
3. Click a region and choose Floor, Roof or Skip in the bar above the drawing. Ctrl-click or Shift-click to set several at once; Combine makes several regions one element.
4. Pick the floor type and roof type on the right. Open Placement if they belong on another level or need an edge offset.
5. Press Build. The floors and roofs appear in Revit and the regions turn green. Anything Revit refused is listed with the reason, and Save report writes a spreadsheet of everything that was made.

Nothing in the model changes before you press Build — everything up to then is a preview, and what the drawing shows is exactly the outline Revit receives.

The tabs

• Build — sources and region rules on the left, the drawing in the middle, the regions, types, placement and the Build button on the right.
• Tools — draw chosen CAD layers as Revit detail or model lines, and find or remove lines drawn on top of one another.
• Setups — save the current settings under a name, apply, rename, export to a file for a colleague, import theirs.
• Help — the full manual, searchable.

Good to know

• Gap tolerance decides which line ends count as touching. Start small (1 mm) and raise it until the regions you can see are found; small crimson circles in the drawing mark the line ends that meet nothing.
• Nested outlines — a shaft in a slab, a courtyard in a block — can be built both, left as a hole, or filled in. Each region can still be set by hand afterwards.
• Sloped roofs pitch from every outer edge at the angle you give. A shape Revit cannot resolve into slopes is built flat rather than lost, and the result says so.
• Neighbouring regions always share exactly the same edge, so two floors built side by side meet with no sliver and no overlap.
• Setups are kept in your Windows profile, not in the project, and sizes are stored in millimetres and square metres, so a setup means the same in a metric or an imperial project.
• It works in projects, not in the family editor. Very large CAD drawings are read up to 160,000 curves; for bigger ones, select the part you need.

The step-by-step guide is in docs/USER-GUIDE.md; notes for whoever changes the plugin are in docs/DEVELOPMENT.md.