Floors, roofs, stairs and components

Floors, roofs, stairs and railings are drawn in sketch mode: their lines are sketched first, and the element is made only when the sketch is finished. Components (furniture and plumbing fixtures) are placed with a click. Curtain walls are described in Walls, doors and windows.

Sketch mode

Home ▸ Build ▸ Flooring, Roof, Stairs and Railing open sketch mode. The contextual tab is named after what is sketched (Edit | Create Floor Boundary, Create Roof Footprint, Create Stairs Sketch, Create Railing Path) and has:

• the Mode panel: Finish Edit Mode makes the element; Cancel Edit Mode drops the sketch and leaves the model as it was;
• the Draw panel, with the drawing tools of the element;
• for stairs and railings, the Tools panel.

Nothing is made while sketching: the lines are magenta, and the model changes only with Finish Edit Mode. The whole element is then one step of the undo history: one Ctrl+Z takes it away.

Drawing lines

Offset on the options bar moves the drawn lines (and the lines of picked walls) by that distance.

Floors and roofs need closed loops. A loop drawn inside the outer one is an opening: the floor or the roof has a hole there. When Finish Edit Mode finds lines that do not close or that cross, a message says so and the sketch stays open to be fixed (Continue).

Picking and changing sketch lines

Esc ends the chain being drawn; a second Esc puts the drawing tool down (so does Modify). While the sketch is open its lines are elements of the view, and Modify works on them as on other lines; nothing else can be picked until the sketch is finished:

• the line under the cursor is highlighted; a click selects it, Ctrl adds lines, Shift takes them away, a window selects several, Tab the chain of joined lines;
• the ends of the selected lines drag, and the ends joined there follow; a dragged line takes the lines joined to it along;
• Move, Copy, Rotate, Mirror - Draw Axis, Array, Align, Offset, Trim/Extend to Corner and Split Element work on them, and the sketch stays open;
• one selected line shows temporary dimensions to the nearest parallel line on each side (another sketch line, the wall's original outline, a wall, a grid, a level): click the value and type a distance to move the line; the symbol beside it makes a permanent dimension, kept while the sketch is open;
• its properties are in the Properties palette: Defines Slope and Slope, for a roof line picked from a wall its Overhang, and its Length.

Align takes as its reference the line under the cursor, and Tab goes to the next one there, so a sketch line can be aligned to a wall's layer or core boundary. While drawing or dragging an end, the points snap to the corners of the walls' faces, layers and core boundaries, then onto those lines. Del deletes the selected lines. Ctrl+Z while sketching takes back the last change to the sketch, not to the model. All this works in plans, in sections and elevations (a wall's profile) and, for selecting, dragging ends and deleting, in the 3D view.

Editing the sketch of an element

Select a floor, a roof, a stair or a railing: the Mode panel of its contextual tab has Edit Boundary (floors), Edit Footprint (roofs), Edit Sketch (stairs) or Edit Path (railings). Sketch mode opens with the element's lines, openings, slopes and arrow; Finish Edit Mode changes the same element, Cancel Edit Mode leaves it unchanged.

The sketch opens with Modify active: its lines can be selected and changed at once.

In a plan the sketch is drawn on the level; in the 3D view it lies on the element's own plane (the floor's top, the roof's base) and the 3D view stays open.

A new floor can be sketched in the 3D view too: Flooring started there puts the sketch on the plane of the level, the line being drawn follows the cursor with its length, and Finish Edit Mode makes the floor without leaving the 3D view. In the 3D view the options bar's Level chooses the work plane: the level whose plane the sketch lies on and the floor goes on. Pick Walls takes the wall whose face is under the cursor. Roofs by footprint, stairs and railings are sketched in a plan.

Floors

1. Click Home ▸ Build ▸ Flooring. Sketch mode starts with Pick Walls.
2. Click the walls around the floor, or press Tab over one of them and click to pick them all. Each line goes on the interior face of its wall; the lines of walls that meet are trimmed or extended to meet at the corner.
3. Or draw the boundary with Line or Rectangle; draw a loop inside it for an opening.
4. Click Finish Edit Mode.

On the options bar, Extend into wall (to core) puts picked lines into the wall up to the face of its core, and Offset moves them (a negative offset moves them away from the walls). The type of the new floor is the one in the type selector at the top of Properties.

Sloped floors

A floor slopes in one direction, set in one of two ways while sketching:

• a Slope Arrow: its properties are Specify (Height at Tail, from the heights of its two ends, or Slope), Height Offset at Tail, Height Offset at Head and Slope. The heights are measured from the top of the floor;
• one boundary line with Defines Slope ticked and its Slope in degrees: the floor rises from that line, inwards.

The floor is sloped in 3D and in sections. Its Slope Angle in Properties changes the slope afterwards.

Floors over walls

When a floor crosses walls (an upper floor resting on the walls below, for instance), its slab is cut out of them: in 3D and in sections the wall stops under the floor and goes on above it, and walls go on through the floor's openings.

Floor properties

Type Properties has the floor's Structure (its layers) and its default thickness.

Roofs

1. Click Home ▸ Build ▸ Roof. Sketch mode starts with Pick Walls; the options bar has Defines Slope, Overhang and Extend into wall (to core).
2. Pick the walls (Tab for the whole chain). Each line goes on the exterior face of its wall, moved out by the overhang (from the face of the core with Extend into wall (to core)).
3. Or draw the footprint with Line or Rectangle; a loop inside is an opening.
4. Click Finish Edit Mode.

Every line with Defines Slope rises inwards at its Slope (30° by default); a small triangle with the slope is drawn beside it. The shape comes from those lines:

• all the lines define the slope: a hip roof;
• two opposite lines do not: a gable roof, the walls under the gables rise to the ridge when attached;
• no line defines the slope: a flat roof, or a roof sloping along a Slope Arrow (then no line may define a slope).

To change one line, press Esc twice, click the line and change Defines Roof Slope, Slope or (lines picked from walls) Overhang in Properties.

Select walls, click Modify Wall ▸ Attach Top/Base, then the roof: they rise to its underside, gables included (Walls, doors and windows tells more).

Roof properties

In plan a roof shows its outline, ridges and hips; in 3D its slopes, overhangs and layers.

Stairs

1. Click Home ▸ Circulation ▸ Stairs. Sketch mode starts with Run.
2. Click where the first riser is, then where the run ends: the run snaps to whole treads, and the status bar counts the risers made and left (for example 9 risers created, 8 remaining).
3. To turn, click again away from the end of the first run and draw the next one: a landing joins them.
4. When every riser is placed, click Finish Edit Mode.

The Width on the options bar is that of the new stair (by default the type's). Tools ▸ Railing Type chooses the railings of the new stair: a railing type, put on both sides, or None.

The number of risers comes from the height between Base Level and Top Level (with their offsets) and the type's Maximum Riser Height; changing a level or an offset in Properties changes the risers. Edit Sketch reopens the runs: delete a run (click it, Del) and draw it again; the railings of the stair follow.

In plan the stair shows its treads up to the cut line, the break line, the arrow and the UP/DN text; in 3D its treads and risers, or a monolithic slab, its landings and railings.

How a stair is built

Type Properties of the stair decide its construction:

• Monolithic Stairs ticked: each run is a concrete slab cut to the steps; its underside runs parallel to the slope, Structural Depth below the inner corners of the steps, and the landings are as thick: the sloping underside of a run meets the landing's underside along a line, without a step; each run ends with its last tread: the landing, flush with it, or the floor above makes the last riser, so steps and slab show as one solid with no line across the risers.
• otherwise treads (Tread Thickness) with risers (Riser Type Straight, Riser Thickness) or open (None), on stringers: Right Stringer and Left Stringer Closed (a board the treads are housed in), Open (a board cut to the steps, the treads on top) or None, and Middle Stringers under the treads, with their Stringer Thickness and Stringer Height.

The landing stops behind the last riser of the run that reaches it, following its back face; in a monolithic stair it starts at the riser's face. At the top the run's underside goes on under the floor of the top level until it meets the floor's underside, as under a landing.

A section across the stair shows it cut with its slab. Volume in Properties and in the schedule of stairs is the volume of its solids.

Railings

1. Click Home ▸ Circulation ▸ Railing.
2. Draw the path with Line: one chain of connected lines (a path in pieces is refused at Finish Edit Mode).
3. To put the railing on a stair, click Tools ▸ Pick New Host and then the stair: the path drawn on it climbs with the stair.
4. Click Finish Edit Mode.

Edit Path reopens the path of a railing. The railing's Type Properties has its Railing Height and Baluster Spacing: changing them changes every railing of that type.

The railings of a stair run on over its landings as one rail, at their height above the line of the nosings and above the landings. Where a run leaves a landing one riser higher, the type's Tangent Joins (the rail goes straight on) and Angled Joins (it turns) decide the join: Extend Rails to Meet (tangent joins only) carries the sloping rail on down to the landing, Add Vertical/Horizontal Segments rises upright at the first riser, No Connector leaves a gap.

The rails are mitred at every joint, where the path turns and where the slope changes: with Rail Connections Weld each rail is one piece, with Trim its pieces are cut on the joint's vertical plane. A post stands at the start and the end of each railing and at every change of direction in plan (none where only the slope changes). Use Landing Height Adjustment with Landing Height Adjustment raises (or lowers) the rail over the landings by that much.

Components

1. Click Home ▸ Build ▸ Component. The type selector lists the components loaded in the project; a preview follows the cursor, in plan and in the 3D view.
2. Press Space to turn the preview by 90°.
3. Click to place the component on the level of the plan.

Mode ▸ Load Family opens the library, by folder (Furniture, Plumbing Fixtures): choose a family and click Open to add its types to the project.

Select a component and click Host ▸ Pick New Host, then a floor: the component moves onto the floor and stays on its top (click an empty point to put it back on the level). Its properties are Level, Host, Offset from Level, Rotation, Mark and Comments; Type Properties has its width, depth, height and material.

Schedules and IFC

Floors, roofs, stairs, railings and furniture have their schedules (View ▸ Create ▸ Schedules ▸ Schedule/Quantities), one row per element. Export ▸ Export IFC4… writes floors as slabs (with their openings and slopes), roofs, stairs with their flights and landings, railings, furniture and plumbing fixtures.

Not yet in BIMopen

Ceilings, ramps, roofs by extrusion, shafts and vertical openings, slab edges, fascias, gutters and soffits, stairs sketched by boundary and riser lines, spiral stairs, and arcs in sketches come after this chapter's realignment.