Structure: Columns, Beams, Gridlines, Braces and Footings

The structure tools

**Gridline** (`GRIDLINE`, `GL`): click both ends; keep going for the next. Type `GRIDLINE 4 6000` and press Enter to array four more 6 m apart from the selected one.

**Column** (`COLUMN`, `CL`): opens the column presets; the next click stands one, and it snaps to a room corner.

**Grid columns** (`GRIDCOLUMNS`, `GC`) and **grid beams** (`GRIDBEAMS`, `GB`): fill the gridlines' crossings with the armed column, and their lines with beams.

**Beam** (`BEAM`, `BM`): click one support, then the other; keep clicking to carry on.

**Brace** (`BRACE`, `BR`): click where it starts at the floor, then where it ends at the head.

**Pad footing** (`PADFOOTING`, `PAD`): click where its centre goes, under a post or a pier with no column.

**Shell** (`SHELL`, `VAULT`): a barrel, groin or cloister vault over a rectangle.

Columns

A column is designed in its panel: what it is **Made of**, a **Section preset** or its own **Width** and **Depth**, its **Height**, and its **Head**: a fixed height, the underside of the beam it carries, or the ceiling of the room it stands in.

Shaft, base and capital each have their own options: taper, entasis, flutes, drums, a plinth pier, anchor bolts, a capital with bracket arms.

A column has a pad footing under it on its own, merged with any pad it overlaps.

Beams and braces

**Section**: rectangular, I, box or channel, with its width, depth, flange and web, or a preset.

**Where it hangs**: the **Drop** below the floor above, and what each end **Lands on** (a wall top, a wall face, a column top, a column face or nothing) with its **Bearing length**.

**Derived**: the clear span and the set out length are worked out and shown.

A brace has its own section and its heights at each end; its diagonal length is shown.

Footings

Settings › Structure › **Foundation** switches strip footings on for the whole building. Off until you ask: a footing is concrete nobody ordered.

Set the **Soil bearing**, and the strip's width and depth are worked out from it, or type your own. A raft, a sill plate and the bar schedule are in the same place.

A single wall or pad can differ in its own panel, or have **No footing**.

Tip: the sizes are worked out from a soil number you type, with no ground investigation behind them. They are a starting point for an engineer, not a design.

Generate a frame

Settings › Structure › **Generate** makes a frame for inspiration: how many storeys, what footprint area, which shape, concrete or steel. Columns on a grid, beams along it, a slab a storey, braces on a steel frame.

Or an **A-frame** from its numbers: a deck, a roof down to it, two gable ends and a loft on each storey above.

Generating again replaces the last one; what you drew on it stays. **Modify** changes the last frame in bulk: its spans, material, sections, braces and storey height.

Read next

• Walls and rooms
• Roofs
• Import and export
• Checks and issues

Frequently asked questions