Grids and columns

What you'll do

Set out a building on a grid, then draw walls and place columns along its lines.

Place a whole grid

1. Turn on Draw, then choose Build › Grid.
2. Click Place a grid…. Say how many numbered lines (1, 2, 3…) and lettered lines (A, B, C…) you want and how far apart. Type one spacing, or several separated by commas for uneven bays (for example 20', 24', 20'). Past the last lines is how far each line runs beyond the outer lines of the other kind, and Turned (degrees) turns the whole grid.
3. Click Place it, then click where the first crossing (1 / A) goes. The preview follows the pointer.

Numbered lines run up the plan and are spaced across it; lettered lines run across the plan and are spaced up it. Letters skip I and O, as on drawings, so they are never read as 1 and 0.

Draw grid lines one by one

With Grid on, click where a line starts and where it ends. It gets the next label of the lines it runs along (after 3 comes 4; after B comes C). Press EscEsc to stop.

Change a grid line

With Grid on, click a line to pick it. Type a new Label and press ReturnEnter, or click Delete this line (or press fn DeleteDelete). Bubbles puts the bubbles at both ends, at the start or end of each line, or nowhere. Each change is one step: ⌘ZCtrl+Z takes it back.

Draw along the grid

The Wall tool, the Column tool and the other drawing tools snap to grid lines and to where they cross (the snap mark is a small circle with a cross).

Columns: choose Build › Column, pick the shape (rectangular or round), the size, and whether the column runs to the level above or to a fixed height, then click. At every grid crossing places a column at each crossing that has none yet. Click a column to change its shape, size or height in Properties; fn DeleteDelete removes it. Columns that run to the level above follow it when its height changes.

What you should see

• The grid on the plan of every level, with a bubble and its label at the ends of each line.
• Grid lines on the drawing set: on the plans, and on elevations and sections where a line is seen end on, with its bubble above the building. See Elevations, sections and sheets.
• In the IFC file: one grid for the building (IfcGrid, its numbered lines in one list and its lettered lines in the other), and columns as IfcColumn with their size, height and quantities. Other BIM programs show both.