Creating lattice under a deck or porch is easy to accomplish in Chief Architect using polyline solids with a lattice material applied.
To create lattice under a deck
In floor plan view, select Build> Primitive> Polyline Solid .
If you are drawing lattice under a staircase attached to a deck, then you will want to create that polyline solid in a Cross Section/Elevation view, so that you can reshape it to match the underside of the stair.
Resize and reshape the polyline solid as desired, based on the deck railings.
For the purposes of this example, make the Polyline Solid approximately 1/2" wide, and aligned underneath the deck railings above.
Note:If you are drawing the polyline solid on the Floor below the actual railing defining the Deck room, then you may find it helpful to turn on the Reference Display.
With the polyline solid still selected, click on the Open Object edit tool to display the Polyline Solid Specification dialog.
On the General panel, set the Elevation at Top and Thickness.
On the Fill Style panel, set a fill style, if desired.
For the purposes of this example, use an Angle Cross Hatch light brown in color, to more easily see the polyline solid's display in the 2D floor plan view.
On the Materials panel, set the material that you would like to use.
For the purposes of this example, use the Lattice - Diagonal material located in the Wire and Lattice Materials bonus catalog and blend it with an off-white color.
Now you can Copy and Paste the polyline solid, or repeat this process to add any other additional polyline solids with a lattice, chicken wire, chain link, mesh or other similar materials.