AutoCAD Tip – Use Draw path option for Hatch Creation on Site or Survey Drawings

by Dennis Collin

My origins of using AutoCAD started with me producing site or survey drawings of areas due for development. When producing plans of that type/scale buildings are typically represented by a simple perimeter line which has some shading applied to the interior to denote the area of a building.  (Fig 1)

The shading needs to fall inside the boundary line so that the overall boundary extents is not obscured by the colouring in. which is why the use of polyline widths or line weights are not the correct approach as they can obscure the real position of the true building exterior corners.

When I performed such tasks 30 years ago, we used a LISP routine to do this, in fact this is still a possible answer, however now in the 21^st Century we do have some other options!

Fig 1. Using a custom linestyle to denote building extents.

On a previous post here, I used a custom line style to produce a series of diagonal lines to indicate building extents. This is a fair method, but problems can arise if annotative scale is used with the MSLTSCALE variable enabled.

With the release of AutoCAD full and LT 2025 it is now possible to create such hatching in without having to draw and interior and exterior boundary, but inside create the hatch in a draw mode, very similar to the creation process of a line.

Fig 2a. Note AutoCAD’s additional command line options for hatch patterns.

Execute the hatch command choose the draw option (Fig 2a). Then set the hatch mode to path option to denote the fill creation option.

Fig 2b. Setting Path mode for hatch object creation.

Then choose the following options

• Alignment – Exterior
• Width – 1000 mm
• Settings – Ansi 31 Hatch Pattern Style (or similar)
• Scale – 200 (depending on drawing units and extents)

The value of the width does depend on the nature of drawing and units used, if in doubt make it the same size as text or another annotation on the drawing.

Fig 3. The finished result!

If necessary, the Match Properties command can be used to ensure that these new shaded areas have been applied consistently throughout the drawing.