Issue description
You want to create a fill Pattern to accurately represent aspects of your project, but you also need it to work with the different scales used.
Solution
1. Set the scale to 1:1
2. Draw the fill at true size using the line, circle, or polyline tool
3. Copy the pattern and go to the Options > Element Attributes > Fills.
4. Select New.
5. Select Symbol type > Name the line type.
6. Select Paste > to copy Pattern over.
Now we need to edit the stroke values for the horizontal, vertical and offset:
1. Edit the values until the pattern you drew starts to take shape.
2. Select Scale with Plan (Model Size) to make the fill scalable.
3. Select OK.