Thanks for your response. I have tried to use rasters, but the editing window for the rasters are too small (only 8x8 pixels), so the dashes shown on screen, print or in .pdf format are too short/small. If
Delmer, I am not sure I understand what you mean by filling the wall with an ?image?, but if you mean for example a raster, I believe you have the limitations I have described above.
Brendan, your suggestion is a good method visually, but it is of course more laborious to edit. I figure that the wall tool would be a more elegant and labour-saving method. If only the hatches could stay inside the wall edges! Maybe this is the way the program works, as indicated by Delmer.
Yesterday I installed a plug-in called ?Broken line?. With this tool you can fill in text or symbols in the space between the line. I found out that if you use a filled rectangle, it is possible to edit the line (space width, number of breaks, line color/thickness (?none?), to get the line you want, more or less. It seems that you are limited to a line though, you cannot apply the plug-in on a polyline or a wall tool. If you extend the line, the number of breaks stay the same, and you have to adjust the number of breaks accordingly.
Any clever Vector-script editors out there?