University of Vermont
Historic Preservation Program
HP 206 Researching Historic Structures and Sites
Here are some tips for HighDesign CAD software that is on the Macintosh computers in the lab. A trial version of HighDesign is also available from Ilexsoft on the web. Some of the features are similar to those of other CAD applications, however this software has special features that facilitate the documentation of existing buildings and it is written for Macintosh computers. When you first launch the application, it may ask if you want to update the software, just ignore this and proceed to the software already installed. (Software cannot be changed on the lab Macs so to protect them from viruses, et cetera.)
HighDesign tends to act weirdly if too many applications are running, so be sure to quit all applications and reboot the computer before you start.
To get things to work properly with HighDesign, the first step is to set the paper size and scales. When you start a drawing, specify the size of the drawing based on the paper sheet size you want. Under File, choose Page setup. For 11 by 17 paper choose paper size: tabloid and then select the proper orientation. The normal convention is to put north at the top. Under the File top pull-down menu, select Sheet size. Click on display page extent and under the System pull-down menu, select ASME and choose B for an 11 by 17 inch sheet. For an architectural drawing on 24 by 36 inch paper these page setup and sheet size settings should be changed.
Then set the scale that is appropriate to your task. (In the pull-down menu, Drawing - Change Drawing Scale.)
For site plans use an engineering scale (1” = 100’ ).
For architectural drawings use an architectural scale (1/4” = 1 foot) or 1/8” = 1 foot.
To determine the appropriate scale, first estimate the maximum length and width of the area you will be drawing and select a scale that will allow that area to be covered in your drawing, leaving room for margins. (There is more discussion on selecting scales for drawings in your textbook.)
Next, set the Drawing options under the Drawing pull down menu.
Click on the Drawing icon. Under Graphics, pen weight, select Actual weight (to see the thickness of the lines you are drawing.) You may also want to adjust the snap range and smoothing adjustments later. For architectural drawings it is best to use a bolder line weight for hard edges and a thinner line weight for soft or minor edges.
Then click on the Grid icon. If the default grid value is too high, then it may not be possible to select points with sufficient accuracy. So enter a low number (like 1) next to the blue squares for height and width.
Also in the Drawing options menu, adjust the Units. First click on the Units icon. For an architectural drawing, select fractional feet and inches, or decimal feet and inches and precision 2 (.01).
For a site plan, in the Drawing units pull-down, select decimal feet, then in the Precision pull-down, select 0 (1.). Now distance will be measured in whole feet.
Now to use the Photogrammetry tool:
For a house elevation, you will use a digital photo and actual field measurements. For this, the vertical calibration measurement might be the height of a door and for the horizontal it might be the width of a window or width of the foundation.
Warning: huge image files seem to bog down HighDesign, so adjust the size and scale of the background image first in Photoshop before importing with the Photogrammetry tool. (Try to keep the images under 4 MB.)
Under the Tools pull-down menu, select Photogrammetry. First it will ask you to select an image file for the photogrammetry background. After you have selected it, choose the type of geometry that seems best. (For a flat scanned map, select the one on the right that shows the house looking straight on.) Click OK and the background image will appear. A pop-up Photogrammetry setup menu will also appear that will ask you to calibrate the vertical and horizontal dimensions. To do this, click in the line icon on the left menu, click and drag the known distance over the photo image, then click on the arrow icon in the left menu to select that line, then enter the value in the pop-up menu.
When complete, HighDesign will automatically add a new drawing sheet in a pop-up window. You may have to adjust the scale and sliders on the photogrammetry sheet at 100% to see what you are projecting there as you trace features against the background map image. First trace the streets with the line tool. Click at the insertion point and drag with mouse down to the end point.
For curved lines, you can trace them with the freehand line tool. Click at the insertion point and drag carefully to follow the curved shape. I find it is best to do this in a series of short segments so that if there is a mistake, less needs to be undone.
Start with the major edges of your building elevation and the ground line. Then fill in features. The irregular polygon tool may work well for some features, like window openings and window sash. This tool may be a bit quirky to use a first. Here is how it works: First click on its icon at the left, then move the cursor to the point where you want to start drawing the shape. Click down on the mouse and hold it down to drag a line along one edge that you want to trace. Then release the mouse and move the cursor (without dragging) to the next spot (you will see a “spider thread” always stretching back to the starting point), click the mouse to set that third point and continue around the shape of the footprint to the point you started, then double-click to finish. Try it a few times. If it still won’t let go, try a triple click! (Undo is -z).
When you have traced all the lines that you want to draw, then select Exit photogrammetry under the tools menu. The background image will disappear, just showing what you traced. Now you can hatch/fill areas if needed. To set this up, double-click on the shaded irregular polygon icon on the left. Click on the Fill box and adjust the sliders beneath to get the color (or black) that you want. Click OK. Now choose the arrow icon on the left menu and click on one of the polygon footprints that you want to fill to select it. Under the tools pull-down menu select hatch selection. It should fill with the color you chose. If not, try selecting it again (be sure to click on one of the edge lines).
For rectangles drawn with the line tool, it will be necessary to convert the lines into a polygon before filling. To do this, all the lines must intersect.
Then select each of the lines with the arrow icon, holding down the shift key until they are all selected (dots will appear at the ends of the lines as you do this). Then under the tools pull-down menu, choose Convert to polygon. Then under that same menu, choose hatch selection and the fill should appear. If you get an error on this, probably some of the lines did not intersect, so you may need to shift them slightly by selecting them with the arrow icon and dragging the end point a bit until it closes.
To add text, choose the T icon and drag it to the right to create a text box. Then type in the words. By double-clicking on the T icon, you can change the fonts and sizes in text options.
My hope is that you all can pick up the basic skills for using CAD as a documentation tool. Since it is new software it will take some trial and error learning, but I hope that the learning curve is reasonable for everyone. You might make the best progress by allotting a few hours in the computer lab and following the steps I have outlined above. Be sure to include a text block that includes your name, the building name and address, the date of the drawing and an approximate scale.
It is possible to export your drawing as an image document that could be published on the web. First export in tiff format to your zoo account. Then open that .tiff file in Photoshop and make any size adjustments necessary and save as in jpg format for publishing on the web. (Saving directly to jpg sometimes messes up the drawing.)
Let me know when you have questions or if you make some discoveries that will help everyone in the class.