Landscape designers commonly work with architectural drawings as a base for their design work. These drawings can take many digital forms - AutoCAD dwg or DXF files, DXF files from a variety of other CAD software and scanned drawings of hand drawn or computer plotted prints. It is best to chase these digital files whenever you can; load into gCAD+ and away you go. However, there are time when all you have are copies of paper drawings.

This paper provides some advice on how to handle paper drawings in the gCADPlus environment.

Working from scanned drawings

While not as convenient as working with DXF or dwg, it is possible to work with a scanned copy of an architects drawing. The figure below shows an example of what you might receive from an architect.

Scanned drawing

We suggest that you use the Draw>Insert Raster tool and insert a copy of this scanned image into the gCADPlus environment. It is useful to insert the image at a scale of 1.0 (taking the scale image at insertion option off) because if the original scanning has been done carefully, there may not be much need to re-scale the image to match the dimensions of the 'real world'.

Note that not only can the option to scale the image on entry be turned off, it is also possible to change the resolution of the scanned image at insertion. A resolution of 150 dpi rather than the 300 dpi shown below should be ample to allow accurate copying. The figure below shows the setting we used to insert the scanned image of the drawing above.

Scaling

Once the scanned image has been placed, we find it convenient to turn off the Properties box so as to have more screen real estate. It is also a good idea to select the image and use the tools drop down to make sure that the image is at the back. Any new lines we draw in the copy process will show clearly (and can be easily selected for editing. In addition, we like to move the image file onto its own layer so it can be turned off later (rather than deleting it).

Paste image

Finally, the drawing color is to red (use the color toolbar item to do that) and begin to trace over the 'substance' of the drawing. 

Place line

We continue to trace over the important features of the base plan. In the figure below, we have adjusted the thickness of the line to make it more obvious. Because we are copying (tracing) there is a danger that entities may not quite reflect the true circumstances. For example, the boundary line is not quite vertical (as it should be). We will edit the angle of the line at a later stage to make sure that it is vertical (and that the house walls are also square).

plce architect drawing

The architectural drawing showed the position of some existing trees. While it was not necessary, we made a new symbol to match the scanned tree symbol. One copy has been placed at the side of the scanned drawing for ease of viewing.

Paste image

The image below shows the final result (still with the image showing).

final

Now that the image no longer displayed (layer off), we square up entities using the properties box. In this drawing, most entities should have an angle of 0, 90, 180, 270 degrees. With sufficient skill and foresight, it may have been possible to use Polar settings to archive that during the copy process.

Square up

Next we check scaling. The front boundary is 13 meters (13000 mm) wide. it reads 13398.52 so the CAD drawing needs to be scaled by 13000/13398.52 = 0.9702. The figure below shows that we now have an accurate model to work with. How much easier would it have been if the architect could have been persuaded to part with a CAD version of his drawing.

Accurate scale

Now it is a simple matter to work on our design. Because the model is full size, the symbols from our library can be placed properly. We decided to emphasize the 45 degree roof angle by reflecting it into the front garden (and use bands of 45 degree planting) to create a secluded sitting area.

 Front garden

And part of the (unfinished) design in layout space.

front garden

and the rear garden design (based in part on a design by Lisa Orgler [http://lunchboxproject.blogspot.com.au/2013/05/design-with-me-pick-theme.html])

The 45 degree angle is further emphasized. Click on the image to see a PDF version of the drawing. No text or plant schedule has yet been applied.

rear garden

 

Trace architects drawings