You may occasionally need to work with a drawing that another architect, surveyor or landscape designer has developed. A example is shown in the figure below.
A design such as this is most likely to be delivered to you in AutoCAD dwg format. Not all drafters who produce CAD drawings in AutoCAD work in a tidy manner and as a first step, it is a good idea to check and tidy up the dwg file before beginning to work on it.
As a first step, open the drawing (in dwg format) and use the "Check AutoCAD drawing" option on the Tools drop down menu.
If the drawing is not capable of saving in dwg, you will receive the warning shown below.
Ignoring a message such as this can result in problems. Although you may be able to save the file in lcd format and work on it, it will not be possible to subsequently save a dwg copy of your work. The figure below shows that the AutoCAD symbol table is corrupt. Almost certainly, the error was present in the original dwg file.
Check list 1
When communicating with designers who send you dwg files:
1. Ask the designer to use the PURGE command in the AutoCAD environment before sending it to you. This command removes any unwanted blocks, layers, linetypes, text styles etc. It also dramatically reduces file size.
2. If the designer uses a CAD standard, ask for a copy. AutoCAD drafters vary in their use of text styles, colors, layers and linetypes. If they use a special linetype file or Windows fonts, ask for a copy.
3. Ask your supplier to make sure that they have used the AutoCAD's AUDIT command before sending on the drawing file. We have had instances where gCAD+ objects to a corrupt dwg file and gCAD+ gets the blame. Running the AUDIT command in AutoCAD and using the audited copy in gCAD+ fixed the problem. The AUDIT command can be run from the command area by typing audit and hitting the RETURN key. This ensures that the dwg file is in tip top condition before it comes to you.
Check list 2
Here is a check list for dealing with dwg [AutoCAD] drawings once you have obtained a clean copy from the designer.
1. Always work on a copy of the file.
Keep the incoming CAD base drawing as delivered to you in its unaltered state; work on a copy.
If your supplier has used any non standard windows or CAD fonts, ask them to send a copy with the dwg file.
2. Check drawing layers.
Use the layer icon and turn on all layers. In the figure below, you can see that many layers were turned off in the drawing as it was delivered. It is easy to miss important information on a layer that has been turned off, so turn them all on.
Although in the figure above, we have selected the "All used layers" link as turned on all layers, it is much better to highlight the "All" option and use the Visibility on option. In this example, this revealed many more layers that were part of the drawing but did not have anything on them - those layers contained no entities.
Here is a different drawing showing the huge number of empty layers in the drawing.
Remove those layers not containing entities.
Here is a movie showing how to show and remove layers not containing entities. Removing these empty layers can have a marked effect on file size. The figure below shows that there were 175 empty layers in this example!!
Save the file (as a dwg file) as this point, perhaps adding the phrase pass1 to the file name - e.g. the drawing might be called "IncomingDesignPass1.dwg". In this particular example, the dwg file size dropped from 893k to 333k - a huge reduction in file size.
Next, turn on all layers containing entities.
Right click on the "Layers with entities" option and turn visibility on. As shown below, turning on all layers is likely to reveal a considerable amount of additional information. We see lots of overlapping text entities in the legends to the right. These legends are best moved to their own location such that there is no overlap. That is best done once a check has been made that each entity in the drawing is on its appropriate layer (see below).
Make a small list of remaining layers and check the contents of each, making notes about the content of each as you go. Here is the table from this particular example:
Vivavces (perennials) [The designer has created a separate layer for perennials - layer when we use the Layer States Manager, that layer will be combined with other layers in a group perhaps called planting]
Arbres&Arbustres (Trees and Shrubs) [The designer does not seem to have set the canopy diameter appropriate for the expected size of the plant]
Arrosage (Irrigation) [one point - perhaps a supply point needs attention. Some lines have line thickness, other not]
Cotation plans (Dimensioned plan) [Check the dimension style used - adjust text height, arrowhead size etc. if necessary. This layer needs to be combined with a Layer manager state perhaps called Construction when the drawing is eventually turned into a gCAD+ drawing]
Cotation plantation (Planting spacing dimensions) 
Cotations jardins (Garden dimensions) [Combine layer with Planting group]
Coupe' A-A1 (section) [There is no section line present]
Fond de Plan (Base Plan) [One dimension incorrectly placed on this layer]
Legend [conations a reference to retaining wall [Murs soutènement]
Massif bis (new construction - cyan) 
Massif four (more new construction - cyan)
Massif quart (more new construction ? - magenta)
Point zero (setout point) [needs some values for construction team - move drawing to convenient setout point]
Electricitie (lighting) 
Check Zoom Extents
At this point, it is a good idea to see if Zoom Extents operates correctly. In this particular drawing, using zoom extents made the drawing disappear (left two tiny dots at the edge of the screen). These dots were very difficult to see. Zooming in on the entities at top left of the screen showed that they were copies of entities placed "way off from their proper location". That's why the zoom extents option did not show the whole drawing as had been expected. Once those entities had been removed, the drawing behaved normally.
Zooming in on the errant group of entities showed some lines, and block on various layers. We erased these unwanted entities.
Zoom Extents then behaved as expected.
Layers and entities
It is not uncommon to find entities on the wrong layer. In this instance, several entities were placed on a non printing (Defpoints) layer as shown in the figure below.
Tip: The layer name Defpoints comes from the use of AutoCAD applications. Any entity placed on that defpoints layer will not print.
To clean things up, the Defpoints layer was made current and all other layers turned of (with a right click on the "All layers with entities" item and selecting Visibility on. All entities on the Defpoints layer were moved to layer zero.
It is a good idea to work through and check the contents of each layer. In the figure below, we look at the layer arrosage (watering). Because the legend for this layer overlaps with another legend, it was moved away from the clash. The legend is better in its own floating viewport on the same layout page as the irrigation layout (in another floating viewport) - see later.
Another thing to watch is the number of layers that may be present in the incoming drawing that have no right to be there - drawings from civil survey firms are an prime example, they often contain lots of unwanted (empty) layers. Make a double check to ensure that you have removed all of these. Removing these unwanted layers can have a marked effect on file size.
It is a good idea to save and reopen the drawing again (still in dwg format) at this point to make sure that all unused blocks have been removed.
Hatch. The properties box is most useful here. Just select any hatching in the drawing. If the hatching does not have a recognized pattern with it, delete it. It is quite easy to reapply hatching using gCADPlus tool. The figure below shows that some of the hatching in the drawing is not in fact hatching at all, but an un-named block (H10).
Remove any hatching that does not conform to the proper hatch pattern name. Be especially careful of Custom hatching - it is often at the wrong angle. the figure below shows some hatching at an odd angle - we strongly suggest removing all hatching and reapply later in the gCADPlus/lcd file environment later. Save the drawing again - still in dwg. At this stage we had reduced the size to 238 Kb.
Tip: If you come across this problem of Custom hatch patterns or hatching as blocks in your own work with gCADPlus, make sure that you uncheck the tick box in the plug-in option under Tools (shown below)
This particular drawing contained lots of examples of this type of hatching. these were removed, further reducing file size.
Text. Use format and check on styles. Clearly some very strange styles are contained in the drawing. A style called S4 here has so small a height setting, it would be difficult to see ant lettering made using that style.
Here is another example. the designer supplying the dwg file has used a Windows font that we do not have in our system.
Leave style standard with the font Simplex. In addition, once we have cleaned up the dwg file and saved it as a lcd (gCAD+ file), we are in the habit of setting CityBlueprint as our default style because its use give the design a hand drawn look.
It is worth checking the type of text entity being used. In this case, MTEXT has been used for single pieces of text where a simple text entity would be much better.
Here is another example of this.
Dimensions. Use Dimension>Style to check on the dimension style loaded with the drawing. In this example, two styles were in operation, each with different precision. We suggest creating your own dimension style (when you finally save a gCAD+ file) setting a dimension layer as current and applying a test dimension.
Dimensions should be applied in model space. Set the text height and arrow head size appropriate.
Here is another example from a different job. The dimension style here is clearly not suitable for work in the metric environment as text height is far too small.
5. Ensure units format is appropriate
Use Format>units and make sure that units are set to decimal (not in surveyor's units - distance and bearing) and angles are measured anticlockwise. in this case, they had been left in surveyor's format.
6. Check area statements
If values have been written for areas, use the AREA tool to check them. Do not assume that the previous designer has measured areas accurately. The figure below shows that the stated garden bed area is incorrect. It should read 3.5 m square.
7. Check for entity duplication
Make sure that there is no duplication of entities. The figure below shows that two different arc are used to define a corner garden bed. Only one can be correct. Eliminate any incorrect duplication such as this.
7. Check base units
Find a known distance in the drawing to determine if a full size and accurate model has been created. The figure below shows that the drawing in in meters. Since everything in the building (landscape construction) trade is in mm as the base unit, there is a need to scale the drawing.
In this case, the simplest approach is to select those parts of the base drawing that we need to work on, copy those to the clipboard, start a new drawing, paste the copied entities and scale by 1000.
8. Re-scale the drawing so everything is in mm
The drawing needs to be scaled by 1000. Provided that you have removed all of the hatching in the incoming drawing, it is a simple matter to select everything in model space and scale by 1000 with a base point of 0,0.
You may need to adjust the dimension styles at this point. They need to be set with larger arrowhead and text heights to match the new space. A value of 150 is a good starting point for values.
9. Add a scale bar (and north point)
Now would be a good time to trim off the overhanging horizontal site boundary line.
10. Save as a gCAD+ File
Finally it is time to save the drawing as a gCAD+ drawing. In this example, the drawing was further reduced in file size to 122 kB. This is a massive reduction in file size and produces a drawing that is very easy to work on and very responsive.
11. Set up layout sheets
Now is a good time to test for appropriate paper size and scales. The two figures below show the effect of trying two different paper sizes (A4 and A3) each with a fixed scale of 1/100. Clearly, the A3 sheet is an appropriate size. The inclusion of the scale bar certainly assists the presentation.
The drawing is now in a state that we can put our own stamp on the design. The plant symbol library can be used with symbols coming into the drawing editor at the correct size, as are details, we have a custom text style, we can add our own hatch pattens an line types, a custom dimensioning style is set and we have chosen an appropriate sheet size and scale to work with.
Importantly, the file size has been reduced from >800 kB to 122 kB and there is no danger of strange hidden entities causing grief for gCAD+.
It is now (finally) time to work on the design. Although it is not always feasible, it may have been much simpler and less time consuming to have measured the site ourselves. We load a plant list suitable for Parisian gardens and start work.