The park is 26 acres outside Indianapolis, built in 1974 for light manufacturing. Three metal buildings, a shared truck court, and a lot of cracked concrete. The new owner wants last-mile logistics: more dock doors, a bigger truck court, and a detention pond that the original site never needed. I rebuilt the site model from almost nothing, and it turned into a useful example of where each tool earns its place.
Stage 0: What I actually had
• A 1979 site plan, scanned, with a coordinate grid that does not match anything current.
• County aerial imagery from 2023.
• A survey of the front 300 feet, done for a road widening.
• No utility drawings worth the paper.
That is a normal starting point. The goal was not a perfect model. It was a model good enough to test trucks, drainage, and building size without waiting for a full survey.
Stage 1: Base map from OpenStreetMap
I pulled the area through CADMapper and got the street grid, building footprints, and property lines into a drawing within a minute. The footprints matched the aerial closely enough to use for area calculations. The property lines did not match the 1979 plan, which was the first useful thing the model told me: the shared truck court is probably not on the parcel the owner thinks it is.
What broke: OpenStreetMap had no fences, no dock positions, and no rear lot line behind the north building. I added those by hand from the aerial before going further. If you skip this, every setback calculation is fiction.
Stage 2: Ground and water in Civil 3D
I built a surface from the road-widening survey, the aerial contours, and about 80 spot shots I took with a hand level. The result showed the site draining to a ditch on the east side that disappears under a neighbor's gravel yard. The new detention requirement meant I had to prove where that water goes now, not where the 1979 plan said it went.
What broke: the scanned plan's spot elevations were in a different datum. I caught it because the building floor came out 3 feet above the road, which was wrong by exactly the amount of a known benchmark error. I shifted the points and rebuilt the surface. Always check one known elevation before you trust a whole scan.
Stage 3: Massing the addition
The owner wanted to know how much warehouse could fit on the north side without moving the shared truck court. I selected the open area in GenAnywhere and generated building volumes inside it, then moved the box until the truck court stayed clear. The tool filled the selection edge to edge, so I redrew the boundary 15 feet inside the fence and reran it. A 60,000-square-foot box fit with room for a fire lane. At 75,000 it did not.
That comparison took about 20 minutes. Drawing both options by hand would have taken a day and would have been less accurate.
Stage 4: Trucks and fire access in Site3D
A 53-foot trailer needs a 60-foot radius and a dock approach that does not cross a pedestrian path. I built the truck court geometry in Site3D and ran sweeps for a trailer, a fire engine, and a garbage truck. The trailer could enter but could not leave the far dock without backing across the lot. Moving the dock doors 8 feet north fixed it. The fire engine needed a wider gate at the east entrance, which also fixed a sight-distance problem at the street.
What broke: my first court had a 12 percent cross slope at the dock apron. The sweep did not care, but the drainage model did. I flattened the apron and added a trench drain.
Stage 5: Context with PlaceMaker
The last question was whether the expanded building would block the neighbor's loading area. PlaceMaker gave me the surrounding industrial buildings as massing, which was enough to see the shadow and the sight lines from the shared drive. It also showed that the park's only other exit is through a residential street, which is why the fire access fix mattered more than the owner thought.
What I took away
Five stages, five different failure modes. The base map lied about the property line, the scan lied about the datum, the massing filled the fence line, the truck swept fine but drained wrong, and the context showed an exit that nobody had mentioned. None of these were design problems. They were information problems, and the pipeline surfaced them in the right order.
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