A site logistics plan from a drone scan is built in a fixed order: fly the site before mobilisation, turn the imagery into a scaled orthomosaic and model, measure the real boundaries and constraints off that model, then draw the laydown, crane, access, welfare and waste zones on top at 1:1. The capture does not design the plan. It removes the two things that make site plans wrong, an out-of-date base drawing and dimensions nobody checked. Re-fly at each phase change and the plan keeps matching the ground.
What the Plan Has to Answer
Write the decisions down before you book a flight, because the capture has to show the evidence for each one. Five answers, five zones on one drawing:
- Where material lands, and how it reaches the work face.
- Where the crane stands, what it swings over, and who is kept out of that arc.
- How a concrete truck or a skip lorry gets in, turns and leaves without reversing blind.
- Where people park, eat and change, and how they walk in.
- What cannot be touched: retained structures, trees, services, the neighbour's boundary.
Three inputs produce it: an aerial capture of the whole site, a ground-level capture of what the aircraft reads badly, and the drawing set. Plans fail most often because the first is missing and zones are drawn onto a boundary surveyed two years ago.
Step 1: Capture at the Right Moments
The baseline flight is the important one, and it happens before mobilisation. Fly the site as found: boundaries, levels, kerb lines, service covers, trees, adjacent roads and a margin beyond the hoarding. Once the first excavator arrives, the ground you planned to use for laydown is the ground being dug up, and there is no way to re-capture what was there.
After that, fly when the site changes shape rather than on a calendar.
- Groundworks, after cut and fill: platform levels, excavation edges, the haul route as built.
- Frame, at each slab: structure against boundary, crane positions, overhead obstructions.
- Change, any move of entrance, crane or compound: the compound as occupied and the routes in use.
Each pass invalidates the zone areas you calculated off the last one, which is the point of taking it.
The flight is a separate step from the processing, planned and flown in whatever app the aircraft came with; under Part 107 the ceiling is 400 feet above ground, though a site plan usually flies lower for resolution. Plan oblique passes as well as the straight-down grid, because a nadir-only flight flattens stockpiles, retaining walls and excavation sides, which are what you measure volumes and clearances from.
Some parts of the site the aircraft cannot read: the inside of a building you are keeping, a gate under a canopy, the width between two posts. That is where a phone capture earns its place. Walk those areas with Polycam in Space mode and you get a measured ground-level model at the same detail, in the time it takes to walk it. The job site scanning patterns guide covers the walk itself; aerial and ground capture are two halves of one base. If the compound has no signal, check which survey apps work offline first.
Step 2: Turn the Capture Into a Measured Base
Processing gives two products that do different jobs. The orthomosaic is a top-down image of the site at a known scale, and it is the base the layout is drawn on. The 3D model is where you check what a flat image hides: clearance under a canopy, the height of a spoil heap, the sight line from a cab to a turning point.
Upload the imagery somewhere that will reconstruct it into a measurable model. In Polycam that is Object mode, from the phone or, for a full grid flight, from the browser, where the published range runs from 20 to 1,000 images. The drone processing comparison covers which app suits which site. Polycam does not fly the aircraft; it works from the media, so flight planning stays in the drone's own app.
Check scale before you draw a single zone. Pick a dimension you can verify on the ground, such as gate post spacing or a marked bay, and measure it in the model. If it disagrees with the tape beyond your tolerance, rescale now. A base a few percent short moves every zone edge, and a crane base that looked clear ends up inside its own swing.
Fix the origin and orientation at the same time. Agree where zero is and which way is grid north, and write both on the sheet, because the ground team sets zones out from there. Where real-world coordinates are required, georeference with ground control points in CloudCompare or QGIS after export; otherwise a local system aligned to the setting-out grid is enough.
Step 3: Measure the Constraints First
Constraints first, zones second. The zones that survive are drawn into the space left over, not drawn first and trimmed later.
- Gates. Clear opening between posts, not the nominal width, plus the swing of the leaf and the turning envelope of the largest vehicle.
- Routes. Width between what actually narrows them, usually a stockpile rather than the kerb.
- Radii and gradients. Measure the turn off the model and check it against the vehicle's turning circle; verify any ramp a loaded lorry climbs.
- Overhead. Lines, canopy, scaffold, the underside of a loading bay, with height and owner recorded.
- Below ground. Covers, chambers and drainage runs in the ortho, and soft spots that show up after rain.
- Boundaries. Offset from the hoarding, root protection areas, structures that stay.
Measure point to point on the model rather than scaling off a printout, and check anything the plan leans on from two features. The site survey workflow walks the full capture-to-CAD sequence if you need it end to end. Photogrammetry holds a working tolerance at site scale, not a millimetre, so tape the dimensions that carry risk: a gate width deciding whether an abnormal load enters is worth two minutes with a tape.
The crane needs its own treatment, because the swing circle is not a fixed offset. It comes from the machine's tail swing radius, which changes with configuration, so check the plan against the actual crane and its load chart. OSHA 1926.1424 requires control lines, warning lines, railings or similar barriers to mark the boundaries of swing radius hazard areas. The sheet therefore needs two lines, the swing circle and the barrier outside it, both dimensioned.
Step 4: Draw the Zones in Sequence
Draw access first, then crane, then laydown, then welfare and waste. Reverse that order and you get a compound with nowhere for a lorry to turn.
| Zone | What decides where it goes | What to measure off the capture | What goes wrong |
|---|---|---|---|
| Entrance and gateline | Distance from the highway, sight lines, gate swing | Clear opening between posts, swing arc, sight line both ways | Sized to a van, then blocked by the first delivery |
| Access and haul route | Fewest reversals from gate to work face | Narrowest point, turn radii, gradient, overhead clearance | A route a loaded lorry cannot follow |
| Crane and swing exclusion | Pick coverage, ground bearing, tail swing | Swing radius against the real machine, distance to boundary | Drawn on the plan, never marked on the ground |
| Laydown and storage | Proximity to the work face, lifting points, weather | Usable area after the working offset, teleporter access | Never checked against the volume it must hold |
| Waste and skips | Collection access without entering the compound | Distance from the gate, turning space for the lorry | The lorry reaches them, nobody can walk past |
| Welfare and canteen | Walk from the work face, services, privacy | Floor area needed, door swing, level ground | Placed last, in the worst space left |
Give each zone an area figure from the area tool rather than leaving someone to estimate it. A laydown zone that looks generous on an A3 is often a third of the packs you need once the working offset, turning space and pedestrian route come out. Pick one working offset for zone edges and hold it, because an offset that changes per zone reads as an accident.
Step 5: Put It on the Drawing Set and Keep It Current
Bring the orthomosaic into CAD as a reference underlay at scale, then draw on named layers: access, crane, laydown, welfare, waste, exclusion. Lock the underlay and keep it as a separate file. Then check it against the project drawing: where the CAD boundary and the captured boundary disagree, the capture is current and the drawing is not, so settle that before the logistics sheet is issued.
Issue one sheet per phase rather than one sheet revised forever. The layout that works at frame is wrong at fit-out, and a sheet that tries to cover both ends up with zones in the wrong places for most of the job.
The sheet has to carry its provenance: capture date, model reference, origin and north, scale, revision and approver. A logistics plan without a capture date is a drawing of a site that no longer exists, which is the fastest way to lose a ground team's trust.
Keep it current on two triggers: a schedule, and any change of shape, whether that is the crane, the compound, the entrance or a handover. Overlay the new ortho on the last one and the difference is your change list, including the route that has worn wider than drawn and the zone that has crept into the exclusion. Reissue, and take the superseded sheet off the gate, because two revisions on one hoarding means people read the wrong one.
Step 6: Hand It to the Ground Team
A PDF in a project folder is not a logistics plan. The version that works is on the gate, in the cabin and in the induction.
- One A3 at the gate and one in the office, laminated, current revision only.
- Zones in the same colours as the CAD layers, dimensions written on rather than scaled off.
- Setting-out dimensions from a point that exists on the ground: gate post, boundary corner, chamber cover.
- A name and number for whoever owns the plan, and the rule for changing it.
Mark the zones physically in the week they are drawn, with paint or cones set out from the dimensions rather than by eye. When drawing and ground disagree, the ground wins and the drawing becomes decoration. Brief it in the induction walk: each subcontractor needs their zone, their route and where they are not allowed to stand.
Keep the channel open the other way. The ground team will find what the capture could not, from a soft spot that swallows a telehandler to a neighbour's gate that opens across your route. Give them somewhere to put it and add it to the next revision. A shared model link helps, because a foreman can open the 3D on a phone and see what is behind the stockpile without walking out to look.
That is the loop: capture, measure, draw, hand over, re-capture. The flight is a short task at the start of each phase, and it is the reason the plan on the gate still matches the site behind it.
FAQ
How do I build a site logistics plan from a drone scan?
Fly the site before mobilisation, process the imagery into a scaled orthomosaic and 3D model, then measure the boundaries and constraints in that model. Draw the access, crane, laydown, welfare and waste zones on the model at 1:1, and issue the sheet to the team that has to work to it.
When should I capture the site for a logistics plan?
Before mobilisation, because the ground you want for laydown is the ground the first excavator arrives to dig up. Re-fly at every change of shape: after groundworks, after the frame, and whenever the crane, entrance or compound moves.
Can I measure laydown areas and crane exclusion zones off drone imagery?
Yes. A reconstructed model has distance and area tools, which are enough to check a gate opening, a haul route width or the footprint of a laydown zone. Any dimension the plan depends on for safety should also be taped on site.
How accurate is a drone scan for a logistics layout?
Good enough for zone edges, route widths and area checks, not for setting out. Photogrammetry at site scale is not millimetre work, so treat small differences as noise and verify the critical dimensions, such as a gate that decides whether an abnormal load enters, with a tape.
Does Polycam fly the drone?
No. Flight planning and capture happen in the drone's own app, and Polycam processes the images or video you upload into a model you can measure, annotate and share. On the web, the published range is 20 to 1,000 images per upload.
How often should a site logistics plan be updated?
On a schedule and at every phase change. Overlay the newest capture on the previous one to see what moved, reissue with a new revision, and take the superseded sheet off the gate.
