Guide
How to do a tree survey for a development site
Every tree protection plan starts with a survey. Get the field work right and the rest is quick. Get it sloppy and you pay for it twice, at the desk and back on site.
A tree survey is the field work that everything else leans on. Call it a tree inventory if you like: the point is to find every regulated tree on the site, measure it, judge its condition, and record exactly where it stands. Do that well and the protection plan almost writes itself. Do it in a hurry, on a paper form you will decipher later, and you have signed up for a second trip.
Here is what to capture and how to run the survey so the data holds up in review and moves cleanly into the plan.
The record
What to capture for every tree
- A unique ID and tag. One number per tree, matched to a physical tag you can find again.
- Species. Common and botanical name. Species drives the root-zone rules and often the protection status.
- DBH. Trunk diameter at 4.5 feet. This one number feeds the root zone and the mitigation count, so measure it carefully.
- Condition. Good, fair, poor, or dead, plus a line on why. Reviewers read the why.
- Structural notes. Defects, deadwood, codominant stems, lean, anything that changes the risk picture.
- Location and a photo. A GPS point and at least one image, so the tree is provable long after the leaves are down.
- Protection status. Flag protected, specimen, heritage, or landmark trees. They carry stricter rules and bigger mitigation.
In the field
Running the survey, step by step
- 1
Get the tree list and walk the site first
Before you tag a single tree, walk the whole parcel. You want a feel for how many trees you are dealing with, where the clusters are, and what the terrain does to your GPS. If the civil team already has a boundary or a topo, load it. Ten minutes of walking saves you an hour of backtracking.
- 2
Tag and number every regulated tree
Give each tree a permanent ID and hang a numbered tag you can find again. Sequence matters less than consistency: whatever numbering you use in the field has to match the report and the plan later, or you will spend the evening reconciling tag 47 against three different lists.
- 3
Measure DBH the same way every time
Diameter at breast height means 4.5 feet up the trunk. On a slope, measure from the high side. Fork below breast height? Most ordinances want it measured as two stems, or the larger. Pick the rule your jurisdiction uses and hold to it, because DBH is what drives the root zone and the mitigation math.
- 4
Rate condition and note the structure
Good, fair, poor, dead: that is the usual scale, but write down why. A codominant stem with included bark, a big deadwood limb over the sidewalk, a lean that started last storm. Those notes are what turn a raw inventory into an arborist report a reviewer trusts.
- 5
Capture an accurate location and a photo
Drop a GPS point on each tree and take at least one photo. Under a heavy canopy your phone GPS will wander, so this is where an external receiver (Bad Elf, Garmin, a survey-grade unit) earns its keep. The photo is your proof six months later when someone asks why tree 112 came out.
- 6
QC before you leave the site
Do a quick pass while your boots are still muddy. Missing DBH, a tree with no photo, two trees sharing a tag: all of it is a two-minute fix on site and a return trip if you catch it at the desk. Finish the survey where the trees are.
Do it once
Collect in a form that flows to the plan
The trap is collecting on paper or a generic form, then retyping it. Capture it once, in a format the plan can read.
ArborCode
Built for this exact survey: voice entry, a photo on every tree, and your external GPS, working offline under canopy. The same collection then exports the CAD file and the report, so you never retype it.
See ArborCode →CanopyCode
Once the data is in AutoCAD or Civil 3D, CanopyCode turns it into the plan: root zones, impact analysis, labels, and tables. The survey is the input; this is the output.
See CanopyCode →Questions
Tree survey FAQ
What is the difference between a tree survey and a tree inventory?
In practice, not much, and people use the words interchangeably. A tree survey usually stresses the located, measured field work; a tree inventory stresses the resulting list of trees and their attributes. Either way it is the same job: find every regulated tree, measure it, assess it, and pin it to a coordinate.
What do I need to record for each tree?
At minimum: a unique ID or tag, species, DBH, a condition rating, a location, and a photo. Most jurisdictions also want you to flag protected, specimen, heritage, or landmark trees, since those carry stricter rules. Anything structural worth noting (defects, deadwood, lean) goes in too.
Do I need survey-grade GPS?
It depends on the reviewer and the canopy. Consumer phone GPS is fine on open sites; under dense canopy it drifts enough to matter, so an external receiver helps. Some jurisdictions want survey-grade accuracy tied to the site survey. Ask before you spend a day collecting points you have to redo.
How does the survey become a tree protection plan?
The inventory is the raw material. From there you draw each tree and its root zone, overlay the grading, decide what stays and goes, and produce the plan sheet and report. If your survey data is clean and in a format that flows to CAD, that next part is fast. See how to make a tree protection plan.