Tree ordinances · Metro Atlanta · Read against the ordinance text
Deck and addition footings inside a protected tree's root zone.
A conventional footing means digging inside the soil a tree ordinance exists to protect, which is what triggers the review, the encroachment cap and the no-disturbance radius. A ground screw is driven rather than dug. Below is what each metro Atlanta city actually requires, taken from its own ordinance, and where a driven footing changes the answer.
Told no because of a tree?
Tree & critical-root-zone rules across metro Atlanta, city by city.
Digging a conventional footing means altering the soil inside a tree's critical root zone (CRZ), which is exactly what a city's tree ordinance is written to stop. A driven ground screw doesn't require that excavation, so it's often the more direct path back to a permitted project. The rule is different in every city. Here is what we have confirmed against the ordinance text itself, starting with Decatur.
- A Tree Conservation Plan is required with any Land Disturbance or Building Permit application for work that could disturb, remove, or alter soils within a protected tree's critical root zone (CRZ).
- Encroachment beyond 20% of the CRZ is prohibited without an approved arborist prescription.
- No land disturbance is permitted within 10 feet of a protected tree's trunk.
- A pre-application conference with the City Arborist is required before submitting a Tree Conservation Plan or a permit application affecting a CRZ (treepermits@decaturga.com).
This is a summary for orientation, not legal or arborist advice — the City Arborist's determination on your specific site and tree governs.
Why a driven screw is often a shorter path
A conventional footing means digging and pouring inside the soil the ordinance is built to protect — which is exactly what triggers the Tree Conservation Plan review, the 20% cap, and the 10-foot no-disturbance zone. A galvanized ground screw is driven, not dug: it displaces a fraction of the soil a footing hole does, and doesn't require the excavation the ordinance is written around.
That doesn't bypass the City Arborist's review — it changes what the review is looking at. Bring us the tree, the plan, and the arborist's notes; we'll tell you plainly whether a driven footing is the fit.
Decatur is where we are based, not the limit of where the rule matters. Four more metro cities have their own tree-protection ordinance, each read against its own text, below. Tell us where the site is and we will work from the rule that governs it.
The rest of metro Atlanta
Where a city's formula differs from Decatur's, the difference is stated.
| City | What the ordinance says |
|---|---|
| City of Atlanta | Code of Ordinances, Ch. 158, Art. II (rewritten by legislation 24-O-1691, effective 2026-01-01): CRZ formula confirmed unchanged by the rewrite — 1 ft radius per inch DBH, adjustable by the City Arborist for documented site conditions; >20% CRZ grade-change counts as "destroy." |
| Sandy Springs | Development Code, Art. 9, §9.3 (Environmental Protection): CRZ = the tree's drip line or 1.25 ft per inch DBH, whichever is greater, to a depth of 3 ft. A Tree Removal Permit is required whenever a Protected (≥18" DBH), Setback, Boundary (≥10" DBH on an adjacent lot), or Landmark tree is removed, or 25% or more of its CRZ is disturbed — whichever comes first. |
| Brookhaven | Code of Ordinances, Ch. 14, Art. III, §14-50/14-52: CRZ = a circle with radius equal to 1.3 ft per inch DBH (the ordinance's own example: a 20-inch tree's CRZ radius is 26 ft). At least 80% of the CRZ must stay undisturbed on a protected tree; a Boundary Tree Agreement is required once proposed CRZ impact reaches 20%; excavating, compacting, or disturbing soil in the CRZ is barred outright, "regardless of the existence or lack of an approved site plan," and can trigger a stop-work order. |
| Avondale Estates | Code of Ordinances, Ch. 5, Art. X ("Residential and Commercial Tree Protection and Preservation"): CRZ = 1 ft radius per inch DBH, the same formula as Decatur and Atlanta (the ordinance's own example: a 20-inch tree's CRZ is 20 ft). A tree removal permit is required to remove a protected tree, or when land disturbance would encroach more than 20% of a protected tree's CRZ; a boundary tree is one with 20% or more of its CRZ crossing onto an adjacent lot. |
Outside metro Atlanta the same reasoning applies, with a local rule in place of these. We install and supply across Georgia; tell us where the site is and we will work from the rule that governs it.
Send us the site, including the tree.
Plans, a sketch, the arborist's notes, or a few site photos are enough for a first-pass answer. Straight answer either way, including when a driven footing is not the fit.