Look up a municipality's tree-protection-zone (TPZ) ordinance before construction work

Steps

1. Search the specific municipality's code (often hosted on Municode, American Legal, or the city's own site) for 'tree protection,' 'tree preservation,' or 'urban forestry' ordinance chapters.
2. Identify the DBH (diameter at breast height) or height threshold that triggers 'protected tree'/TPZ status in that jurisdiction — thresholds vary widely by city (an 8-inch DBH is a common but not universal example).
3. Determine how the TPZ boundary is measured locally — commonly the drip line, though some cities instead use a fixed radius scaled to inches of DBH.
4. Contact the city arborist, urban forestry office, or planning/development services department before construction to confirm whether a tree protection plan or permit must be approved prior to grading, clearing, or fencing.
5. Do not begin work inside a TPZ without the enforcement officer's or city arborist's written approval, submitting a plan showing critical-root-zone protection measures if work must occur inside the zone.