Have a towering oak or pecan shading your Brentwood yard? That tree is more than a landmark. It can cool your home, manage stormwater, and boost curb appeal, and it is protected by Austin’s tree rules. If you plan to buy, sell, remodel, or add hardscape, understanding those rules will save you stress, time, and money.
In this guide, you’ll learn what Austin counts as a Protected or Heritage tree, how to plan around the critical root zone, what permits you may need, and what mitigation could cost. You’ll also get practical steps for care and construction. Let’s dive in.
Why big trees matter in Brentwood
Mature trees provide shade, help cool your home, and support local habitat. Research often links mature trees to higher property appeal and potential value gains, though results vary by species and placement. Arbor Day Foundation summaries explain these benefits in plain language.
Austin takes urban trees seriously. City presentations highlight how tree protection is built into local development rules, which affects projects on Brentwood lots. You can review the policy context in this City of Austin tree regulation presentation.
Austin rules for big trees on your lot
What is a Protected or Heritage tree
- Protected tree: 19 inches diameter at breast height (DBH) or larger. Removal or impacts require City review.
- Heritage tree: certain species reach Heritage status at 24 inches DBH, with stricter limits and added process.
You can confirm definitions and the process on the City Arborist Program page.
How DBH is measured in Austin
Measure the trunk at 4.5 feet above ground. Multi-trunk trees use a specific City formula. If you are unsure, ask a professional to measure. The City outlines measurement details here: Trees on commercial and multifamily property.
Know the Critical Root Zone (CRZ)
The CRZ is a circle centered on the trunk. The radius in feet equals the trunk diameter in inches. A 20 inch tree has a 20 foot CRZ radius. The City’s standards require preserving at least 50 percent of the CRZ at natural grade and limit disturbance and heavy pruning. See the preservation criteria in the Environmental Criteria Manual (ECM) 3.3.2.
Permits, emergencies, and enforcement
Tree reviews are part of the building permit process, and separate reviews apply in some cases. Emergency removal for Dead, Diseased, or Imminent Hazard trees is possible, but the City must evaluate the tree. Unpermitted removal can lead to penalties. Start on the City Arborist Program page. For concerns or complaints, the City’s environmental inspectors provide guidance on the Environmental Inspections page.
Smart steps before you buy or list in Brentwood
- Order a tree inventory or survey. An ISA certified arborist can document species, DBH, condition, and the CRZ for each significant tree. The City may require a survey during permitting. See City survey expectations under tree reviews and permitting.
- Use practical contract protections. Ask for disclosures about prior tree permits or known health issues. Include a contingency to confirm whether planned work could trigger tree permits or mitigation.
- Gather records. Maintenance notes, pruning history, and any City permit files help buyers understand what is possible on the lot.
Plan construction around trees
- Design around the CRZ. Place additions, driveways, and utilities to preserve at least 50 percent of the CRZ at natural grade. If impacts are unavoidable, use alternatives like pier foundations or hand excavation described in ECM 3.3.2.
- Install protection fencing before work starts. City presentations show strong fencing and mulching standards for permitted sites. See examples in this intro to Austin’s tree regulations presentation.
- Limit pruning and avoid root cuts. Major crown removal or root damage can be treated as removal. Coordinate timing and methods with an arborist.
- Hire the right pros and keep records. Use an ISA arborist and follow the City’s inspection process. Keep plans, permits, and post construction care notes handy for inspectors and future buyers.
Care for mature trees year round
- Mulch wide, not deep. Keep mulch away from the trunk flare and extend outward as space allows.
- Water during drought and after construction. Slow, deep watering supports recovery.
- Follow any remedial care plan. For retained regulated trees that were impacted, the City may require ongoing care. New mitigation plantings typically need enhanced care for the first two years. See mitigation care expectations in ECM 3.5.4.
Considering removal? Know costs and alternatives
Start with City approval criteria. Removal of Protected or Heritage trees is limited and must meet specific findings. If removal is approved, you must mitigate by planting replacement caliper inches or paying into the Urban Forest Replenishment Fund. The ECM provides a standard conversion of one caliper inch to 200 dollars when payment in lieu is used, and Heritage trees often have higher mitigation percentages. Review details in ECM 3.5.4.
- Example: If a 20 inch Protected tree requires 100 percent mitigation and on site planting is not feasible, the payment in lieu could be about 4,000 dollars using the ECM’s standard conversion. Actual mitigation and fees are set by the City Arborist for each project.
- Learn how mitigation dollars support citywide planting through the Urban Forest Replenishment Fund overview.
Neighbor issues and quick contacts
- Overhanging branches. Texas law often allows trimming to the property line, but heavy pruning or root impacts can violate Austin rules for Protected or Heritage trees. When in doubt, consult the City Arborist Program or an ISA arborist before cutting.
- Suspected illegal removal. Report issues through 3 1 1. City environmental inspectors outline the process on the Environmental Inspections page.
Local resources
- City of Austin City Arborist Program: definitions, permits, and contacts. Tree reviews and permitting
- Environmental Criteria Manual: CRZ and preservation standards. ECM 3.3.2
- Environmental Criteria Manual: mitigation and payment in lieu. ECM 3.5.4
- City Environmental Inspections: reporting and inspections. Environmental Inspections
- Urban Forest Replenishment Fund: how mitigation supports planting. UFRF overview
Protecting big trees on your Brentwood lot keeps your property cooler and more inviting, and it helps you stay compliant with Austin’s rules. If you are planning a purchase, preparing to list, or mapping out a remodel around a mature oak or pecan, let’s build a plan that preserves your trees and your timeline.
Ready to talk about your goals in Brentwood? Reach out to Olivia Osborne for local guidance tailored to your home and project.
FAQs
What counts as a Protected or Heritage tree in Austin on a Brentwood lot?
- In Austin, trees 19 inches DBH and larger are Protected, and certain species at 24 inches DBH are Heritage with stricter limits and processes.
How do I calculate the Critical Root Zone for a large tree in Austin?
- The CRZ radius in feet equals the trunk diameter in inches, and at least 50 percent of that area should be preserved at natural grade when feasible.
Can I remove a hazardous large tree quickly in Brentwood?
- If the City determines a tree is Dead, Diseased, or an Imminent Hazard, removal can be expedited, but you still need City evaluation and the proper authorization.
How much could tree removal mitigation cost under Austin rules?
- If removal is approved, mitigation often equals replacement inches or a payment in lieu at roughly 200 dollars per caliper inch, with higher percentages for Heritage trees; City staff set final amounts case by case.
Who should I contact if I suspect illegal tree removal in Brentwood?
- Report concerns through 3 1 1 so the City’s environmental inspectors and City Arborist can investigate.
