Heritage trees are similar to protected trees, but are subject to much stricter regulations. In Texas, heritage trees must measure more than 24 inches in diameter. If you're looking to remove a heritage tree, you must first obtain a variation from the director of the Department of Developmental Services. Protected trees, on the other hand, can be removed without any variation under certain circumstances.
In Austin, some trees (such as oak trees) are more protected than others. If you need to remove a tree that is 8 inches in diameter or larger, you can do so without a city permit as long as it is not a protected tree. However, if the tree is damaged and removed within 7 days of the damage, and the tree causes an “imminent danger to life or property”, then you may be able to remove it without a permit. If you want to remove a tree of 8 or more, other than a protected or heritage tree, all you have to do is mark its removal on the site plan.
In certain situations where tree felling is authorized, the city will require mitigation measures, often by planting replacement trees. If a protected tree is dead or poses a hazard to people or property, you can remove it without a permit. When trees have multiple stems, if the diameter of the largest stem plus half of all other stems is two feet or more, it is also considered a heritage tree. Heritage trees larger than 24 inches, but smaller than 30 inches, require an administrative variation from the director of the Department of Developmental Services before removal.If you're thinking about building in Austin, it's important to have a good understanding of the city's tree rules to determine what can be built on lots with large trees.
The city offers workshops that provide guidance on how to apply for a tree permit and useful tips on tree care.