Do Westlake Village Oak Trees Need a Permit?

You are considering a Westlake Village home with oak trees, or preparing to sell one before a buyer starts planning a pool, addition or new paving. The trees may affect what work can be done and which City approval is required.

A protected oak cannot be altered, removed or damaged without approval unless a specific exemption applies. Even construction that never touches the trunk can count as damage when it enters the protected root area. This is general information and not legal advice.

The controlling rule is Chapter 9.21 of the Westlake Village Municipal Code, titled “Oak Tree and Heritage Tree Preservation Standards.” The chapter was reenacted by Ordinance No. 292-22 on June 8, 2022.

What counts as a protected tree?

A protected tree is either a designated heritage tree or an oak that meets the chapter’s size test.

An oak is any deciduous or evergreen tree in the oak genus, Quercus. It reaches protected status at 12.5 inches in circumference, equal to 4 inches in diameter, measured 4.5 feet above mean natural grade. For an oak with multiple trunks, the test is a combined circumference of at least 18 inches, equal to 6 inches in diameter, for any two trunks measured at the same height.

Do not assume that a tree is protected based on a photograph, listing description or casual measurement. An owner should have a qualified arborist measure it. Under the code, that means an arborist certified by the International Society of Arboriculture.

The City Council may also designate a heritage tree, including a tree that is not an oak, by resolution after a public hearing. The owner receives written notice by registered or certified mail at least 10 days before that hearing. The Director keeps the City’s heritage tree inventory, and the Council may later rescind a designation.

What work is allowed without a permit?

Routine maintenance and certain hazardous, dead or dying trees are exempt from the chapter’s permit requirements.

Routine maintenance includes removing deadwood and trimming live branches that are less than 4 inches in diameter at their widest point. The exemption limits how much canopy may be removed in one year. It never covers lion tailing cuts, topping cuts or cuts that leave branch stubs.

A protected tree is also exempt when a qualified arborist determines that it poses an imminent threat to life and property. Trees that a qualified arborist determines are dead or dying are exempt as well. Another exemption covers alteration or removal that the City Engineer deems necessary for private streets or public infrastructure.

Which tree work needs City approval?

Large pruning cuts and limited construction encroachments may qualify for staff approval, while removal generally goes to the City Council.

The Director may issue an Administrative Tree Permit without a public hearing for cuts to live branches over 4 inches in diameter when a qualified arborist determines that the work will not adversely affect the tree’s health. The same administrative process can cover encroachment into the protected zone when the arborist reaches that conclusion.

That zone is broader than the trunk. The code’s definition of damage includes paving, changing natural grade, trenching, excavating or building within 5 feet beyond the dripline or 15 feet from the trunk, whichever distance is greater. Cutting, nailing, burning, toxic substances and machinery that injure roots or other parts of a tree also count as damage.

The Director must approve an administrative request when the tree report establishes at least one listed basis. These include work needed to preserve the tree’s health, structure or balance, an encroachment that will not harm the tree, or cuts needed to protect existing development without harming the tree. The Director may deny the request or refer it to the Council. An appeal goes to the Council under Chapter 9.32.

Removal requests that do not satisfy an exemption require City Council approval through a public hearing with notice.

What must go into the application?

The owner or authorized representative must file the City’s form, the fee set by City Council resolution and a qualified arborist’s tree report. An alteration report must evaluate the tree’s health, document defects, explain each proposed cut and analyze its effect. A removal report must explain why removal is necessary. The City may obtain third-party arborist review at the applicant’s cost.

The City will not accept the same or substantially the same permit application within one year after final action. An approved permit also expires after its stated period, or after one year if none is stated, although the Director may grant an extension of up to one year for good cause when requested before expiration.

The November 4, 2026 Land Use Committee agenda lists an Administrative Tree Permit item together with planned development and sign modification permits for the same restaurant remodel. The project included encroachment into the protected zone of one oak tree. As of November 4, 2026, the outcome is unknown because the committee result was not reviewed.

How does the Council decide and what can it require?

The Council may approve a protected tree permit if alteration or removal cannot reasonably be avoided through redesign, is necessary for required public infrastructure, addresses a tree that has outgrown its space and is damaging or will damage pavement or structures, or addresses poor health or structure that makes failure foreseeable near structures or areas with high pedestrian traffic.

Removal or relocation is not permitted if it would cause soil erosion through diverted or increased surface water flow that cannot be satisfactorily mitigated.

The Council may require on-site replacement with suitable trees in an appropriate location, or off-site replacement when planting on the property is not feasible. Replacement trees should be at least 24-inch box size, with one to four new trees for each protected tree removed.

A protection or replanting plan may set fencing, equipment limits, corrective work and arborist supervision. It may include a bond guaranteeing replacement-tree survival for five years. If a replacement dies, a new tree and a restarted five-year period may be required. The Council may also require recorded CC&Rs or a deed restriction covering proper care, watering and maintenance.

What should a buyer or seller check?

A buyer or seller should identify the trees, their protected zones and any permit conditions before relying on a remodel concept.

Ask for available arborist reports and tree permit records. A buyer can also ask whether any recorded deed restriction, CC&Rs or other tree-care conditions affect the property. Chapter 9.21 does not state that a seller must disclose oak trees or that a permit automatically transfers with a sale, so those points should not be assumed from this rule.

Check any planned addition, pool, trench, driveway or paving against the protected zone, which is 5 feet beyond the dripline or 15 feet from the trunk, whichever is greater. Plans involving hillside walls and decks may also call for a review of the separate Westlake Village hillside wall rules. If an association is involved, the California HOA disclosure guide explains the broader document review. Nearby cities use different tree rules, as the Calabasas oak permit guide shows.

A Westlake Village homeowner wanted to remove an oak whose roots were lifting part of the patio. Because the tree stood inside his lot, he assumed he could schedule the work without contacting the city. We checked the permit requirements first and discussed whether pruning, treatment or another approved solution could address the damage.

What happens if a protected tree is damaged?

The Planning Department enforces Chapter 9.21 through code enforcement. The Director issues written notice requiring work to stop until the violation is corrected, and each protected tree damaged in violation is a separate offense.

Unauthorized damage may suspend concurrent development permit approvals until corrective measures are complete. The City can also require corrective work and, at the Council’s discretion, arborist reports, replacement planting, or donation of trees of reasonably equivalent size and value. These consequences are additional to penalties under Chapter 1.2, but no amount is stated here.

The Council may revoke a permit after a hearing for fraud, deceit, misrepresentation or failure to follow its conditions. Its decision is final.

The short version

Westlake Village protects designated heritage trees and oaks that meet its measurement test. Routine maintenance is limited, large pruning and protected-zone encroachment may qualify for an Administrative Tree Permit, and nonexempt removal requires City Council approval.

Before buying, selling or planning construction, have a qualified arborist measure the trees and locate the dripline and protected zone. Check City permit records and ask about recorded care conditions.

For another part of your property review, check the home value tool.