As indicated in SMMC 27.71.040#(a) and SMMC 23.40.020#(m), Existing trees/Major Vegetation means live vegetation, consisting of tree growth with a trunk diameter of 6 inches or greater measured at 54 inches above natural grade.
Existing Trees/Major Vegetation are required to be protected or replaced if removed for projects different from single-family requiring a planning application approval. See SMMC 27.71.150 Preservation of Existing Trees for more information.

No. Depending on the scope of the project, other requirements may apply. Single-family projects (Planning applications or Building permits) are usually subject to Chapter 13.40 only. However, multifamily, commercial, and/or large development projects are generally subject to Chapter 27.71 Landscape For Planning Applications, and/or Chapter 23.40 Site Development Code when applying for a planning application.

Trees provide important environmental benefits (e.g. trees improve air quality, conserve energy, reduce storm runoff, sequester carbon, etc.). When mature and established trees are removed, many of those benefits are lost. In the City, Protected Trees must be maintained and preserved in a state of good health, structure, and form (SMMC 13.40.070). Furthermore, during construction, Protected Trees are required to be protected with fences and other barriers to prevent tree damage that may result in tree loss, property damage, or even personal injuries.

No. City staff can only provide over-the-counter code consultation regarding development projects concerning trees. All Protected trees should be inspected and assessed by a private Certified Arborist at the project expense. The City Arborist will only review the proposed tree protection plans and approve the plan if consistent with the code requirements.

Is a professional who has demonstrated basic knowledge to inspect trees and perform tree care, obtaining a voluntary certification from the International Society of Arboriculture (ISA). Certified arborists provide consulting services in several areas of the Tree care industry. For assistance in locating a Certified Arborist, use the ISA Find an Arborist tool and the American Society of Consulting Arborists (ASCA) website.

The Project Arborist is an ISA Certified Arborist designated to evaluate the potential impacts of construction activities on Protected Trees and write specifications for tree preservation. A Project Arborist must be familiar with current industry standards and best management practices related to tree protection during construction.

For Protected trees, protection measures are required when construction activities are proposed within 10 times their trunk size (Tree Protection Zone). Construction activities as indicated in SMMC 13.40.030#(g) include all related activities which may or may not be shown on site plans, this includes storing or staging of materials, site access, parking, placement of temporary structures, debris disposal, additional excavation, landscaping, etc.
For trees not considered protected, protection measures are recommended and highly encouraged. When trees are retained on a construction site without necessary protection, the likelihood of their long-term survival is often very low.

Penalties for damaging any protected tree incurred during construction may include:
 - Penalties of up to $10,000 per participant per tree for such illegal acts.
 - A stop-work order until a mitigation plan can be prepared and implemented.
 - Replacement of each tree damaged or removed.
 - Any other penalties indicated in the Code and/or conditions of approval for the project.

Measure the trunk diameter at 54” above grade and multiply it by 10. For trees with more than one stem (arising at or below 54 inches) the trunk size shall be measured at the smallest diameter point below the main union of all stems unless the union occurs below grade, in which case each stem shall be measured as a stand-alone tree. For oak trees, if one stem is ten inches or more in diameter, the tree will constitute one Heritage Tree. For all other species, if one stem is fifteen inches or more in diameter, the tree will constitute one Heritage Tree. Use the Tree Diameter Measurement Guide to measure the trunk diameter of any tree.

An Arborist Report will be required when construction activities are proposed within 10 times the trunk size of any Protected Tree, including trees on neighboring properties or the right of way. The arborist report shall contain specific recommendations for protection during all phases of the project, in other words, a Tree Protection Plan (TPP). If the Project is proposing the removal of any Protected Trees instead, the Arborist Report must include all information that demonstrates that such tree (s) cannot be accommodated and saved during the project and the removal is the only option. The Arborist report shall explicitly recommend the removal of Protected trees referencing at least one of the findings/criteria outlined in the SMMC 13.40.100.

No, but they come together. An arborist report is a more comprehensive document that includes a survey and assessment of trees to be affected by construction. On the other hand, a TPP is a specific section within the Arborist report that contains recommendations for tree protection during the project.
An Arborist report may not contain a tree protection plan, but the tree protection plan always comes with the Arborist Report.

The Arborist Report should be submitted in a "Booklet" style when the assignment is somewhat complex and requires substantial detail (as recommended in the Consultant’s Guide to Writing Effective Reports by ASCA 2004). Like a book, booklet reports have a title page, table of contents, introduction, main text, glossary, bibliography, and supporting materials. Standard components of a booklet report include: A separate cover letter

 - Title page
 - Table of contents
 - Summary
 - Introduction, including the Assignment and Background
 - Observations
 - Analysis or testing
 - Discussion
 - Conclusions
 - Recommendations
 - Supporting material, including an appendix, glossary, bibliography, signature page, and statement of assumptions and limitations.

Yes, you must obtain a permit before removing Protected Trees. For removals related to any construction activity, a removal application must be submitted with the building permit application and will be reviewed along with project plans for consistency.

Complete the Protected Tree Permit Application and send it through to the CSS Portal. Choose the Residential Building Permit Application or Commercial Building Permit Application, whichever is applicable.

The CDD Managing Arborist and City staff will review what’s submitted to ensure your file contains all the materials necessary for your project to be reviewed.  

If you have questions, contact the Building Department at (650) 522-7172 or building.info@cityofsanmateo.org

For any other removal or pruning of street trees, contact the Parks and Recreation Tree Division. 

 - For trees and development projects, if you have submitted a planning application or building permit, or are planning to submit one, contact the Community Development Department Arborist at arborist@cityofsanmateo.org

 - For street trees (not related to development), visit the Parks and Recreation Tree Division website.

 - The City does not get involved in civil disputes related to trees. For mediation assistance, you may consider reaching out to the Peninsula Confliction Resolution Center (PCRC) or other professional mediators. Find more information on the California Judicial Branch “civil cases” website.