Tree Protection Code

See also: Tree & Vegetation RemovalGreen Factor

What Is It?

Our Seattle Municipal Code (SMC) limits the number, size, and type of trees that may be removed from your property. A Tree & Vegetation Removal permit is required when removing exceptional trees or more than 3 trees 6-inches or greater in a one-year period. The City also has restrictions and permit requirements for when you can remove shrubs and other vegetation in environmentally critical areas (ECAs).

In general, the following rules apply when removing trees or otherwise modifying vegetation.

Undeveloped land. Undeveloped land is a parcel or lot that has no structures or no legally established land use. You cannot remove any tree 6 inches or greater in diameter (measured at DBH (diameter at breast height) or DSH (diameter at standard height), both of which are measured 4.5 feet above ground), unless the tree is designated as a high-risk hazard. See Tip 331B, Hazard Trees, for more information.  To determine if the tree or trees are a high-risk hazard, you must get a hazard tree assessment from either a certified arborist or a registered consulting arborist with the ISA tree risk assessment qualification and apply for a permit. See Tip 242, Tree Protection Regulations in Seattle, for more information.

Developed property. Developed property is a parcel or lot that has legally permitted structures or uses.

  • You cannot remove any exceptional trees unless they are determined to be a high-risk hazard (Tip 331B, Hazard Trees) . Exceptional trees are trees that are above a certain size for their species and have historical, ecological, or aesthetic value (Director's Rule 16-2008, Designation of Exceptional Trees).
  • You cannot cut down more than 3 non-exceptional trees 6 inches or greater in diameter each year unless the tree is designated a high-risk hazard by permit.

You can find information about applying to remove a hazardous tree on our Tree & Vegetation Removal webpage.

Developing property. If you are developing your property, you may remove trees if retaining them prevents you from achieving the allowed lot coverage or floor area of the site's land use zone. You must show that it's not possible to retain the trees by using various "departures" from the zone's land use code development standards (see SMC 25.11.060, 25.11.070, and 25.11.080). We will review your tree and vegetation plans as part of your permit application. Also, depending on your project and it's zoning, you may be required to plant new trees. Retaining existing trees helps you meet those requirements. You will receive more credit toward tree retention requirements if you retain mature, healthy trees. 

Environmentally critical areas. You cannot remove any trees or otherwise modify vegetation from the following environmentally critical areas without an approved stand-alone ECA Restoration Plan or an ECA Restoration Plan approved with an issued building permit:

  • Landslide-prone critical areas
  • Steep slope erosion hazard areas and their buffers
  • Fish and wildlife habitat conservation areas
  • Riparian corridors
  • Wetlands and their buffers

You can find information about applying for an ECA Restoration Plan on our Tree & Vegetation Removal webpage.

Shoreline District. In general, you cannot remove any trees or vegetation from the Shoreline District without an issued Shoreline Exemption or issued building permit. The regulations on Shoreline District vegetation are found in SMC 23.60A.190. The Shoreline District is generally the land within 200 feet of a shoreline and also larger bodies of water. The restriction on tree and vegetation removal in the Shoreline District is the same, regardless of whether the area is an environmentally critical area. Tree removal in the Shoreline District must also comply with the Tree Protection Code.

Protecting trees during development. See the Department of Natural Resources' Tree Protection on Construction and Development Sites for a good overview of tree care and protection measures. Some details and requirements are different from ours. In those few situations, you need to follow SDCI's tree protection rules.

Read the Code

For more information on existing regulations, read:

Recent Changes

On April 19, 2019, we amended a subsection of 25.11.040.A.3 of the Municipal Code to eliminate the exemption from tree protection for lots under 5,000 square feet. Now all exceptional trees are protected, no matter the lot size.

Director's Rule 17-2018, Calculating Tree Valuations and Civil Penalties for Tree Protection Code Violations became effective May 14, 2018.