Lot Segregations and Combinations

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Lot Segregation

Parcels that contain numerous lots can be considered under the “Lot Segregation Process” if a parcel has underlying lot line(s) and the proposed Segregation results in multiple parcels that meet the minimum requirements for buildable parcels.

To meet the minimum requirements the resulting parcels must not only meet lot size and width requirements; considerations are also given to any potential critical areas and buffers, as well as the ability of the parcels to be developed in accordance with applicable setback requirements and standards. For this reason, when a Lot Segregation is proposed, the applicant could potentially be asked to supply additional information, such as a survey or a critical areas report, to demonstrate that the resulting parcel(s) are capable of being developed.

What is an underlying lot line?

When the City was originally platted in the 1800s, lot lines were created to establish ownership boundaries for property sales. In many older areas of Tacoma (ex. Hilltop and Old Town) the lots are 25 feet in width. These original lot lines establish what may often be referred to as a legal lot of record.

In 1953, the City’s first Zoning Code was established, with minimum lot widths and lot sizes. In residential areas the minimum lot size was generally established as 5,000 square feet and the minimum average lot width was generally established as 50 feet. Therefore, in most instances at least two original lots of record were required to form new buildable parcels that met Zoning Code.

Per the Zoning Code:

  • A lot is defined as “A designated parcel, tract, or area of land established by plat, subdivision, or as otherwise created by legal action.”
  • A parcel is defined as “A single platted or unplatted lot, or contiguous lots, or tract of land having the same Pierce County Assessor’s tax identification number. A parcel is usually considered a unit for the purposes of development.

Many properties (parcels), within the City contain numerous lots of record. The lot lines within a parcel are referred to as underlying lot lines.

In the image to the above, the map shows parcel lines and underlying lot lines that were created with the original City plat. In this case, the area was originally platted in 1927.


The Lot Combination Process is the process in which an applicant combines two parcels, generally for the purpose of making a site more desirable for development, or for removing a parcel line that goes through an existing or proposed building. Code requirements do not currently allow for a permit to be issued for a building over an existing parcel lines, except in limited circumstances where appropriate Fire protection considerations have been implemented and where the Zoning Code allows.

Property lines that cross buildings, like the one shown here, are oftentimes required to be removed via the Lot Combination Process unless it can be demonstrated that the building meets requirements of all applicable Codes.

For Tax Purposes Only

Segregation and Combinations can affect how property is taxed. Pierce County has a form available titled Request for Tax Purposes Only Segregation/Combination. The Planning and Development Services Department (PDS) is not involved with Segregation and Combinations that are done for tax purposes only. PDS only reviews Segregation and Combination requests that affect buildable parcel area. For more information on requests that are for tax purposes only, contact Pierce County Planning and Land Services (PALS): www.co.pierce.wa.us.


Although the Lot Combination/Segregation is processed through Pierce County, a City application for a Land Use Permit still needs to be submitted. Begin by completing the County’s form and save it electronically as a PDF document. Then follow these steps:

  1. Log in at https://aca-prod.accela.com/tacoma/Default.aspx
  2. Select Permits, then accept the disclaimer.
  3. Select the Land Use Drop Down box and Land Use option. Then select Continue Application.

Click “Continue Application”

4. Follow the prompts to continue filling in the required information. When you get to Step 2 : Details and Attachments > Detailed Information there will be an area under Permit Information to choose a Permit Type. Select the Add an Application Type button.

Add an application type.

5. Select the Plats/Short Plats/Boundary Line Adjustments option. Then click Next.

Plats/ Short Plats/ Boundary Line Adjustments

6. . Select Segregation/Combination. Then click Finish.

Sub Category

7. Add a Project Description. Then click Submit.

Project Description

8. Upload the completed Pierce County form as an attachment when prompted to Add Attachments.

Add attachments

9. After the submittal process has been completed via the City’s website, an LU number will be assigned to the proposal. A Planner will be assigned to process the Segregation/Combination request. Generally, these types of requests can be processed by the City within a week of submittal.

10. After the Planner assigned to process the request has signed off on the County Form, they send a scanned copy to Pierce County via email. The applicant will be cc’d on that email to the County. If building permits are dependent upon the Segregation/Combination request approval, those building permits can be issued at that time.

11. It may take a number of weeks for the request to be officially processed by Pierce County and, if a new Parcel Number is required for a segregation, it may take a few weeks for that parcel number to be assigned. If you have questions about the status of the request after the City has signed off and submitted the form to Pierce County, it is usually best to contact Pierce County directly: www.co.pierce.wa.us

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