Boundary Line Adjustment


A Boundary Line Adjustment (BLA) is required for approval of adjustments or alterations to boundary lines of existing lots of record. A BLA cannot create any additional lot, tract, parcel, site or division and any lot altered through a BLA must have sufficient area and dimensions to meet minimum requirements for width and area for a building site. A BLA must be consistent with the minimum lot size for the zone (except for Agricultural BLAs).


The process includes submittal of a Boundary Line Adjustment Application (PDF) with appropriate fees to Planning and Development Services (PDS). PDS staff will then route the application to members of the Technical Review Committee including Critical Areas, Plans Examiner, Public Works, and Fire Marshal’s Office.

Staff will then either issue preliminary approval, a request for more information or a denial of the application. The applicant must then have a surveyor prepare a map and deeds must be written to reflect the proposed BLA. Staff will then stamp the map and deeds and the applicant must have them recorded with the Whatcom County Auditor within 1 year of preliminary approval.

Agricultural Boundary Line Adjustment

An Agricultural Boundary Line Adjustment (AG BLA) is processed similar to a standard BLA, however the minimum lot size may be reduced to 1 to 3 acres pursuant to the requirements of Whatcom County Code 20.40.250. In an AG BLA the small lot must contain an existing single family residence and the remainder lot (at least 10 acres) must contain a deed restriction stating there shall be no single family residential density associated with the remainder.