Property Line Changes

See also: Land Use / Master Use Permit - Plat

What Is It?

Property Line ChangesA property line change involves moving the property boundary between your property and the property next to yours. Most often, our customers want to move the property line of a single-family house.

You may want to move your property line to:

  • Include a building, such as your garage, that does not fully lie on your property
  • Correct a boundary disagreement between you and another property owner
  • Create lots that are each big enough to build upon
  • Adjust existing lots so each are big enough to build on separately

You cannot create a new lot by moving your property line.

What Permits Do You Need?

You need a Land Use / Master Use Permit - Plat permit to make changes to your property line.

Research the Code

You need to show us that moving your property line will still maintain lots which conform to our land use rules in the Seattle Municipal Code (SMC) and our building codes.

If your property is in a single-family zone (SF5000, SF7200, or SF9600), you need to follow the rules below. For complete requirements, consult the land use code (SMC 23.44).

If your lot is in zone other than single-family, we may have different rules for you to follow; consult our land use code or ask our land use planners.

Minimum lot size. The minimum lot size depends on which single-family zone your house is in.

Minimum yards. Your single-family house can’t be too close to the property line.

Parking and access. Your single-family lot must meet our rules for parking and car access to your property. Usually, we require you to maintain the property’s parking spaces and access to them. At a minimum, we require one parking space per lot.

Regulations that govern environmentally critical areas. If your single-family lot is in an environmentally critical area, you must have a survey that delineates the area on a drawing when you apply for a lot boundary adjustment. We may have other requirements.

Utility service. Your single-family lot must meet our minimum levels of service for water, sewer, power, and fire access.

Fire separation between buildings. If you’re moving your property line, the line’s new location should be at least 5 feet from your single-family home, garage, and related buildings. In most cases, your buildings’ walls and eaves must be fire rated if they are less than 5 feet from your property line’s new location.

  • Seattle Residential Code R302

Should You Hire a Professional?

A licensed surveyor usually creates the documents for your lot boundary adjustment application. In some cases, you may create them if you can develop scaled drawings with lot lines, bearings, right-of-way information, building and lot line dimensions, and location of all utility services and trees.