Projects that Require a Building Permit
can safely assume that all construction activity, from initial grading
of a site to interior improvements, alterations and most repairs,
requires a building permit. However, there are exemptions for
small detached structures and ordinary repairs. (The Thurston
County Permit Assistance Center issues permits for development in
unincorporated Thurston County only. If your project is within city
limits, please contact the city instead.)
If you are unsure whether you need a
building permit for a project in Thurston County, please call the Permit
Assistance Center at (360) 786-5490 or TDD line (360) 754-2933.
This page focuses on residential building permits. If you plan to
develop land that contains critical areas or shorelines, or to subdivide
property, please see our web pages on
Land Use Ordinances and
Land Use Applications.
If you are proposing a nonresidential (commercial) project,
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Projects that Require a Building Permit
Generally speaking, a permit is required if you are starting a new
construction project, remodeling and planning to change the footprint of
an original structure, changing the roof pitch, or making any structural
changes. Before seeking a permit, though, you should make sure that your
project is actually allowed in
the area in which you are building.
For example, a building permit is required if you
Building or installing:
- A new structure (unless it is a one-story detached accessory structure used as
tool or storage shed, playhouse or similar use, and the
floor area does not exceed 200 square feet.)
- Porches, decks and patios that are more than 30 inches above
grade (see below)
- Cover to a patio or deck
- Garages and carports
- First time installation of fixtures and appliances permanently
connected to the electrical, mechanical, gas and/or plumbing
system(s). Approval typically happens as part of the inspection
- Fences and privacy walls higher than 8 feet.
- Sheds that are attached to a house.
- Sheds or playhouses that are detached if they are greater than
200 square feet.
- Swimming pools 24 inches deep or more (see below)
- Attic pull-down stairs
- Retaining walls supporting more than 4 feet of earth.
Adding to or changing:
- Attics, finishing
- Basements, build or enlarge
- Dormers, bay windows or other wall openings
- Water heater or any other parts of the plumbing
- Furnaces and any other parts of the heating and gas system
- Circuits or any other parts of the electrical system (click
here for information about electrical permitting).
- Walls to a porch
- Garage to livable area
Repairing or replacing:
- Roofing repairs that are 200 square feet or larger
- Replacing siding/foundation
- Existing stone, brick or concrete
Projects that Do Not Require a Building Permit
Permits are not required for the following when related to single-family homes,
provided do not
encroach over a subsurface drain system, public utility easement, or into
buffers or required setbacks
from property lines:
- One-story detached accessory structures not exceeding 200 square
feet (18.58 m2) that
meet the requirements for property line protection and occupancy
separation of IBC Chapters 5 and 6 and are used for
tool and not-business related storage, playhouses and similar uses.
- Fences not over 8 feet (2438.4) high measured from the highest
point to grade.
- Oil derricks.
- Retaining walls that are not over 4 feet in height measured
from the bottom of the footing to the top of the wall, unless they
support surcharge (ie, holding back a load, such as a slope) or
impounding Class I, II or IIIA liquids (ie, flammable liquids).
- Water tanks supported directly on grade if the capacity does
not exceed 5,000 gallons and the ratio of height to diameter or
width does not exceed 2 to 1.
- Sidewalks and driveways not more than 30 inches above adjacent
grade, and not over any basement or story below and are not part of
an accessible route (ie, an access route required under the
Americans with Disabilities Act).
- Painting, papering, tiling, carpeting, cabinets, counter tops
and similar finish work
- Temporary motion picture, television and theater stage sets and
- Prefabricated swimming pools accessory to a Group R-3 occupancy that are less than 24 inches deep,
do not exceed 5,000 gallons and are installed entirely above the
ground. Group R-3 refers to one and two-family dwelling units, or
adult and child care facilities that provide accommodation for five
or fewer persons of any age for less than 24 hours. (Click
here for occupancy definitions)
- Temporary growing structures for commercial production constructed with the roof and side
of polyethylene, polyvinyl or similar flexible synthetic material,
used to provide plants with either frost protection or increased
heat retention. For commercial growing, this is pursuant to
- Swings and other playground equipment accessory to detached one-
and two-story family dwellings.
- Window awnings supported by an exterior wall which do not
project more than 54 inches from the exterior wall and do not
require additional support of Groups R-3 and U occupancies. Group
R-3 refers to one and two-family dwelling units, or adult and child
care facilities that provide accommodation for five or fewer persons
of any age for less than 24 hours. (Click
here for Group U occupanices, which typically include barns,
carports, private garages, sheds etc.)
- Non-fixed, movable fixtures, cases, racks, counters and partitions not over 5 feet 9 inches
(1753 mm) in height constructed under the International Building
- Replacement of roof coverings.
- Patios or decks not more than 30 inches above the adjacent grade that are
accessory to structures constructed under the International
Typical home improvement projects that do not
require a permit
- Ceramic, tile, hardwood floors, carpet.
- Crown molding, baseboards, trim.
- Replacement of a glass or glazing within
an existing window pane or a door within the existing frame. If you are widening or changing the door frame or
window frame, you will need a permit.
- Gutters and down spouts.
- Kitchen cabinets (new and existing)
- On-grade patios, decks and porches
- Recreational equipment (swings, jungle gyms, skateboard ramps,
- Small-scale roof repairs
- Detached sheds or playhouses that are 200 square feet or less in
size. Note: You must still meet setback requirements per
the zoning ordinance (see Chapters 20, 21, 22 and 23).
Projects that Do Not
Require a Gas (Minor) Permit:
- Portable heating device
- Portable ventilation equipment
- Portable cooling unit
- Steam, hot or chilled water piping within any heating or cooling
- Replacement of parts
- Portable evaporative cooler
- Self-contained refrigeration system containing 10 pounds or less
of refrigerant and actuated by motors of 1 horsepower or less.
Projects that Do Not
Require a Plumbing (Minor) Permit:
- The stopping of leaks in drains, water, soil, waste or vent
pipe, provided, however, that if any concealed trap, drain pipe,
water, soil, waste or vent pipe becomes defective and it becomes
necessary to remove and replace the same with new material, such
work shall be considered as new work and a permit shall be obtained
and inspection made as provided in this code.
- The clearing of stoppages or the repairing of leaks in pipes,
valves or fixtures and the removal and reinstallation of water
closets, provided such repairs do not involve or require the
replacement or rearrangement of valves, pipes or fixtures.
Be sure to visit our
FAQs page for answers to common questions we
receive at the Permit Assistance Center.
Thurston County Permit Assistance Center, 2000 Lakeridge Drive SW,
Olympia, WA 98502-6045.
Phone: (360) 786-5490. TDD line: (360) 754-2933. E-mail: