Business & Professions Codes provide the following exceptions for building plans that have been designed in accordance with the Building Code requirements of Chapter 23 for conventional light wood-frame construction and tables of limitation for wood frame construction as adopted by the local jurisdiction.

Unless the Building Official deems that an undue risk to the public health, safety or welfare is involved, or if any portion of any structure exempted by these sections deviates from the requirements for conventional light wood-frame construction or tables of limitation for wood frame construction found in Chapter 23 of the Building Code, the Building Official may require the preparation of plans, drawings, specifications or calculations for that portion by, or under the direct supervision of, a licensed engineer or architect. The documents for that portion shall bear the stamp and signature of the licensee who is responsible for their preparation.

An unlicensed person may prepare plans, drawings or specifications for the following:

• Single-family dwellings of wood frame construction not more than 2 stories and basement in height. With spans between bearing walls not exceeding 25 feet and the height of the structure does not exceed 25 feet.
• Nonstructural or non-seismic store fronts, interior alterations or additions, fixtures, cabinetwork, furniture, or other appliances or equipment.
• Nonstructural or non-seismic alterations or additions
• Fabric awnings and canopies
• Signs that weigh less than 400 pounds are less than 24 square feet in area and projects less than 4 feet.
• Multiple dwellings containing not more than four dwelling units of wood frame construction, not more than two stories and a basement in height. A single lot may have a maximum of four dwelling units per lot. This shall not be construed as allowing an unlicensed person to design multiple clusters of up to 4 dwelling units.
• Garages or other structures appurtenant to single family dwellings, of wood frame construction not more than two stories and a basement in height
• Agricultural and ranch buildings of wood frame construction
• May not prepare plans for those alterations that will change or affect any components of the structural system or safety of the building or its occupants.

Plans prepared for the following work shall be deemed as affecting the safety of a building or its occupants and shall be prepared by, stamped, and signed by a licensed engineer or architect:

• Projects with interior or exterior structural alterations
• Interior alteration with an occupancy change
• Interior alteration with walls and partitions over 5'9" in height or ceiling work which cover a floor area greater than 3,000 square feet in B, F-1, F-2, S-1, S-2 and M occupancies
• Storage racks over 8' in height
• Remodeling projects with changes to fire walls, barriers or partitions
• Alteration with change to exiting requirements
• All Group H (Hazardous) Occupancies
• Assembly occupancies A-1, A-2, A-3 and A-4
• Tanks and vessels
• Roof mounted mechanical equipment weighing more than 400 pounds, and/or extends more than 4 feet above the line of the roof
• All Group E Occupancies (School and day care classified as educational group E occupancies)
• All Group I (Institutional) Occupancies
• Hotel, motel and apartment occupancies R-1 and R-2
• Projects with mixed occupancies
• Remodeling projects in a high-rise building (having floors over 75' in height)
• Lateral force resisting systems utilizing poles embedded in the ground
• Cripple walls exceeding 4' in height or adjacent to garage door openings
• Nonstructural component or equipment attached to building requiring seismic design per

  Chapter 13 of ASCE 7 Minimum Design Loads for Buildings and Other Structures,

• All new construction of buildings and portion of buildings, including substantial improvements to buildings, located within flood hazard areas that are subject to Section 1612 of the California Building Code or ASCE 24 Flood Resistant Design and Construction,

• Any project not deemed exempt by the Building Official.

• Any project deemed by the Building Official to require professional design by a California licensed engineer or architect

What Construction Documents Are Required to Be Signed and Wet Stamped?