Safety is the primary reason for building code regulations. The building permit process is a way for the City to regulate the building codes. A building permit is needed for all renovation and new construction. In many cases, a building permit is also needed for repair or replacement of existing fixtures, such as windows replacement. A mechanical, electrical or plumbing permit maybe needed for changes or addition to the existing mechanical, electrical or plumbing system; for example, moving or adding an electrical outlet or a plumbing fixture requires a permit. Most building permits need drawings submitted to the City to show the improvements and the type of construction being proposed. Once the permit is issued, you’re required to build the project and if any changes are made to the work, it must be made with the City’s approval. Some permits can be issued over-the-counter while other permits require additional time for reviews. In San Francisco, a building addition permit can take up to 18 months because most addition project requires public notifications. Remember that the building codes were created for safety reasons. If you perform work without permit, then, it is a violation of codes and regulations and you will be subject to fines and penalties. You will also require to obtain permits for the work created and if the work does not comply with codes, you will have to demolish the work.
The following are examples of work that does not require a building permit in San Francisco.
1. One-story detached accessory buildings used as tool and storage sheds, workshops, playhouses and similar uses as long as the projected roof area does not exceed 100 sq.ft.
2. Plastic, metal or wood fences not over 6 feet high located at the rear and side of the property and any fence not over 3 feet in height along the front of the lot.
3. Movable cases, counters and partitions not over 5 feet 9 inches high.
4. Retaining walls that are not over 4 feet in height measured from the bottom of the footing to the top of the wall. If this wall is supporting a surcharge, then it will require a permit.
5. Water tanks supported directly upon grade if the capacity does not exceed 5,000 gallons and the ratio of height to diameter or width does not exceed two to one.
6. Platforms, walks and driveways when not part of an exit, and not more than 30 inches above grade and not over any basement or story below.
7. Painting, wallpapering and similar finish work.
8. Minor repairs to existing interior plaster or wallboard, except when part of a fire-resistive assembly such as any wall along the property line.
9. Prefabricated swimming pools accessory to single family or duplex occupancy in which the pool walls are entirely above the adjacent grade and if the capacity does not exceed 5,000 gallons.
10. Re-roofing without the installation, repair or removal of roof sheathing, if the total re-roofs surface area in any 12-month period does not exceed 25 percent of the entire surface area of the roof.
11. Surface mounting of readily removable materials on interior walls.
12. No more than 200 square feet of paved or covered ground. Any paved or covered ground area exceeding 200 square feet requires a plumbing permit.
13. Installations or replacement of floor coverings not requiring the removal of existing flooring except bathrooms and toilet rooms.
14. Replacement of doors, except garage doors, in all occupancies, provided they are not required to be fire-resistive assemblies by San Francisco Building Code.
The above exceptions summarizes most but not all the rules, for a complete list of rules and regulations please see San Francisco Building Code 106A.2 and 2010 California Building Code section 105.2.
Other than the list above, all other work will require a permit. The following are answers to some of the most common building code questions.
1. Generally, openings such as windows are not allowed within 0 to less than 3 feet from the property line, unless the windows are facing a street or back yard. Limited windows areas are allow from 3 feet to less than 5 feet. For residential projects, openings are not limited when they are located at 5 feet or greater from the property line.
2. Generally, the minimum ceiling height is 7′-6″. Bathrooms, toilet rooms, kitchens, storage rooms and laundry rooms shall be permitted to have a ceiling height of not less than 7 feet.
3. The size of bedroom window for emergency escape in a wood frame non sprinkler residential buildings should have a minimum net clear open area of 5.7 square feet. The minimum net clear opening height shall be 24 inches. The minimum net clear opening width shall be 20 inches.
4. Natural Ventilation: The minimum net openable window to the outside is 4 percent of the area of the room.
5. Natural Light: The minimum net glass area is 8 percent of the floor area of the room.
6. Heating: Spaces for human occupancy shall be heated and maintain a minimum indoor temperature of 68°F at a point 3 feet above the floor.
7. If you plan to expand your building, consider the following questions.
A. Will the expansion trigger additional parking?
B. Has the building reached its maximum allowable size or floor area ratio (FAR)?
1. In City of Millbrae, R-1 single family zone, the allowable area is 55% of the lot area.
2. In San Francisco, the horizontal and vertical setbacks takes more precedent over percent of lot area coverage.
3. In City of Sunnyvale, a single family house in R-0, R-1 and R-2 zone is limited to 3600 square feet or 45% of the lot area whichever is less.
C. Has the building reached its maximum allowable height limit? Most single family zones in San Francisco have a height limit of 40 feet. Most of the other neighboring cities are approximately 30 feet.
D. Does the project meet the Lot Coverage requirement or the maximum allowed foot print for the building.
1. In City of Millbrae, R-1 single family zoning district, the maximum allow lot coverage is 50% of the lot area.
2. In San Francisco zero-lot line properties, the maximum buildable area is control by setbacks and the average of the front and back walls locations of the immediate adjacent properties.
3. In City of Sunnyvale, it is 45% of lot area for 1 story or 40% for 2 stories.