Residential Additions Guidelines

Plan Requirements

After consulting with the Planning Division regarding parking and lot coverage, design and preparation of plans may begin.

The City requires three complete sets of plans be submitted for review. A set of plans consists of:

• Any required elevations and details
• Energy calculations
• Floor plans
• A plot plan

Three complete sets of plans are to be submitted. This enables all City divisions and departments to review the plans simultaneously, thereby saving you time. The minimum paper size for plans is to be 11 inches by 17 inches or larger. Images of sample floor and plot plans are available in the last tab on this page.

Who Draws the Plans?

The City does not require plans be prepared by an architect or engineer in most cases. This includes:

• Construction of rooms downstairs, inside the original foundation
• One and two story additions prepared in accordance with the conventional light-frame construction provisions of the California Building Code (CBC)

Second story additions and one or two story additions not meeting the CBC conventional construction provisions require drawings prepared by a California registered architect or engineer. Supporting calculations will need to be provided demonstrating structural compliance with the building code.

The designer's wet stamp and signature will need to appear on the first page of the calculations and on each plan sheet.

Energy Requirements

Applications for rooms down and additions must be accompanied by Title 24 energy calculations. Forms CF-1R and MF-1R signed by the owner and designer must appear on the plans.

Plot Plan

The plot plan shows the layout of the house on the lot. Plot plans are normally drawn on a 1/8 inch to 1 foot scale. The plot plan must show:

• The length and width of the lot
• The location of the building structure(s) on the lot with the new and existing portions clearly indicated
• The length and width of the existing and proposed driveway
• Utility connections
• If the project is an addition, the method of carrying roof runoff from the addition to the street is to be shown

Floor Plans

Floor plans are drawn on a ¼ inch to 1 foot scale. Floor plans must include:

• All floors, the garage and all rooms
• The usage and ceiling height of each room
• All plumbing fixtures, existing and new
• Windows, including existing and proposed, and indicate size and type
• Doors, including size and type
• All proposed electrical fixtures, switches, outlets and smoke detectors in the addition
• Furnace, water heater and the laundry facilities

Clearly indicate what is new and what is existing.

Details & Elevations

Plans for additions outside the existing foundation must include details and elevations.

Details should include:

• Footing/foundation design
• The method of attachment of the addition to the existing structure at the foundation, each floor level, and the roof
• A flashing detail
• A nailing schedule
• A plan for erosion control during construction
• Details for any other feature which may require additional explanation

Special Smoke Detector Requirements

The California Building Code (CBC) requires smoke detectors be installed when rooms are added or additions are made to single-family homes. Install smoke detectors:

• In each (existing and new) bedroom or sleeping area
• At points centrally located outside of each bedroom or sleeping area

Smoke detectors are to receive their power as follows:

• In existing construction, from a battery
• In new construction, from the building's electrical system with a battery backup

Carbon Monoxide Requirements

The California Building Code (CBC) requires carbon monoxide alarms to be installed. Install carbon monoxide detectors:

• Outside each separate dwelling unit sleeping area in the immediate vicinity of the bedroom(s)
• On every level of the dwelling unit where there is habitable space

Under Construction

Submitting an Application

• A completed application form is to be submitted along with building plans
• A plan check fee is collected at the time of application. The fee is dependent upon the size and extent of the proposed construction work
• Plans are normally reviewed within fifteen working days

Following completion of the plan check, the City will mail you notification either approving or denying your application:

• If approved, permits are ready to be obtained and permit fees will be calculated. You will need to come into our office to pay these fees and obtain the permits prior to beginning work
• If denied, you will receive a list of plan check comments. Plans will need to be revised and resubmitted to comply with the comments

To ensure that you have completed the correct application or for more information, contact the Building Division by email or by calling 650-991-8061.

Obtaining Permits & Beginning Construction Work

Permits may be obtained by the homeowner or a licensed contractor:

• A homeowner may obtain permits if he/she or the immediate family intends to do the work
• If the work is to be done by others without compensation, the owner will need to furnish proof of worker's compensation insurance
• If the work is to be done by others for compensation, the permit will need to be obtained by a State of California licensed contractor

After paying permit fees and obtaining permits, the work may begin.

Inspections

As work progresses, inspections must be obtained before any work is covered or concealed. Normally, inspections are scheduled for the following:

• Foundation (before concrete is placed)
• Underfloor plumbing
• Framing
• Rough electrical, plumbing and mechanical
• Insulation
• Sheetrock nailing
• Final inspection

Inspections are scheduled by telephoning our office at 650-991-8061, before 3:30 pm the working day before you need the inspection. You will be given the choice of a morning or afternoon inspection. Inspection hours are normally between the hours of 8:30 am and noon, and 1:30 and 5 pm, Monday through Friday.

You may call our office between 8 and 8:30 am the morning of the inspection to obtain a more specific time (except on Wednesdays when the office is typically closed for a weekly staff meeting).

Please Note
If the work inspected is found to be incomplete or incorrect, or if no one is present when the inspector arrives, a reinspection fee in the amount of $150 will be charged. This fee covers the City's cost of having to return to the site for another inspection.

Rooms are not to be occupied or otherwise used until a final inspection has been approved.

Permit Expiration

• A building permit issued after January 1, 2019 expires if work is suspended or abandoned for a period of 12 months. Permits issued before January 1, 2019 are subject 180 day progressive inspection timelines
• The building code requires the permittee make substantial progress on the construction project and schedule an inspection within this time period to maintain an active permit
• If a permit expires, it will need to be renewed before work may recommence and permit renewal fees will need to be paid

Contact the Building Division at 650-991-8061 for more information.

Enforcement

If your application was submitted as a result of the City undertaking enforcement action on your property, it is important that the application materials be approved, permits be issued, and the work be completed in a timely fashion.

Lapses in any of these processes will result in resumption of enforcement action and incurring of enforcement fees at our standard hourly rate for staff time incurred.

Additional Information

For zoning, parking and lot coverage information, contact the Planning Division at 650-991-8033.

For building code, application, or permitting requirements, contact the Building Division at 650-991-8061.

Sample Plans