The California Energy Commission (CEC) defines a residential room addition, in part, as any change to an existing building that increases the conditioned floor area and volume.

A conditioned space is enclosed space that is provided with heating, cooling, humidification and dehumidification for the provisions of human comfort by transporting air through ducts and plenums, or by heated or cooled surfaces whose output is greater than 10 BTU per hour per square foot of floor area.

Additions may be either single story or two story.

PLANNING AND DEVELOPMENT REQUIREMENTS

Room additions may be made to any part of the home, providing the addition is consistent with the following regulations:

• The addition must meet the setback requirements for the home, except for the rear-yard setback, which must be a minimum of 15 feet.
• A rear-yard addition may cover up to 20 percent of the rear-yard setback area.  In combination with an accessory structure, the addition may cover up to 30 percent of the setback areas.
• Contact your local Department of Planning and Development at  to inquire about setback requirements or for any other questions related to these regulations.
• To locate your Department of Planning and Development call the City Hall of the city that you live in for assistance.

REQUIRED DRAWINGS

It is not necessary to be a proficient draftsman; however, a plan with the following basic information must be submitted on 18" x 24" minimum size paper, drawn to a scale of 1/4" = 1' showing the following:

Plot Plan - showing the position of the proposed project in relation to existing buildings, property lines and public utility easements. This plan is to be drawn to a scale of 1:20, which means 1 inch is equal to 20 ft.

Foundation Plan - indicating the type of foundation and the size of footing used.  The foundation should match the size of the existing house foundation. (A handout is available through the Building Division Office)

Framing Section - showing sizes of framing members and methods of assembly and the R-value of insulation being used.

Floor Plan – with details identifying: the location of walls, supports, size and location of doors, windows, electrical outlets, heaters, plumbing fixtures, smoke detectors and the square footage of the project.

Elevations - showing two or more sides of the proposed structure.

NON-STRUCTURAL CONSIDERATIONS

Garages - If the addition forms a common wall between the garage and the addition the wall must be constructed with one-hour fire resistive materials on the garage side extending from the garage slab to the roof. Door openings are protected with a solid core, self-closing, tight fitting, one and three-eights inch minimum thickness door. Electrical wiring, plastic plumbing piping and ducts penetrating the firewall within the garage must be encased in metal that has the equivalent thickness of 26 GA galvanized steel.  Doors from the garage are prohibited from opening into a bedroom space.

Room Sizes - Habitable rooms other than a kitchen will have an area of not less than 70 square feet with a minimum of seven feet in any horizontal direction.

Ceiling Height - Habitable rooms shall have a ceiling height of not less than seven feet six inches. Other rooms may have a ceiling height of not less than 7 feet.

Windows - All habitable rooms need skylights or windows for natural light. The minimum window area is not less than 1/10 of the floor area with a minimum of 10 square feet. If the window serves as an emergency egress for a bedroom, it must have an opening to the exterior of the building of at least 5.7 square feet with a minimum clear opening width of 20 inches, a clear opening height of not less than 24 inches, and a finished sill height not more than 44 inches above the floor.

Ventilation - Ventilation of habitable rooms may be by either mechanical or natural means. Operable exterior windows, doors, or skylights with an area of not less than 1/20 of the floor area of the habitable room with a minimum of 5 square feet may be used to provide natural ventilation. Mechanical ventilation shall be capable of providing two changes of air per hour in habitable rooms. For bathrooms or laundry rooms mechanical ventilation must provide five changes of air per hour.

Smoke Detectors – Installation of smoke detectors are required when the value of the addition exceeds $1,000, or when one or more sleeping rooms are added. The smoke detectors may be solely battery-operated in buildings that undergo alterations, repairs or additions. They are installed in each sleeping room and at a central location in a corridor giving access to sleeping areas. If the addition is a 2 story, a smoke detector is required at each story, and if the sleeping rooms are on the upper level, the detector is placed at the center of the ceiling directly above the stairway.

STATE BUILDING ENERGY EFFICIENCY STANDARDS

In accordance with the California Code of Regulations Title 20 and Title 24, all new construction must comply with the building energy efficiency standards in effect on the date a building permit application is filed. The standards apply to any addition that increases the conditioned area of a building.

Compliance options for additions:
Three methods may be used to demonstrate the compliance of the addition:

Method 1 - Prescriptive compliance measures show that the addition alone meets the energy budget by meeting specific requirements.

Method 2 - Point system is used when the addition does not meet the requirements of Method 1. The point system can be used to show compliance of the existing house and room addition as a combined unit or the room addition alone.

Method 3 - Computer method relies on computer programs to analyze the energy use for the addition alone or the addition and existing house as a combined unit.

In most cases room additions can easily demonstrate compliance by utilizing Method 1, the mandatory measures option.

Note: Method 2, the point system option, and Method 3, the computer method option, may require the services of Energy Consultants to develop the energy package for the addition.

Meeting the Method 1 Compliance Option

To comply with Method 1 for room additions, all of the following must be included and shown on the plans.

Insulation
 

Glazing

• Windows shall be dual pane with a U value of .65.  Additions less than 500 sq. ft. may have a U value not to exceed .75.
• The maximum total glazing area shall be 16% of additional floor area plus the square footage of any existing glass covered by the addition. Additions less than 100 sq. ft. are limited to 50 sq. ft. of glass.
• All doors and windows must be CEC certified and labeled accordingly.

Heating ventilation and air conditioning

• Exhaust fans and fan systems will be dampered.
• Ducts shall be installed per U.M.C. Chapter 10 and be a minimum R-4.2.
• Setback thermostats are required on new HVAC equipment.
• New space heater rated 78% heat efficiency (AFUE).
• Cooling equipment efficiency rating of 10.0 (SEER).

Water Heating

• If additional water heaters are added, water heating energy budget calculations are required.
• Exposed water heater pipe is insulated for the first five (5) feet.

Lighting

• General lighting in kitchens and bathrooms shall be fluorescent.

BUILDING PERMIT FEES

Fees are charged for each type of permit issued such as building, plumbing, electrical and mechanical. The permit fee is based on the valuation of the project, and calculated from fee tables established in the code. The fees provide for the checking of plans and adequate field inspection of the materials and methods of construction.  For room additions over 500 square feet a School Development fee is applicable. 

Upon issuance of the permit the Person pulling the permit has 180 days to commence work on the project.  The only person who can legally sign for the permit is the owner, an authorized agent, or a licensed contractor.

INSPECTIONS

All permits issued require an inspection during and/or at completion of the work. Scheduling inspections is the responsibility of the permittee. The following inspections are required for room additions:

Foundation - To be made after trenches are excavated, forms erected and steel is in place.
Under floor - To be made after the installation of under floor framing, heating ducts and plumbing.
Under floor Insulation - To be made after the insulation in the floor is installed, but prior to installation of the sub floor.
Roof Nail - To be made after installation and nailing of the roof sheathing.
Frame - To be made after the roof, all framing, fire blocking, siding, lath and bracing are in place and all pipes, chimneys, vents, rough electrical and plumbing are installed.
Insulation - To be made after the insulation in the ceilings and walls is installed.
Sheetrock nail - To be made after the sheetrock is installed and nailed and prior to tape or texture.
Final - To be made after the addition is completed and ready for occupancy.

Not all of the inspections listed above will apply to every job. If it is uncertain as to which inspections pertain, please check with the Building Division Office.