This is a list of minimum requirements for single-family residential projects. In unique situations additional materials may be necessary.
PLEASE NOTE: The planning division must approve the construction plans prior to submitting to the building division for a building permit. The planning division will review the plans to verify that all conditions of the design approval have been
The 2013 California Code of Regulations, Title 24, Including but not limited to, building, energy, electrical, green, mechanical, plumbing and residential codes, were adopted January 1, 2014. All residential detached one and two-family dwellings, townhouses not more than three stories above grade plane height with a separate means of egress are covered under the 2013 California Residential Code.
THE FOLLOWING INFORMATION SHALL BE INTEGRATED INTO FOUR (4) SETS OF PLANS AS APPLICABLE:
(Deferred submittals are only allowed under special circumstance
as approved by the building official. Truss calculations are not
considered special circumstance and are required in order to perform
the structural review)
An application for a permit for any proposed work shall be deemed to have been abandoned 180 days after the date of filing, unless such application has been pursued in good faith or a permit has been issued.
Phased construction is not allowed.
Separate structures (i.e. detached garage, cabana, pool house, swimming pools, car chargers and photovoltaic ) require separate permits. for the purpose of these submittal requirements “tear down” means existing portions of roof framing and/or exterior walls removed for the purpose of rebuilding and remodeling. Exception: New roof framing that tie in additions over existing roofed areas need not be included.
Los Altos is located within seismic design category e.
basic wind speed is 110 mph. this can be verified with ASCE-10. Most areas of Los Altos can be classified as wind exposure category B. However, some areas may meet the criteria for exposure C. The design professional is responsible for justifying the exposure selected for the specific area of construction.
Show all easements including those for public utilities, storm drains,
and the Santa Clara Valley Water District.
Show driveways and adjacent streets.
Show the type and location of all major landscaping (trees, screening, and shrubs) to be retained or removed and all proposed landscaping required as a condition of design review.
Show building pad elevations and finished floor elevations (except when no changes are proposed to existing elevations).
DO NOT show future pools, cabana, trellis or outdoor kitchens or work not included on permit application.
4. FLOOR PLAN
Show dimensions for all existing and proposed rooms and indicate use.
Show dimensions for all doors, windows and fixtures for kitchen and bathrooms.
Locate all electrical features. Include location of new and/or existing main service panel and all sub-panels.
Show skylights and their listed Evaluation Service Report
Provide window and door schedule.
Basement theaters/media rooms shall have either a direct emergency egress door or window to outside or a interconnected smoke detection and visual strobe installed when the entire building is provided with a NFPA 13D sprinkler system. Such rooms shall include adequate ventilation from EITHER:
A. Outside the building per 2013 CBC Section 1203.4.1.
B. Inside the building per 2013 CBC Section 1188.8.131.52 with the
door to the theater closed
Only decorative gas appliances, pellet-fueled wood heaters or EPA Phase II certified wood-burning appliances may be installed as permitted per Chapter 12.64 of the Municipal Code (Solid fuel burning fireplaces shall be EPA certified).
5. EXTERIOR ELEVATION DRAWINGS
Show the appearance of all exterior walls, roofs, doors, and windows, and indicate the finish materials to be used.
Clearly distinguish between existing and proposed construction.
Show the daylight plane drawn and dimensioned from the property lines
Show elevations of grade, finish floor, top plates and overall building height.
Indicate roof pitch.
6. CROSS SECTION DRAWINGS
Show the foundation/floor system, the wall plate heights and the roof pitch.
Show a minimum of at least two complete longitudinal and transverse cross-sections of new construction.
(Geotechnical reports required on new residences, second-story additions and basements)
Basement/below grade structures to show required excavation with cuts that would be less than or equal to 2:1 horizontal to vertical ratio. A cross section of cuts through the site beginning at the property lines to determine if a shoring plan is required per chapter 33.
The minimum acceptable scale is ¼” = 1’.
Show the under floor area to be excavated.
Show the foundation layout (foundation location, piers, grade beams, etc.). Show reinforcing steel, hold down devices and shear wall lengths.
Show the floor construction including floor framing size, spacing, floor sheathing and connection details.
Include calculations for any manufactured floor truss system. Truss calculations may not be deferred.
Indicate under floor ventilation method.
All new buildings and structures located in Seismic Design Category C, D, E or F require a foundation and soils investigation report per Sections 1803.5.11 and 1803.5.12 of the 2013 California Building Code (CBC). The foundation and soils investigations report shall be prepared, stamped, and signed by a licensed soils or geotechnical engineer.
Geotechnical engineer of record shall provide a stamped letter verifying conformance with report recommendations and project construction plans.
Foundation and soils investigations may not be required for items i, ii, iii, & iv, below; if the following minimum design requirements are incorporated into the drawings
i) One story addition to an existing single family dwelling.
ii) Accessory structures to an existing single family dwelling
such as attached or detached garages, patio covers, carports,
and similar structures.
iii) Non-residential miscellaneous structures not exceeding 15 feet
Allowable foundation pressure not to exceed 1500 psf.
Footing to have minimum reinforcement of : 2-#4 at top and 2-#4 at bottom.
The minimum depth of footings below undisturbed ground surface to be 12 inches.
Table 1808.8.1 CBC 2013 Minimum specified compressive strength 2,500psi. Prescriptive width and thickness of footings shall comply with Table 1809.7 of 2013 CBC.
8. ROOF PLAN
The minimum acceptable scale is ¼” = 1’.
Show ridges, hips, valleys, skylights, and the size and spacing of structural members.
Show location and framing details for any proposed skylights.
Show the roof pitch.
Indicate type of attic ventilation and number of openings required.
Include wet signed calculations for any manufactured truss system with submittal application. In addition to truss engineer, the engineer of record shall also review and stamp a letter of confirmation for the approval of applicable truss calculations.
A statement on the construction plans shall note that finished roofing material shall be installed and completed prior to frame inspection.
9. ELECTRICAL PLAN
Provide size and location of all electrical panel installations. All
new, relocated, additions or “Tear Downs*” over 50% of existing
building , excluding basements, shall have all utilities installed service lateral. (Underground). *See definition under general information
Provide electrical load calculations to justify size of electrical
service disconnect.(200 amp. service ok for 3000 sq. ft or less.)
Show location, type of fixtures and switching to comply with required
building energy efficiency standards, Title 24, Part 6.
Provide arc-fault, ground-fault, dedicated circuits, small appliance
Loads, motor load protection, smoke and carbon monoxide detectors per articles in the 2010 California Electrical Code (CEC) part 3/California Residential Code (CRC) Title 24, Part 2.5.
NOTE: PHOTOVOLTAIC AND ELECTRIC VEHICLE CHARGERS REQUIRE
10. PLUMBING PLAN
Provide an atmospheric and listed accessible back flow water valve installed for all new, repaired, replaced or altered building sewers (see handout).
Building sewers shall have an atmospheric relief valve installed
upstream of the backwater valve outside the building in close proximity to the foundation (see handout @building division). Provide street clean out 2’ to 5’ behind property line.
Show plumbing fixture drainage, waste and vent single line schematic
with pipe size for all underslab plumbing (basements). Isometric diagram may be required for complex plumbing plans.
Show fixture count and calculation for water supply line from
utility water meter to residence. Check with water purveyor and fire sprinkler contractor for additional check valve and sizing requirements.
Provide isometric diagram for all gas piping. Show distance and location from meter to most remote fixture; include sizes of all
branch lines with distances along with BTU ratings of all gas appliances (see figure 1216.1.1 and table 1216.2(1) California Plumbing Code 2013, Title 24, part 5).
Provide state architect certified earthquake-acuated gas shut-
off valves at all new, relocated, and replaced gas utility meters.
Show location of all mechanical equipment. Provide evaluation
report numbers for all makes and models for specific fireplace
models being proposed. Wood burning fireplaces are not allowed
Show duct chase locations for all multi-story buildings.
All mechanical equipment within vehicular routes shall have
approved vehicle barriers installed. (Bollards)
12. TITLE 24 ENERGY DOCUMENTS - 2 copies required
Provide two (2) copies of the CF-1R compliance forms.
As of July 1, 2014 compliance documents will be required on
New structures and additions over 300 square feet and projects increasing volume of conditioned space.
13. STRUCTURAL CALCULATIONS – 2 copies required
Design for Seismic Zone E/Wind speed 110 mph/Exposure B
Calculations are necessary for retaining walls over 4’, non-standard construction and all one and two-story structures unless meeting single-story framing requirements in the 2013 California Residential Code.
Copies to be wet-signed
14. SPECIAL INSPECTION
Where Special Inspection or Testing is required by C.B.C. Section 1705 the design professional shall incorporate a statement of Special Inspection into the plans. The context of the statement shall include the materials, systems, components, and work to be verified by the registered professional. Such verifications shall be identified as to whether it will be continuous inspection or periodic. Work that is minor in nature for light framed construction, as determined by the Building Official, may be inspected and documented by the engineer of record and shall be made available at the building department’s request.
15. BLUEPRINT FOR A CLEAN BAY GUIDELINE:
Attach 1 copy to 2 sets of plans.
Sheets can be purchased through the City for a fee of $10.00 or
downloaded from City website at www.losaltosca.gov.
16. CIVIL DRAWINGS/GRADING AND DRAINAGE PLAN:
(For new homes and additions over 750 square feet)
Location and elevation of benchmarks
Elevation at street and neighboring property lines
Finished floor elevation(s)
Existing and proposed contours and drainage pattern
Stormwater management measures to retain stormwater on site in accordance with the City’s best Management Practices
Underground utilities – existing and proposed
Note: For additions over 750 square feet the Grading and Drainage Plan shall be prepared by a registered civil engineer or a licensed architect. 17. GREEN BUILDING - 2 copies required (8-1/2 x 11)
All new RESIDENTIAL buildings and existing buildings that increase volume of conditioned space must meet the 2013 California Green Building Standards Code regulations.
All sets of plans shall include a separate full-sized sheet of the cal-green residential mandatory measures form in addition to the two (2) separate 8-1/2 x 11 copies of the form. This form is available at the planning division or at www.losaltosca.gov.
ADDITIONAL INFORMATION & REQUIREMENTS
An automatic residential fire sprinkler system shall be installed in
accordance with National Fire Protection Association’s (FPA) Standard
13D in all new one and two-family dwellings and in existing dwellings when additions are made that increase the building area to more than allowable Fire-Flow Appendix Table B105.1, or additions exceeds fifty (50) percent (inclusive of garage conversions) of the existing living area (existing square foot calculations shall not include existing basement). When automatic fire systems are required by this section, all associated garages shall be included. Tear-downs*/or additions over fifty (50) percent shall be treated as a new structure regarding installation of fire sprinkler systems.
The obligation to provide compliance with these fire sprinkler regulations may not be evaded by performing a series of small additions undertaken over a three-year period. The permit issuance date of past
additions where these regulations were in effect shall be used for determining compliance.
All fire sprinkler plans shall be submitted directly to the Santa Clara County Fire Department by a licensed C-16 fire sprinkler contractor.
The California Water Service requires double check valves installed on buildings equipped with fire sprinklers
*See definition of “Tear Down” under general information.
It is the intent of the city to ensure that all new utility services and
relocated existing utility services are placed underground, including additions and/or Tear Downs* of fifty (50) percent or greater to existing
buildings, excluding basements. Therefore, the following shall apply:
In areas served by existing overhead facilities, all new
service drops shall be installed underground from the
pole designated by P.G. & E.
Relocations and extensions of existing overhead facilities
shall be prohibited; provided, however, relocation of
existing poles shall be permitted in some instances pursuant
to Section 13.20.160 of the Municipal Code.
Residential properties that are served by utilities located in rear yards on standard lots with frontage on only one public right-of-way shall not be required to underground existing overhead services.
The building official may grant exceptions to these require-
ments in cases where access across adjacent property is necessary, but is not legally or practically available.
*See definition of “Tear Down” under General Information.
All properties must be connected to City sewer prior to obtaining a
permit for a new residence or addition to an existing residence.
Contact the Public Works Engineering Division at (650) 947-2780 for
A separate demolition permit is required for the complete and some-
times partial removal of any structure, and must be finalized prior
to the issuance of the building permit. It is recommended that you begin the demolition permit process as early as possible.
The demolition permit application package can be obtained from the
The building division requires a District job number (J#) prior to structural demolition. What is a job number?
Because asbestos has been used in many structural applications, District Regulation 11-2-401.3 requires that for every demolition or for every renovation involving the removal of 100 sq ft./lin ft or greater of Regulated Asbestos Containing Material (RACM), a notification must be made to the BAAQMD at least 10 working days prior to commencement of demolition/renovation. For residential building of four or fewer dwelling units, 72 hour prior notification is acceptable with the payment of an additional fee.
What is the difference between demolition/renovation?
BAAQMD Regulation 11, Rule 2 defines demolition as the wrecking, dismantling or intentional burning of a structure. Renovation is the removal of Regulated Asbestos Containing Material (RACM).