New Mobilehome and Special Occupancy (RV) Park Construction Requirements
Below are requirements for new park construction. Visit the Mobilehome Park Forms page to download the necessary forms for use in park construction or alteration. Refer to the Park Construction Approval Booklet, HCD MP 514 (PDF) for additional information about your park construction process. For information on mobilehome / manufactured home alterations, please visit the Modifying a Mobilehome page.
Required Local Government and Utility Agency Approvals
A construction permit is required when developing a new mobilehome park or special occupancy park or constructing additional spaces and/or facilities within an existing park. The following local government approvals and utility agency "will serve" letters must accompany all park construction project permit applications:
- Written approval or a conditional use permit from the local planning agency [Health and Safety Code Section 18501(e)].
- Environmental impact reports, recommendations, and approval from the reviewing agency, normally the local planning department [Title 25, California Code of Regulations, Section 1030] .
- Permit from the Coastal Commission for developments within the permit area of a coastal zone.
- Written approval or stamp of approval from the local health department on all plans relating to water supply and method of sewage disposal [Health and Safety Code Section 18501(e) ].
- Written approval or stamp of approval on all plans relating to fire protection provided in the mobilehome park from the local fire department [Health and Safety Code Section 18501(e) and Title 25, California Code of Regulations, Section 1032 ].
- Written approval or stamp of approval on all plans relating to the park surface or subsurface drainage systems from the local public works department, engineering department, flood control agency, or water quality control board [Health and Safety Code Section 18501(e) ].
- Contact local water agencies and public utilities for availability of planned services. Provide letters stating services will be provided. [Health and Safety Code Section 18501(e) ].
Note: The required written approvals may be in letter form issued by the agency having authority to grant such an approval or simply a signature on the affected plans by the approving agency's authorized agent.
Plan(s) must be drawn to scale on substantial paper or cloth and be of sufficient clarity to indicate the nature and extent of the construction proposed. Provide detailed plan(s) conforming to the provisions of the Title 25, California Code of Regulations, Chapter 2 , and all applicable laws, ordinances, rules, and regulations. The first sheet of each set of plans must give the location of the proposed construction, name and address of the owner, and name of the person preparing the plans. The plans must include all required information listed on the pages linked to our Park Construction Requirements page.
Plot Plans must include the following information:
- Site location with north arrow.
- Address of proposed construction or reconstruction.
- Name and address of owner(s).
- Name and address of person(s) preparing plans.
- Index of sheets on title sheet.
- All required local approvals, Environmental Impact Report, or negative declaration.
- The identification of all property lines, adjacent property lines, and mobilehome/R.V. lot lines.
- Dimensions of all mobilehome/R.V. lots.
- Method of permanent lot line identification including corner markers, lot numbers, and/or other means of identification.
- Easements and/or right-of-ways, public or private, if any.
- Location and size of all permanent buildings, parking spaces, and storage areas.
- Schedule of manufactured/mobilehome size for individual lots.
- Roadway widths and location of no parking signs.
Drainage and grading plans must include the following information:
- General vicinity map of the proposed site.
- Property limits and accurate contours of existing ground, details of terrain, and area drainage.
- Limiting dimensions, elevations, or finish contours achieved by grading, proposed drainage channels, or other related construction.
- Detailed plans of all surface and subsurface drainage devices, walls, cribbing, dams and other protective devices constructed with, or as part of, the construction, and a map indicating drainage area(s) and estimated runoff of the area served by any drains.
- Location of buildings or structures on the property where the construction is to be performed. Identify location of any buildings or structures on property of adjacent owners which are within 15 feet of property, or that may be affected by proposed grading operations.
Grading notes must be shown on plans:
- Include soils report with the plans.
- Grading practices must comply with Chapter 70 of the 1985 Uniform Building Code.
- The design engineer must provide a letter upon completion of the grading, certifying that the final grades are in compliance with the approved plans.
- The soils engineering firm must conduct field observations and tests during construction to verify the quality of the work, conformance to the specifications, and recommendations contained in the soils report.
- Upon completion of the grading, the soils engineer must submit a final report including test results, certifying the construction is in compliance with the specifications/plan(s) and recommendations contained in the soils report.
The Soil and Engineering Report must include the following:
- Data regarding the nature, distribution, and strength of existing soils, and conclusions.
- Recommendations for grading procedures.
- Design criteria for corrective measures, if necessary, must be included in the report.
- The report must provide recommendations, if any, covering adequacy of sites to be developed by the grading.
- Recommendations included in the report and approved by the building official must be incorporated in the grading plans or specifications.
The Engineering Geology Report must include the following:
- An adequate description of the geology of the site.
- Conclusions and recommendations regarding the effect of geologic conditions on the proposed development.
- Options and recommendations covering the adequacy of sites to be developed by the proposed grading.
- Recommendations included in the report must be incorporated in the grading plans or specifications.
Detail on the Utility Trenches must include the following:
- Location of all utility trenches.
- Depth of trenches.
- Width of trenches.
- Location and spacing of utilities within trenches.
- Types of bedding and covering for utilities.
- Protection and backfill of trenches.
Fire Protection Plans must include at least the following information:
- Location of fire hydrants.
- Type and manufacturer of hydrants.
- Location and type of shutoff valve(s).
- Location of thrust block size schedule.
- Water flow duration time, gallons per minute (expressed as GPM), and required pressure.
- Approval signature of local fire protection agency for fire protection provisions. Include with the approval, duration time, GPM, and required pressure data.
Electrical Distribution System/electrical plans/electrical calculations must include the following specifications:
- Specifications of park service equipment and manufacturer.
- Specification of the voltage, ampere and interrupting capacity rating, type and class of the overcurrent protective device in the park service equipment,
- Ambient temperature design based on Title 25, California Code of Regulations, Chapter 2, Section 1142 .
- Specify voltage, ampere, and interrupting capacity rating, type and class of overcurrent protective device for the primary system feeders and/or transformers.
- Specify type of conductors, i.e., CU or AL; type of insulation; voltage rating; and temperature rating.
- Provide specifications for transformers and unit substations.
- Specify primary and secondary voltages, KVA ratings, and impedance of transformers.
- Provide specifications for secondary distribution panel boards or that portion of the unit substations.
- Specify voltage, ampere and interrupting capacity rating, type and class of the overcurrent protective devices for the secondary system feeders.
- If the system is installed or owned by a utility company, provide a letter confirming such service, including information regarding the point of termination.
- Complete electrical specifications, plans, and calculations are required if the point of termination does not comply with Title 25, California Code of Regulations, Chapter 2, Section 1184 .
Electrical Plan details must include the following:
- Single line diagram of park electrical system, including the park lighting system.
- Indication of location(s) of all equipment devices and conductors in the system.
- Indication of circuit length, conductor size, and distance to center of load.
- Details of conduit installation and size.
- Details of conductor installation.
- Details of equipment installation and mechanical protective barriers, if required.
- Details of correct method of grounding system and equipment.
- Details of park lighting installations.
- For systems exceeding 230 volts, the signature of a California registered engineer.
Electrical Distribution System plan calculation details must include the following:
- Load calculations for all loads served, not to exceed a total combined voltage drop of 5 percent for any total run.
- All buildings in load calculations.
- Written evidence from the serving utility indicating the available fault current at the park service. (See Required Local Government and Utility Agency Approvals above.)
- Calculations utilized to determine interrupting capacity of overcurrent protective devices for each transformer.
- Calculations used to determine interrupting capacity of overcurrent protective devices for secondary system feeders.
- Park lighting calculations to verify compliance with Title 25, California Code of Regulations, Chapter 2, Section 1108 .
- For systems exceeding 230 volts, the signature of a California registered electrical engineer.
Sewage Disposal System plans must include at least the following information:
- If applicable, details of location and design of private sewage disposal system, including sizes of tanks, distribution boxes, and drain fields.
- A signature of approval from the local health department must be on plans. (See Required Local Government and Utility Agency Approvals above.)
- Size, length, and grade of sewer lines.
- Type of pipe, manufacturer and pipe identification numbers, fittings, and location of pipe.
- Location of cleanouts and vents.
- Details of lot risers, p-traps (if any), venting, and protection of traps, mobilehome connection details.
- Location of sewer inlet on mobilehome lot.
- Engineered structural design and calculations for any on-site construction of septic tanks and/or sewage lift stations. The signature of the responsible California registered engineer must be on the calculations.
- Design of required sanitary dump station if any lots are not provided with sewer and water utilities.
- Signature and stamp of professional engineer if system is in excess of 100 mobilehome lots.
- Location and connection to public sewer system.
- Signature and stamp of professional engineer when grades of the system are less than specified in Section 1268 (b), or if park drainage system exceeds the fixture unit loading of Title 25, California Code or Regulations, Chapter 2, Section 1268, Table 1292-1.
- A letter from the design engineer stating he/she verified grade of all sewer lines on the construction site must be submitted after installation and will provide the enforcement agency with evidence indicating the grade of the lines was inspected.
- If applicable, design, construction, and installation of sanitary sewer lift stations and pressure lines. Include pump specifications, gate and back flow valves, engineered calculations for the force main and venting, and audio visual alarm systems.
The Water Distribution System plans must include at least the following information:
- If applicable, source and pressure of private water system and letter of approval from local health department. (See Required Local Government and Utility Agency Approvals above.)
- Source of water and pressure at source of water if from a public water district.
- Type of pipe, manufacturer, pipe identification numbers, fittings, and location of pipe.
- Location of connection to source, meter size, check valves (if required), pressure reducing valves (if required), pipe sizes, fittings, type, and material of pipe and fittings.
- Details of service riser to each lot, size, material, valves, backflow preventers, and mechanical barrier protection if required.
- For additions to existing systems, include psi at point of interconnection at system and size of water main at that point.
- Water demand calculations.
- Thrust block schedule per Uniform Plumbing Code, 1985 edition.
- A complete single line diagram of the new and existing system.
- Locations of service risers for each lot.
- Water distribution system designed in accordance with 1979 Uniform Plumbing Code, Chapter 10, and Appendix A.
The gas distribution system plans must contain at least the following information:
- If system is installed by a utility company, letter confirming such service and identification of point of termination. (See Required Local Government and Utility Agency Approvals above.)
- Indication of source of gas supply and pressure.
- Calculations for demand and pipe sizes (Title 25, California Code of Regulations, Chapter 2, Section 1230 ).
- Length of gas piping system runs, location of runs and shutoff valves in runs, showing size transition locations in runs. If adding to an existing system, complete demand calculations with a single diagram of the existing and proposed system.
- BTU demands of piping system.
- Schedule of pipe size, manufacturer, and identification of numbers of pipe, protective coating, wrapping of joints, and method of assembly.
- Detail of mobilehome lot service riser, wrapping, type, manufacturer of gas shutoff valve, regulator and/or meter installation, supports, location, and protective barrier, if required.
- If system is Liquefied Petroleum Gas (LPG), indication of location and size of tank(s). LPG systems must comply with Title 25, California Code of Regulations, Chapter 2, Section 1210 .
- If gas system is over eleven (11) inches, water column system must be designed by a professional engineer in compliance with Federal Regulations by installation of a cathodic protection system (Title 25, California Code of Regulations, Chapter 2, Section 1206 ). A report indicating evidence of compliance with Title 49, Code of Federal Regulations, Parts 191 and 192, and Title 25, California Code of Regulations, Chapter 2, Section 1206 , must be provided by a qualified person prior to final approval of the gas system.
- Permanent buildings must be on a separate set of plans.
- Permanent building must comply with Title 25, California Code of Regulations, Article 8 .
- Public swimming pools constructed within a park must comply with the requirements of Title 17, California Code of Regulations, Section 30740 .
Forms and Publications
- HCD MP 50 - Application for Permit to Construct (PDF)
- HCD MP 511 - Application for Alternate Approval (PDF)
- HCD MP 514 - Park Construction Approval Booklet (PDF)
- HCD MH 415 - Manufactured Housing Permit Application (PDF)
This form can be submitted to the Department via email to:
Exception: HCD does not accept large format plans via email. These plans must be submitted by mail or in person.
When submitted to HCD, the completed application must be accompanied by the appropriate fees. Payment must be in the form of a check or money order payable to the Department of Housing and Community Development. Payments can also be submitted through the Department’s online fee-payment system. Please note: you must have a DTN and a zip code to make a payment online. This information can be obtained by contacting the appropriate Area Office at (800) 952-8356 or NAOstaff@hcd.ca.gov or SAOstaff@hcd.ca.gov.
This form can be submitted to the Department via email to:
Exception: HCD does not accept large format plans via email. These plans must be submitted by mail or in person.
When submitted to HCD, the completed application must be accompanied by the appropriate fees. Payment must be in the form of a check or money order payable to the Department of Housing and Community Development. Payments can also be submitted through the Department’s online fee-payment system. Please note: you must have a DTN and a zip code to make a payment online. This information can be obtained by contacting the appropriate Area Office at (800) 952-8356 or NAOStaff@hcd.ca.gov or SAOStaff@hcd.ca.gov.
Alterations to Existing Parks
Before making alterations to an existing park, check the requirements for such alterations. Visit to the Alterations to Existing Parks page for more information.
Please contact either our Northern Area office or Southern Area office at (800) 952-8356 to obtain additional information concerning plan and permit requirements.
Check Information Bulletins frequently for additional information pertaining to mobilehome park and special occupancy park construction.
For park construction information in Wildland Urban Interface (WUI) Areas, consult the standards, regulations and information.