Modifying a Mobilehome or Manufactured Home: 
Alteration, Permit Requirements, and Inspections

Before beginning any work on your mobilehome, manufactured home, commercial modular, special purpose commercial modular or multifamily manufactured home you must submit an application for a permit (form HCD MH 415).

Note: Form HCD MH 415 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 or

The Department must review and approve plans and specifications for the alteration or conversion of manufactured homes, multifamily manufactured homes, commercial modulars, and special purpose commercial modulars.  Department employees perform on-site inspections of alterations and conversions to the structural, fire safety, plumbing, mechanical, and electrical systems of regulated units.

Approved Plans

To review all requirements for submission of the listed forms or plans and their associated fees please review the appropriate section of the Mobilehome Parks and Installations regulations  or Special Occupancy Parks regulations .

These plans and specifications have been preapproved by the Department. They are valid for the purpose of obtaining a construction permit when the design loads and allowable soil conditions specified in the plans are consistent with the requirements for the locality. Any alteration to a plan without Department approval will render the plan invalid.


Fees will be charged for these preliminary plan check meetings as a technical service fee ($196.00 per hour, $196.00 minimum).


Mobilehome Assistance Center (Complaint Forms)

Permits & Inspections

If any of the following changes have been performed without a valid permit, you are encouraged to obtain a permit prior to the Department's inspection in order to avoid possible penalties:

Installation, construction, or alteration of:

  1. Any mobilehome, building, structure, or accessory building;
  2. Any electrical, mechanical, or plumbing equipment;
  3. Any fuel gas equipment;
  4. Any fire protection equipment within the unit.

Information Bulletins

Check Information Bulletins frequently for additional information pertaining to modifying a manufactured home/mobilehome.