Foundation Certifications Submit Online
Home        Home
Call us at 817-585-2585

In order to view this object you need Flash Player 9+ support!

Get Adobe Flash player

Mobile Home Plans
Frequently Asked Questions (FAQs)

Below are some answers to frequently asked questions for our FHA, HUD, and VA mobile home foundation plans. If you can not find you answer here, please also go to our Glossary of Terms and Definitions page.








What is the process for filing and recording a 433a in California?

In general terms, the process is as follows:

  1. Our inspector will perform an on-site inspection of your mobile home foundation.

  2. The Engineer will write a report certifying that your mobile home is on a permanent foundation system. If your home is certified by the engineer, then proceed to Step 3, below.

    If your home is not on a permanent foundation as determined by the engineer, then you may be required to install a retrofit to bring it up to standards. To be on a permanent foundation system, you must proceed with one of the two approaches below; the engineer may recommend which approach will be more economical:

    • The Pre-Approved Foundation System (Proprietary) Approach.

      In this approach, the mobile home foundation must be installed with a state pre-approved permanent foundation system with proprietary components. The State of California updates their list of pre-approved permanent foundation systems every two years. The manufacturers of different permanent foundation systems must apply to the State of California to have their foundation systems included in the state's pre-approved list. Their application package must include an Engineer's Stamped set of Plans, drawings, and test data of their proposed permanent foundation system. If the manufacturer's application is accepted by the state, then they are included in the pre-approved foundation system list.

      This approach includes...

      • Hiring a contractor
      • The contractor applying for an installation permit for a permanent foundation system.
      • Installing a pre-approved foundation system; this is also called a retrofit.


    • The Site-Specific Engineered System Approach.

      In this approach, the engineer provides a set of site specific engineer foundation plans for the home. The engineer does not necessarily have to use any items from the pre-approved list available from the state. Many times the engineer can provide a more economical approach rather than having a contractor install a pre-approved foundation system.

      This approach includes...

      • Creating engineered foundation drawings. If it is a new manufactured home on a new foundation, then we will provide the new plans and specifications needed for the contractor. If it is an older manufactured home on an existing foundation, then an our engineer will need to create a set of "Record Drawings" (also called "As-Built Drawings") to be turned into the building department at the time of the application for the 433a,
      • If required, a list of items that may need to be installed as a retrofit.
      • Installing any retrofit items as required by the engineer.


    Prior to the installation of any retrofit on the manufactured home whether it be a Pre-Approved System or a Site-Specific Engineered System, the owner or a licensed contractor shall obtain a building permit from the appropriate enforcement agency (city, county, etc.). To obtain a permit, the owner or contractor shall first provide the following:

    • Written evidence that owner owns, holds title to, or is purchasing the real property where the mobilehome is to be installed on a foundation system.
    • Written evidence acceptable to the enforcement agency that the registered owner owns the manufactured home.
    • Applicable permitting fees.


  3. Complete the 433a form. To see who fills this out, see the FAQ below on "Who completes California Form 433a?"

  4. Inspection by the governing building department. This is the 513C process (see FAQ below). This is after the Engineer certifies the foundation, and the 433a is applied for. Sometimes, the local building department will require Site-Specific Engineered Drawings if a Pre-Approved system is not installed on the home.

  5. Finally, the 433a document is recorded at the County Recorder's Office.

         ^ top














Home | Services | About Us | Contact Us | Site Usage and Terms & Conditions | Sitemap

Copyright © 2017
In North Carolina, all projects are performed by Harrison Engineering Services PLLC our affiliated company.
In Montana, all projects are performed by Harrison Engineering Services our affiliated company.


Member of ASCE FHA HUD Member of SEI