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site-built, mobile/manufactured and modular homes

Does an addition to a mobile home have to comply with the HUD Code?

Wednesday, October 3, 2018

The HUD construction standards apply to the manufacture of a mobile home up until it has been inspected and approved by an In-Plant Primary Inspection Agency (IPIA), receives a HUD sticker, and heads down the highway for delivery. After that, there are still some HUD Code standards for installation of the home at its final destination but, once the home is sited, HUD’s jurisdiction ends.

   Any additions or repairs to a mobile/manufactured home only have to comply with local building codes. But there are several important issues to consider when adding to a manufactured home:

1) The exterior wall of a HUD Code home is only engineered to support its own roof structure. The photo above shows the roof structure of an addition that bears on the fascia of a mobile home—which is not allowed and puts additional weight on a manufactured home wall that was not designed to carry it. Any addition should be self-supporting, unless a “host beam” has been installed at the factory for the future addition. See our blog post What is a "host beam" at a mobile/manufactured home? for more on this.

2) A manufactured home needs two unobstructed exterior doors for emergency exit in a fire. An addition that eliminates or obstructs direct access to one of the exit doors is a safety hazard. The HUD code also requires these two safety features for exit doors:
        a) Shall not be located in rooms where a lockable interior door must be used in order to exit. [24 CFR 3280.105(a)(1)]
        b) One of the required exit doors must be accessible from the doorway of each bedroom without traveling more 35 feet [24 CFR 3280.105(a)(2)(iv)]

3) The crawl space under a mobile home needs to have ventilation openings. If an addition eliminates a significant area of vented skirting and reduces the cross-ventilation air flow under the home, the buildup of moist air in the crawl space can cause mold problems in the home over time, especially if the bottom board (also called the “belly wrap”) is no longer intact.

4) If your home is still within the manufacturer’s warranty period, an addition may void the warranty. Check your warranty paperwork.

5) If you decide to relocate your home, the addition complicates the move. It cannot be moved and will require demolition. Also, any openings in the exterior of the home cut for the addition will have to be repaired, and plumbing and electrical wiring restored to their original configuration.    

    Go to our HUD-CODE FOR MOBILE HOMES page for a listing of our other HUD-code articles. Also, see our blog posts What walls can I remove in a mobile home? and What do I need to know about building an addition to a mobile home? 

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Want to learn more about inspecting
manufactured/mobile homes? 
Get our  Handbook for 
Manufactured Home Inspectors 
at for $19.95

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Here’s links to a collection of our blog posts about MOBILE/MANUFACTURED HOMES:

Where can I file a complaint if I have problems with my new or used manufactured/mobile home in Florida?

 What are the most common defects in mobile/manufactured home foundation piers?

How do I determine the age of a very old mobile home?

What is a "HUD label verification letter" for a mobile/manufactured home?  

When did a ground cover vapor barrier (plastic sheet) become required under a mobile/manufactured home? 

Is it safe to go under a mobile home? 

Are older mobile homes unsafe? 

What do I need to know about buying a foreclosed mobile home? 

Does it make sense to buy an older mobile home and remodel it? 

Where do I find the vehicle identification number (VIN) on a mobile home? 

How do I find out how old a mobile home is and who manufactured it?

What is the right price for a used mobile home?

How energy efficient is a mobile home?

When were the first double-wide mobile homes manufactured?

How do I upgrade my old (pre-1976) mobile home to meet HUD standards?

What size air conditioner is right for my mobile home? 

Can you move an older mobile home in Florida? 

What does the HUD tag look like and where do I find it on a mobile home? 

Can you put a zone 1 mobile home in Florida?

How can I remove water under my mobile home?

What's the differences between a trailer, a mobile home, a manufactured home, and a modular home? 

What is a D-sticker mobile home? 

What are the tie-down requirements for a mobile home?

How fireproof is a mobile home?  

Can I install a mobile home myself?

What is a Park Model mobile home?  

Does an addition to a mobile home have to comply with the HUD Code? 

What walls can I remove in a mobile home?

What can I do to prevent dampness and mold in my mobile home? 

How can I tell if a mobile home is well constructed?

How can I tell the difference between a manufactured home and a modular home?

       Visit our MOBILE/MANUFACTURED HOMES  page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

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