Does modular home need residential building permit?

aquafire

Member
Feb 14, 2024
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We're considering taking the modular home route and having it placed on my father's land. Would we need to get a residential building permit, since it will be a residence?
 
Location
United States
You'll first want to look into your local jurisdiction's zoning requirements for accessory dwelling units (ADUs) to understand what rules govern placement of modular homes in single-family residential (or whatever your father's property is specifically zoned as). @Jake wrote this helpful article on tiny homes/ADUs a little while back, which you may want to check out.

Because of the current housing shortage, it seems like a lot of municipalities have been loosening restrictions on ADUs in order to make it easier for homeowners to provide housing for family or renters. For example, Salt Lake City recently eliminated off-street parking and size requirements for ADUs, which we discussed over in this thread. Note that even if your jurisdiction's zoning laws allow an ADU to be placed on your father's property, you'll still also need a building permit authorizing the modular home structure and work to install it (e.g., plumbing, electrical, etc.).
 
Why would it need a building permit when it's already built? Plus, aren't they inspected by the manufacturer at the plant as part of quality control? I believe you'll need a permit to have it moved, but I can't understand why you'd need the others. In my state, it's only required if you add a deck or other structure to it.
 
Why would it need a building permit when it's already built? Plus, aren't they inspected by the manufacturer at the plant as part of quality control? I believe you'll need a permit to have it moved, but I can't understand why you'd need the others. In my state, it's only required if you add a deck or other structure to it.

Good point, @JoeT. I don't have firsthand experience with this and only know what I've read. I assume they build modular homes with ICC standards in mind but I think some jurisdictions will still want to review and confirm that the design adheres to the nuances of local building code. This probably wouldn't be an issue for jurisdictions that only use ICC building code but might be an issue for other jurisdictions, especially those with building codes geared toward hazard resistance (e.g., southwest states for fire/earthquakes and gulf states for hurricanes). For example, I imagine a modular home being placed in Florida's High Velocity Hurricane Zone wouldn't come factory-equipped with windows able to withstand wind speeds of 195 mph (the requirement for Miami-Dade and Broward Counties). So I imagine some modular homes would have to be retrofitted to meet specific local jurisdiction requirements and that homeowners would need to get building permits for these sorts of modified designs. However, I would think this would only be issue for jurisdictions that deviate from standard design/ICC requirements (e.g., California and Florida).
 
It would need a permit for the foundation and how it would be attached to the foundation. Permits are also needed for the utilities to be ran to the home ( water, gas, elec & sewer).
 
Thanks @Jeff Baughman. I'll just add that in California, where I live, there are a bunch of jurisdictions now offering pre-approved ADU plans that have been reviewed and approved under California Building Code (for example, Monterey County, California). I understand you'd probably still need a permit for the foundation/utility hook-ups, like you pointed out, but I am wondering whether some pre-approved designs cover these sorts of components as well.
 
The pre-approved ADU plans are typically not for manufactured housing and the foundation design would of course need to match the layout of the specific structure.
On a side note, by 1/1/25, all jurisdictions must allow designers/architects to submit plans for pre-approval and they must be available on the City's website.
 
The pre-approved ADU plans are typically not for manufactured housing and the foundation design would of course need to match the layout of the specific structure.

Thanks for clarifying this. You're right, @aquafire was specifically asking about modular homes. It sounds like pre-approval probably wouldn't be an option in that case.

On a side note, by 1/1/25, all jurisdictions must allow designers/architects to submit plans for pre-approval and they must be available on the City's website.

Hadn't heard about this, thanks for sharing. I assume you're talking about a new state-level law going into effect in California? Sounds like this will increase workload for building departments in the short-term but will produce long-term efficiencies by giving homebuilders a larger selection of pre-approved options. I'm sure that's the idea anyways.
 
It would need a permit for the foundation and how it would be attached to the foundation. Permits are also needed for the utilities to be ran to the home ( water, gas, elec & sewer).
This seems like the right answer to me. Since it's already built, they may need to file a permit to move it, but they would also need to have a foundation in place, which means a permit for that. Especially the connections. You may also need to hire an electrician to handle the electricity as well.

I don't see a need for a building permit unless they need to do other work to the home.
 
Yes, even if you're considering building a modular home on your father's land, you would typically still need to obtain a residential building permit. Regulations regarding permits for modular homes vary depending on the location and local building codes. You did not mention your exact location, therefore, I cannot provide exact process, so you should check with the local building department or permitting office to understand the specific requirements and ensure compliance with all regulations before proceeding with your project.
 
Any new structure that is being placed on a property as a residence needs to be approved by the jurisdiction. Most places it's called a "placement permit". It includes review of the foundation, connections to utilities, driveway, fire access, and addressing. They also verify the lot is legal to have a dwelling on, and what the allowed density is. Many farm, commercial and industrial zones don't allow single-family detached residence or residential at all.
 
It would need a permit for the foundation and how it would be attached to the foundation. Permits are also needed for the utilities to be ran to the home ( water, gas, elec & sewer).
Agree with Jeff, plans and permits for foundation and utilities. Always check with your local jurisdiction as they may have other conditions that need to be met.
 
Thanks @Jeff Baughman. I'll just add that in California, where I live, there are a bunch of jurisdictions now offering pre-approved ADU plans that have been reviewed and approved under California Building Code (for example, Monterey County, California). I understand you'd probably still need a permit for the foundation/utility hook-ups, like you pointed out, but I am wondering whether some pre-approved designs cover these sorts of components as well.
City of Medford, Oregon also has pre-approved ADU plans available on our website.
 
They also verify the lot is legal to have a dwelling on, and what the allowed density is. Many farm, commercial and industrial zones don't allow single-family detached residence or residential at all.

Good point - I think zoning restrictions probably do have the biggest effect on ADU availability. Pre-approved ADU plans are only as good as people's ability to build where they want to, right?

One exception to the rule is Anchorage, Alaska. Last year they began allowing ADUs in commercial zones and on multifamily properties, not just in areas zoned for single-family (as was previously the case). A real estate broker interviewed in this article praised the fact that they'd now be able to convert old garages and storage areas to housing thanks to the zoning reforms. Goes to show how much untapped potential for additional housing/ADUs there really is, depending how far jurisdictions are willing to go loosening restrictions.
 
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