Modular Homes – A Permanent Structure Or Not?

Modular homes are treated just like any traditional site built house and are therefore considered permanent structures without exception, once a modular home is built on site it can’t be transported to a different location. Yet, since modular homes are built off-site it is common to compare them to a more widely known prefabricated structure: the manufactured home. 

However, manufactured homes are non-permanent structures and despite the building process, modular homes share more similarities to site-built constructions. Both permanent and non-permanent structures adhere to strict building regulations, though the permits and documents hold by these two are not the same.

Modular homes will never hold:

  • Certification label or HUD tag
  • VIN or serial number
  • Data plate
  • Title or Deed

While there are some exceptions where it is possible to see the term modular associated to a non-permanent structure, that structure will never be a modular home.

We can encounter non-permanent modular constructions as relocatable buildings such as classrooms, emergency shelters, showrooms or temporary healthcare clinics. These structures are tagged as modular because they are built following the modular technique, though do not get confused: modular homes are always permanent.

The difference between a non-permanent and a permanent house

A non-permanent house is a structure built with the main purpose of being mobile, just as mobile homes or its updated version: the manufactured home. While certainly these constructions are often purchased as a substitute for a traditional house and will remain in the same location for most of their life, they are still built as a mobile structure. 

The whole house is always constructed on a permanent fixed steel chassis designed not only to stabilize the house but to attach it to the wheels during transportation since a non-permanent house can be moved to a different location at any time.

Because they are moveable, it is possible to place them in any desired location independently on where they have been built or placed for the first time. Therefore, it makes no sense to build these houses up to the regulations of one particular location. However, to ensure the safety of its occupants, the Manufactured Home Construction and Safety Standards has designed the HUD Code [1], a code applicable nationwide that not only obliges manufacturers to follow certain rules but to indicate the limitations of each construction.

A permanent house is a structure that is designed to be constructed on one particular location and will be built on permanent foundations without considering the possibility of transporting the whole house to a different location at any time. Modular homes, even if constructed off-site, will be assembled on permanent foundations. 

The prefabrication process required to build permanent structures is quite different from non-permanent homes since while non-permanent homes are completely finished once leaving the factory, permanent homes won’t be finished until assembled on site and attached to their foundation. After the in-factory construction, a modular home is at most 80% finished [2]  and will still require some site works to be ready to be lived in.

Permanent constructions are required to follow all the building regulations dictated by the state, county and town from where the house is going to be permanently placed. Even if most of the construction process of a modular home takes place off-site, it will never be built up to standardized national code and will always adapt to the regulations dictated by the location where the house will be permanently assembled.

Permits and documents held by Modular homes

Permanent constructions don’t need to hold a lot of documents once built because to be constructed they have had to go through a process of paperwork acceptance. However, in order to start building as well as to move in it is required to obtain some permits.

Building permit on permanent buildings

Every permanent house is required to obtain a building permit before construction starts and modular homes are no exception to this rule, the manufacturing process will only start once the building permit has been accepted.

To obtain the Building permit you should first collect all the necessary requirements to ensure your design follows the guidelines stablished the city’s development. In most cases this information can be found online but it is recommended to contact the Architectural Review Commission as well as the Planning Commission to discuss the project and ease the acceptance process [3].

To apply for a building permit, it is required to submitting all the necessary information regarding the project to the Building & Safety Division of the City’s Community Development Department [3]. While the required documents will vary depending on your location they usually include: 

  • Application forms
  • House design plans
  • Technical plans such as structural drawings or soil information.
  • Builder’s information.

The Building & Safety Division will review all the submitted document and if there is no mismatch between the requirements and your home’s designs, they will approve your request, issue the building permit and construction can begin. 

Certificate of occupancy

Before you can move into your newly constructed house, it is required to hold the certificate of occupancy (CO). Once the house is build and assembled on site the Building & Safety Division staff will undertake an on-site visit to perform a final inspection the objective of which is to verify that all the building codes have been properly met and the building is safe to be lived in. Usually the most important aspects reviewed during this inspection are:

  • Electrical installations
  • Plumbing systems
  • Handicap accessibility

If everything is working correctly and built in accordance with the technical codes the certificate of occupancy is handed and you can move in [4].

Real estate title or property title or deed

A real estate title is the legal document that certifies the ownership of that property and it is a very important document because it defines who holds the legal rights, control and responsibility over that property. The title however is not a legal document but a concept. In the moment of selling or changing the ownership details that a document is needed and the legal document in which the title is transferred is called a deed [5]. 

Documents hold by non-permanent homes

Non-permanent homes follow a very different process in relation to permits and documents, contrary to permanent constructions they can be manufactured without knowing where will they be placed and state and local building permits are not required. However, in order to verify the safety of the structure non-permanent houses adhere to the HUD codes and are expected to hold.

Certification label or HUD tag 

The certification label, also known as HUD tag is a red metallic plate of 2×4 inches (5×10 cm) that is visibly placed on the exterior of the home and certifies that the house has been inspected by the U.S. Department of Housing and Urban Development before leaving the factory and is build up to the HUD code [6]. This plate must contain the certification label number consisting on a series of 3 letters and 6 numbers [7] stamped on it in silver color. 

Data Plate house document

The Data Plate is a very important document that despite its name, it is not a plate but a piece of paper containing all the detailed information about the house. The most important information enclosed in this document includes:

  • Manufacturer’s details
  • Date of construction 
  • Serial or VIN number 
  • Model number 
  • HUD label number
  • Safety information such as the maximum load the roof can tolerate or the amount of wind it can withstand [7].

This document needs to remain in the house permanently since its absence might keep you from financing, selling, improving or repairing your home [6], and it is usually affixed inside a cabinet, closet or electrical panel.

Serial or VIN number as identification

The serial number is the house identification number showing various details about the house such as the manufacturer and the state in which it has been manufactured. Every mobile house has a different number assigned that is displayed in both the steel chassis and the Data Plate. This number is also used to register the house when placed for long periods of time in the same location.

It is also referred to as VIN number (vehicle identification number) since until 1976 these constructions where classified as vehicles and their identification number was issued by the Department of Motor Vehicles, not the HUD [7]. Today, theU.S. Department of Housing and Urban Development only issues serial numbers, though users still refer to it as VIN number.

Title held by a permanent house

The title held by a non-permanent house is quite different from the title held by a permanent house since a non-permanent house isn’t considered real estate property but personal property. Mobile and manufactured homes are treated as personal property since they are seen more like an automobile than a site built house [8]. 

The title, just as with permanent constructions, is used to prove the ownership of the house, though it only accredits the ownership of the house alone and will never include the land since it is not a real estate property title.

Modular homes are always permanent structures

The modular technique is an advanced construction solution that follows an industrialized process to build sections or modules that fit in a truck. These sections are therefore easily transportable and once on place require almost no construction work to be fully functioning, which represents a great advantage and is therefore used in different situations.  

Projects such as emergency shelters and temporary health care dispensaries are relocatable buildings that require a fast building process with minimal disruption, the modular technique is a great solution for this cases and though these constructions are considered non-permanent they follow the state and local building codes [9] to ensure their safety, just as any permanent construction. 

Any house labeled as a “Modular home” will always be built as a permanent structure and should at no time be referred to as a synonym for manufactured or a mobile home. Certainly there are some exceptions in which some modular structures are considered non-permanent, though these are never modular homes.


  1. Manufactured Home Construction and Safety Standards U.S. Department of Housing and Urban Development
  2. Turn Key and Custom Modular Homes West Built Homes
  3. A customer guide to the building permit process Government of City of San Luis Obispo, California – Building & Safety Division
  4. Certificate of Occupancy/ Completion Government of City of North Miami Beach, Florida – Building Department
  5. (2017, August) What is the Difference Between a Title and a Deed? Atlantic Bay Mortgage Group
  6. Adkins C. (2019, 14 September) Manufactured Home HUD Tags, Labels, Serial Numbers, and Data Plates Mobile Home Living
  7. Missing HUD Labels (Tags) Manufactured Housing & Standards U.S. Department of Housing and Urban Development
  8. (2018, 22 April) Why would manufactured homes require a title? Jacksonville – The Florida Times-Union
  9. (2018, March 1) Permanent vs. Non-permanent modular construction FRAMECAD