If you are buying or selling a manufactured home in California, sooner or later someone may ask whether the property has a "433A" or, less directly, whether the home is on a “permanent foundation.” Unfortunately, the term "permanent foundation" is often used loosely and can create confusion. How a manufactured home is physically installed and anchored to its foundation is one subject. Whether it has been installed and documented under the 433A process—and therefore treated as a fixture or improvement to the real property—is another completely separate subject.

What Is a 433A?

Form HCD 433A, issued by the California Department of Housing and Community Development (HCD), is formally called the Notice of Manufactured Home, Mobilehome, or Commercial Modular Installation on a Foundation System. It is used when a manufactured home is installed on an approved foundation system as a fixture or improvement to the underlying real property under California Health and Safety Code §18551(a).

The installation is permitted and inspected by the appropriate enforcement agency. After approval and issuance of a Certificate of Occupancy, the 433A is recorded with the county recorder. The recorded document provides legal notice that the manufactured home has become a fixture or improvement to the real property, rather than remaining separately titled personal property. HCD's title record is then changed accordingly.

These distinctions can be important to lenders, title companies, appraisers, buyers, sellers, and taxing authorities.

Does Every California Manufactured Home Need a 433A?

No. California law allows manufactured homes to exist as personal property as well as real property. Many manufactured homes have been legally installed for decades while remaining separately titled through HCD.

The absence of a recorded 433A does not, by itself, mean that the home was improperly installed or that there is something physically wrong with its foundation. A 433A is used when the manufactured home is installed on an approved foundation system as a fixture or improvement to the underlying real property under California Health and Safety Code §18551(a).

California law even recognizes that a manufactured home can be installed on a foundation system while remaining chattel, or personal property. That is an important distinction: being attached to a foundation and being legally part of the real estate are not the same thing.

The Confusing Term: “Permanent Foundation”

Much of the confusion comes from the phrase "permanent foundation." In ordinary construction terminology, most people hear “permanent foundation” and imagine a traditional poured-concrete or masonry perimeter foundation similar to the foundation beneath a site-built house. In manufactured-housing, real-estate, and lending discussions, however, the term is also commonly used to describe the home's legal status.

California HCD itself uses “permanent foundation” in some contexts to describe a manufactured home installed on a foundation system as a fixture or improvement to the underlying real property, inspected and approved by the building official, with the 433A recorded. This is where much of the confusion originates. In construction and inspection terminology, “permanent foundation” may describe a physical foundation configuration. In California real-estate and lending terminology, the same words may instead refer to the home's legal status.

Standard Set Versus Permanent Set

For inspection purposes, manufactured-home installations are commonly described nationally using two broad physical configuration types:

1. Standard Set. A Standard Set manufactured home is typically supported beneath its structural frame by piers. These may include concrete masonry piers, manufactured metal supports, or other approved components. Footings or pads transfer the loads to the soil. The manufactured home also requires an anchoring or bracing system to resist forces such as wind and earthquakes.

Because the piers and underside of the manufactured home would otherwise remain exposed, a nonstructural enclosure or skirting is commonly installed around the perimeter. Skirting may be constructed from numerous materials, including manufactured panels, metal, masonry, wood products, or other materials.

The important point is that the skirting normally is not the foundation. The manufactured home's structural loads are generally being carried by the piers and supporting system behind it.

2. Permanent Set. With what inspectors commonly describe as a Permanent Set, the manufactured home is installed over a foundation more closely resembling that of a conventional site-built house. There may be a poured-concrete or reinforced-masonry perimeter foundation supported by concrete footings, creating a conventional crawlspace or sometimes a basement.

Interior supports or piers are still commonly necessary because manufactured homes are generally designed to carry substantial loads through their steel chassis or other designated structural support locations. The home is then structurally connected or anchored to the foundation system. Because the perimeter foundation itself encloses the crawlspace, separate decorative skirting is generally unnecessary.

What About the Hitch, Axles and Wheels?

Another common misconception is that a manufactured home becomes real estate once the wheels, axles, or towing equipment have been removed. It isn't that simple.

Manufactured homes are designed and built for transportation to their installation site. Removing transportation components may be part of an installation, but the presence or absence of those components does not, by itself, establish whether the home is legally personal property or real estate.

Likewise, seeing an old hitch beneath a manufactured home does not establish that there is no 433A. The presence or absence of transportation components does not determine the home's legal property status; that status must be established from the appropriate records.

Can a Home Inspector Determine Whether a Manufactured Home Has a 433A?

No. A home inspector can inspect the visible physical condition of the manufactured home's foundation and support system. Depending upon accessibility and the scope of the inspection, that can include observations involving:

• piers and supports;
• foundation walls and footings;
• anchoring or bracing components;
• visible deterioration or damage;
• improper or displaced supports;
• crawlspace conditions; and
• other visible structural concerns.

What a visual home inspection generally cannot establish is whether the installation was properly engineered, whether every component conforms to the original approved foundation design, whether all required permits received final approval, or whether a 433A was recorded. Those are documentation questions.

A manufactured home's legal status should normally be confirmed through sources such as the county recorder, HCD records, title company, lender, and applicable local building department.

Why Does a 433A Matter When Buying a Manufactured Home?

The issue frequently arises because of financing. A lender may require documentation establishing that a manufactured home is legally attached to the underlying real property before it will make a particular type of real-estate loan. That is why buyers often first hear about a “433A” from a lender, appraiser, real-estate agent, or title company rather than from a home inspector.

A lender may require a recorded 433A before financing a manufactured home as real estate. That does not mean every manufactured home in California is required to have one. Many manufactured homes remain legally titled as personal property.

For a buyer, the practical question is whether the home's current title and foundation status satisfy the requirements of the proposed loan and transaction.

Three Important Questions That Should Be Kept Separate

When evaluating a California manufactured home, it helps to ask three different questions:

1. Is the foundation and support system physically performing adequately? That is primarily an inspection and structural-condition question.
2. Was the manufactured home installed using an approved foundation system and were the appropriate permits and approvals obtained? That is primarily a permitting and engineering documentation question.
3. Has a 433A been recorded so that the manufactured home is legally a fixture or improvement to the underlying real estate? That is primarily a title and public-records question.

The answers to those questions may be related, but they are not interchangeable.

The Bottom Line

​Don’t be confused by the terminology. The key points are:

• A California manufactured home does not automatically require a 433A.
• The 433A, if filed with the county recorder, documents a specific legal process in which a manufactured home installed on an approved foundation system becomes a fixture or improvement to the underlying real property.
• It should not be assumed that “permanent foundation” means the manufactured home must be sitting on a traditional concrete perimeter foundation.
• You generally cannot determine whether a manufactured home has a 433A simply by looking underneath it.
• The physical foundation should be evaluated for its visible condition, while legal status, permitting, title, and financing requirements should be verified through the appropriate records and professionals.

Understanding these differences can eliminate a great deal of unnecessary confusion when buying or selling a manufactured home in California.

Why Do Insurance Companies Care About Electrical Panels?
Insurance companies evaluate a home based on the likelihood of a future claim. Electrical systems are important because electrical failures can result in fire, property damage, and personal injury. Some insurers may pay particular attention to:

• The manufacturer and design of the electrical panel
• The age of the panel
• Evidence of overheating or arcing
• Damaged or deteriorated bus connections
• Improper or incompatible circuit breakers
• Obsolete equipment for which replacement parts are difficult to obtain
• Electrical systems with a documented history of performance concerns

The underwriting rules vary considerably from one insurance company to another. One insurer may accept a particular panel without objection, another may require evaluation or replacement, and another may decline to insure the property altogether. For that reason, a home inspector cannot guarantee that a particular electrical panel will be acceptable to an insurance company.

Federal Pacific Stab-Lok Panels
Federal Pacific Electric, commonly abbreviated FPE, manufactured millions of electrical panels using the Stab-Lok breaker design. Federal Pacific Stab-Lok equipment has a well-documented history of concerns involving circuit breakers that may fail to trip properly during an overcurrent condition. Insurance companies may also consider these panels undesirable from an underwriting standpoint and may require replacement before issuing or renewing coverage.

The purpose of a circuit breaker is to interrupt electrical current when a circuit becomes overloaded or experiences certain fault conditions. A breaker that does not operate properly can allow wiring to overheat, increasing the potential for fire. Because of these concerns, many home inspectors recommend replacement of Federal Pacific Stab-Lok panels.

Zinsco and Sylvania-Zinsco Panels
Zinsco electrical panels are another older design that deserves particular attention. Zinsco was later acquired by GTE-Sylvania, and essentially the same equipment was sold under several names, including Zinsco, Sylvania, and Sylvania-Zinsco. These panels are associated with concerns involving the connection between the circuit breakers and the electrical bus bars inside the panel. Problems can include:

• Poor breaker-to-bus connections
• Overheating
• Arcing
• Damage to the bus bars
• Breakers becoming fused or otherwise damaged at the connection point
• Breakers that may not operate properly when needed

Because some of these problems may occur behind the breakers, the visible portions of a panel can sometimes appear relatively normal even when deterioration exists at the breaker-to-bus connection.
For this reason, Zinsco-type panels are generally considered a significant concern, and replacement is commonly recommended. They may also create insurance underwriting problems.

What About Challenger Panels?
Challenger panels require more careful identification. The name "Challenger" by itself does not necessarily mean that the panel has the same design or concerns as a Zinsco panel. During approximately the late 1970s and very early 1980s, some Challenger-branded equipment incorporated Zinsco-derived breaker and bus architecture. When that architecture is present, the panel should generally be viewed in the same manner as other Zinsco-family equipment because the concern is related to the underlying electrical design, not merely the brand name printed on the label.

Later Challenger panels used a different design. Those later panels should not automatically be considered equivalent to Zinsco or Federal Pacific equipment simply because they carry the Challenger name. However, older Challenger equipment can still present concerns related to age, breaker compatibility, obsolete components, or deterioration.

An insurance company may also have underwriting rules that apply broadly to Challenger-branded equipment regardless of the specific panel design. This illustrates an important distinction:
A panel can be acceptable from an inspection standpoint and still be unacceptable to a particular insurance company.

What About Pushmatic Panels?
Pushmatic panels are another type of older electrical equipment commonly encountered in homes built several decades ago. Pushmatic panels do not have the same widely documented failure history associated with Federal Pacific Stab-Lok or Zinsco equipment. However, most Pushmatic equipment is now quite old. Age-related concerns can include:

• Mechanical wear
• Breakers that are difficult to operate
• Limited availability of replacement components
• Previous modifications or mismatched breakers
• Deterioration caused by decades of service

An older Pushmatic panel should therefore be evaluated based on its design, condition, operation, and available components rather than simply being labeled either "safe" or "unsafe." Insurance companies may take a different approach and may have their own restrictions regarding Pushmatic equipment.

Edison-Base Fuse Panels and Type S Fuses
Older homes may still contain electrical panels or fuse boxes that use screw-in plug fuses rather than circuit breakers. The original Edison-base fuse uses the same general screw-in base configuration regardless of the fuse amperage. This creates an important limitation: a higher-amperage fuse can sometimes be installed in a circuit that was designed for a lower-amperage fuse.

​For example, a 30-amp Edison-base fuse could potentially be installed on wiring intended to be protected by a 15-amp fuse. This condition, sometimes referred to as overfusing, can allow the wiring to carry more current than it was designed to safely handle. Historically, homeowners also sometimes defeated fuse protection by installing oversized fuses or, in extreme cases, substituting conductive objects such as a copper penny where a fuse belonged.

Type S fuses were developed to reduce the possibility of overfusing. A Type S fuse uses a threaded adapter installed in the Edison-base fuse socket. Once the adapter is installed, only a Type S fuse within the appropriate amperage range can be inserted. For example, a 15-amp Type S adapter will not accept a 20-amp or 30-amp fuse. This provides an important safeguard against installing an oversized fuse.

When an older fuse panel is otherwise in good condition and is equipped with properly sized Type S fuse adapters, the presence of fuses alone does not necessarily mean that the electrical system is unsafe. However, older fuse equipment should still be evaluated for:

• Proper fuse sizing
• Type S adapters where appropriate
• Evidence of overheating or arcing
• Damaged fuse sockets
• Corrosion
• Improper modifications
• Double-tapped conductors
• Deteriorated wiring
• Missing covers or exposed energized components
• Limited electrical capacity for modern household loads

Some insurance companies may consider any fuse-based electrical service undesirable because of its age, limited capacity, or underwriting guidelines. Other insurers may accept an older fuse panel if it is in good condition, properly configured, and equipped with appropriate Type S fuse protection. As with older circuit breaker panels, the insurance company's underwriting decision is separate from the home inspector's evaluation of the electrical system.

An older fuse panel should therefore not automatically be described as defective solely because it uses fuses. The important questions are whether the equipment is properly configured, adequately sized, in serviceable condition, and acceptable to the buyer's insurance carrier.

Other Older Electrical Panels
There are many other older panel manufacturers and designs still in service. An older panel is not automatically defective merely because of its age. However, electrical equipment does not last indefinitely. During a home inspection, important conditions can include:

• Evidence of overheating
• Melted or discolored insulation
• Damaged bus bars
• Loose breakers
• Corrosion
• Water intrusion
• Improper wiring
• Double-tapped breakers where not permitted
• Oversized circuit breakers
• Incompatible replacement breakers
• Missing panel covers or filler plates
• Improper grounding or bonding
• Physical damage

The manufacturer is only one part of the evaluation. The actual condition and configuration of the equipment are equally important.

Circuit Breaker Compatibility Matters
Older electrical panels often accumulate replacement circuit breakers over many years.
A circuit breaker that physically fits into a panel is not necessarily approved for use with that panel. Breakers are designed and tested for specific panel and bus configurations. Installing an incompatible breaker can result in poor electrical connections, overheating, or other problems.
This is especially important with older Challenger, Bryant, Westinghouse, Cutler-Hammer, Murray, Crouse-Hinds, and similar equipment because several product lines changed ownership over the years. A qualified electrician can determine whether replacement breakers are properly listed or otherwise approved for use with a particular panel.

Insurance Concerns Are Different From Inspection Defects
This distinction is important for homebuyers. A home inspector may identify an electrical panel that is:

• Performing normally at the time of inspection
• Properly installed
• Free of visible overheating or damage
• Equipped with apparently compatible breakers

An insurance company may still decide that the panel does not meet its underwriting guidelines.
The opposite situation can also occur. An insurance company may be willing to insure a property even though the inspector identifies electrical defects that warrant repair or replacement. Insurance approval is not a substitute for an electrical safety evaluation, and an inspection does not guarantee insurance eligibility.

Buyers Should Address Insurance Questions Early
Homeowners insurance has become increasingly important to investigate early in many real estate transactions. If a home inspection identifies an older, obsolete, or potentially problematic electrical panel, the buyer should provide that information to their insurance agent as soon as practical.

Do not assume that insurance will automatically be available simply because the home has been insured previously. Insurance companies can change underwriting requirements, and the seller's current insurer may not be willing to issue a new policy to the buyer. Buyers should determine whether the electrical system is acceptable to their proposed insurer before applicable inspection, insurance, or other transaction contingencies expire. If the insurer requires replacement of an electrical panel, the buyer can then address the issue while there is still time to obtain estimates and discuss the matter with the appropriate parties.

The Bottom Line
Certain electrical panels deserve greater scrutiny because of their design, age, or documented performance history. Federal Pacific Stab-Lok and Zinsco-family panels are among the most significant examples. Some early Challenger panels incorporated Zinsco-derived architecture and should be evaluated accordingly. Later Challenger panels used a different design and should not automatically be treated as Zinsco equipment solely because of the Challenger name. Other older panels, including Pushmatic and later Challenger equipment, should be evaluated based on their condition, age, breaker compatibility, and other observed conditions. Insurance companies, however, may apply broader underwriting rules than a home inspector would use when evaluating the electrical system. For homebuyers, the practical lesson is simple:
​
When an inspection identifies an older or potentially problematic electrical panel, discuss it with both a qualified electrical contractor and your insurance agent before completing the purchase. A home inspector can help identify the equipment and visible electrical concerns. The electrician evaluates repair or replacement needs, and the insurance company determines whether the property meets its underwriting requirements. Those are three different roles, and understanding the distinction can prevent an unpleasant surprise late in the transaction.