Mobile home installation requirements are not one document: they are a federal baseline plus your state’s amendments. This is the reference page we work from. It is written for homeowners, inspectors, park managers and buyers who want the actual requirements rather than a marketing summary. It covers HUD’s installation standards, wind zones and anchoring loads, installer licensing, HUD tags, and how transport permits fit alongside installation permits.
Table of Contents
Everything below is drawn from HUD’s installation standards, the state amendments that modify them, and the inspection practice we meet on site. Mobile home installation requirements are technical by nature, so this page is organised the way an inspector works: foundation, structure, anchoring, envelope, connections.
The federal baseline: HUD 24 CFR 3285
Manufactured homes are installed under HUD’s Manufactured Home Installation Program, codified at 24 CFR Part 3285. The standards address site preparation, foundation and support systems, anchoring against wind, ductwork, plumbing and electrical connections, and the required installation instructions supplied by the manufacturer.
Key structural requirements that come up on almost every job:
- Support and blocking must follow the manufacturer’s installation instructions for that specific home, including pier spacing and the capacity of stabilizing devices.
- Anchoring must resist wind loads for the design wind zone, using an anchor assembly system per Subpart E or an engineered foundation per 3285.301.
- Any home built after 20 October 2008 requires tie-downs or an engineered foundation system.
- Installation instructions must be provided with the home and must include the dimensional parameters needed to verify tie placement.
Tie-downs: the numbers inspectors check
| Requirement | Value | Source |
|---|---|---|
| Anchor working load | At least 3,150 lb | 24 CFR 3280.307 / 3285 anchoring provisions |
| Overload capacity | 4,725 lb (50% overload) without failure | Same |
| Diagonal tie angle | 30–60 degrees to the ground | 3285.402 and manufacturer instructions |
| Vertical ties | Required at each diagonal location in Wind Zones II and III | 3280.307 |
| End spacing | Not more than 2 ft open-end spacing on each end | 3280.307 |
| Strap protection | Required at sharp corners and where straps contact siding | 3280.307 |
Wind zones
HUD design wind zones determine the structural and anchoring requirements: Zone I up to 70 mph, Zone II up to 100 mph and Zone III up to 110 mph. The zone is set by the installation location. A home designed for a lower zone and installed in a higher one generally needs upgrading, and insurers increasingly ask for evidence.
Anchoring detail by zone is covered on the tie-down page.
Installer licensing and certification
HUD’s programme relies on states to administer installation, and states vary widely:
- Some license individual installers and require continuing education.
- Some require a certification filing (HUD 309 in HUD-administered states) confirming the installation meets the standards.
- Some require an installer’s seal affixed to the home.
- Some delegate to local building departments with their own inspection regimes.
Practical consequence: the licence is part of the permit, and an unlicensed install fails inspection regardless of workmanship. We confirm the requirement for the destination address before quoting.
HUD label, data plate and title
The HUD label is the exterior certification tag; the data plate inside the home lists the design information including wind zone, thermal zone and the home’s serial numbers. Both matter for financing, insurance, resale and, in some states, the transport permit. A missing label is not automatically fatal, but it needs to be resolved before closing — not after the truck is booked.
Transport permits versus installation permits
| Transport permit | Installation permit | |
|---|---|---|
| Issued by | State DOT (and sometimes city/county) | Local building or code authority, or state agency |
| Governs | Moving an oversize load on public roads | Setting, blocking, anchoring and connections on site |
| Typical lead time | Minutes to 5 business days | 3–15 business days |
| Common failure point | Height or width mis-measured; missing transit state | Unlicensed installer; anchoring not matching wind zone |
Both are handled in our relocation sequence.
Site preparation requirements that get skipped
- Drainage. Surface water must move away from the home; standing water under a home destroys piers and vapour barriers.
- Pad and footing. Piers need proper footings, not bare soil, and the pad has to be compacted.
- Vapour barrier and ventilation. The belly must be protected and the skirting must vent, or condensation rots the rim joist.
- Utility trenching. Trenches need correct depth, bedding and protection, and inspection where required.
Our setup page covers the sequence; our inspection service catches the failures before the code officer does.
Mobile home installation requirements by category
Mobile home installation requirements fall into five groups, and an inspector will move through them in roughly this order.
| Category | Core requirement | Common failure |
|---|---|---|
| Site and foundation | Graded, drained, proper footings, piers per instructions | Piers on bare soil; water running under the home |
| Structural set | Sections aligned, fastened and sealed at the marriage line | Floor flush, roof misaligned; seal skipped |
| Anchoring | Hardware to 3,150 lb / 4,725 lb, angles 30–60 degrees, vertical ties by zone | Wrong angle; missing vertical ties |
| Envelope | Vapour barrier intact, skirting vented | Torn belly; sealed skirting with no vents |
| Connections | Water, sewer, electrical and gas to code, by licensed trades | Unbonded panel; unsupported pipe |
Those mobile home installation requirements are the same whether the home is new, relocated or re-sold. What changes is who certifies them.
Mobile home installation requirements and state amendments
States adopt the federal standards with amendments, and some add their own installation programme. The amendments typically tighten anchoring for local wind exposure, add installer licensing and certification, or set additional inspection steps. A home installed to the letter of the federal standard can still fail a state requirement.
Practical approach: confirm the destination state’s adoption and any licensing rule before the permit is filed. Our permit page covers the transport side, and the setup page covers the installation sequence.
Who enforces mobile home installation requirements
Enforcement runs through the local code office in most jurisdictions, with the state agency overseeing where a programme exists. The installer certifies, the code officer inspects, and the homeowner holds the record. Where a lender or insurer is involved, they may ask for the same documents a second time, which is why keeping the file matters.
If a home was installed without a permit, the correction path is usually a retroactive permit and inspection, not a demolition. Start with the code office and be straightforward about what was done. Our inspection service can document the existing condition first.
Use this page as a reference, not as a substitute for the authority having jurisdiction. Mobile home installation requirements are amended at state and local level, and the version that applies is the one in force at the installation address on the day of inspection. If you are preparing for an inspection, our inspection service checks the same items in the same order — and finds the failures while they are still inexpensive to fix.
Quick answers on mobile home installation requirements
- Federal or state? Both — mobile home installation requirements start with HUD 3285 and are amended by the state that administers installation.
- Who certifies? A licensed installer where the state requires one, and mobile home installation requirements decide whether that filing is a HUD 309 or a state form.
- Which wind zone? The zone at the installation address, which is why mobile home installation requirements and home design must match.
- What if it was never permitted? A retroactive permit and inspection is the usual path, and documenting the condition first is the practical start.
- Does anchoring expire? No, but hardware corrodes and mobile home installation requirements assume the assembly still meets its rated load.
- Who keeps the record? The homeowner, and mobile home installation requirements at resale depend on that file existing.
- Where do I start? With the code office for the destination address, because local mobile home installation requirements override the general rule.
Frequently asked questions
Is HUD 3285 the same in every state?
No. States adopt the federal standards with amendments, and some operate their own installation programmes with additional licensing, filing or inspection requirements. The destination state’s rules govern.
Who can legally install a manufactured home?
In states with installer licensing, a licensed installer. Elsewhere, the requirement may fall to a licensed contractor or be administered through the local code office. Confirm before work starts.
What is a HUD 309 form?
An installation certification form used in HUD-administered states, submitted by the licensed installer to confirm the installation meets the standards.
Does anchoring affect insurance?
Yes, particularly in high-wind states. Carriers may ask for evidence of compliant anchoring, and a mismatch between the home’s design zone and the installation zone creates both a code and an underwriting problem.
What the federal standard actually covers, part by part
The installation standard is long, but it is not mysterious. It is organised by the thing being installed, and each part answers a question a homeowner eventually asks. Reading it this way makes the document usable instead of intimidating.
| Part of the standard | The question it answers | Where it bites on a real job |
|---|---|---|
| Site preparation | What has to be true about the ground before a home arrives? | Drainage, grading, soil bearing and access |
| Foundations and support | What holds the home up, and how far apart? | Pier spacing, footing size, frost depth |
| Anchoring | What stops the home moving in wind or seismic events? | Anchor type, pattern and tension by zone |
| Structural assembly | How do sections join into one building? | Marriage line, gaskets, fastening schedule |
| Exterior and thermal envelope | How is the underside closed and insulated? | Vapour barrier, skirting, ventilation |
| Utilities | Who may connect what, and to what standard? | Crossover, electrical connection, gas piping |
| Post-installation | What proves the job was done to standard? | Certification, inspection, records |
Every county inspection is essentially a walk through that table. If you know which part a query belongs to, you can find the requirement, and you can tell whether the answer you were given is correct.
Design zone versus installation zone
These two are constantly confused, and the confusion causes real problems at resale and at insurance renewal.
- Design zone is assigned where the home was built. It is recorded on the data plate and it tells you what the structure was engineered for.
- Installation zone is assigned where the home is being set. It is decided by the county or the state’s wind map.
A home designed for a lower wind zone can sometimes be installed in a higher one with an engineered foundation and a heavier anchoring pattern; sometimes it cannot be installed there at all. That determination is made by a design professional or the manufacturer, not by the installer’s judgement, and it should be documented in writing before any pier is placed. When the two zones match, the standard installation details apply and the job is straightforward.
What an inspector looks for, in the order they look
Access and exposure
Can the underside be inspected? Skirting closed up before inspection is a stop-work item, not a formality.
Support
Pier count against the plan, pier condition, shimming, caps and footing bearing on undisturbed or compacted ground.
Level
Frame measured against tolerance, longitudinally and transversely, with readings rather than a visual check.
Anchoring
Anchor type and spacing against the zone requirement, tension, and the condition of the straps at every contact point.
Marriage line and envelope
Join condition, gaskets, fasteners, and the vapour barrier and skirting with their ventilation intact.
Utilities
Connections made by the licensed trade, with the permits that go with them.
Records
The certification, the permit set and the installer’s licence details, signed and dated.
The five findings that fail most inspections: insufficient pier support under a heavy addition, an anchor pattern that does not match the zone, a level reading outside tolerance at the marriage line, a vapour barrier with gaps at the piers, and skirting installed with no ventilation. None of them are exotic. All of them are visible in twenty minutes if someone looks.
How state adoption changes the requirement
The federal standard is a floor, not a ceiling. States adopt it, amend it, and enforce it through different mechanisms, which produces three practical patterns.
| Pattern | How it works | What you should ask |
|---|---|---|
| State-administered | The state runs the installation programme and licenses installers directly | Who holds the licence, and what certification is filed |
| Locally enforced | The county or city inspects against the adopted state code | Which office inspects, and what they require at sign-off |
| Third-party certified | A private inspection agency certifies on the jurisdiction’s behalf | Which agency, and whether their report satisfies your lender |
This is why a company that operates in twelve states cannot describe its process in one paragraph. The work is the same; the paperwork is not.
Verifying an installer’s credentials without taking their word for it
- Ask for the licence number, then check it against the state’s public register. A number that cannot be verified is not a credential.
- Ask which standard the certification references — the state’s adopted version, not “HUD standards” in general.
- Ask who signs the certification and whether that person will be on site. On many jobs the signature is the accountability.
- Ask for the certificate of insurance and read the limits and the effective dates, not just the company name.
- Ask what happens if the inspection fails — who pays for the re-inspection and the correction.
The full federal text sits in 24 CFR Part 3285, and the state’s own adopted version is what an inspector will actually apply. Where the two differ, the stricter one governs in practice. Our inspection guide covers what the sign-off involves on the day, and the anchoring page explains how the zone translates into a pattern.
Records: how long to keep them, and why
Keep the installation file for as long as you own the home, and hand it to the buyer when you sell. It is the only evidence that the home was set to the standard that applied at the time, and it is the first thing a surveyor, an insurer or a buyer’s attorney will ask for. Photographs, level readings, the anchor pattern, the permit set and the signed certification are the five items that matter most. A missing file does not mean the installation was defective — but it means you cannot show that it was not, and that is a discount at resale.
The terms, in plain language
Code language is precise and unfriendly. These are the words that cause the most confusion in conversation with a homeowner.
| Term | What it means on your job |
|---|---|
| Data plate | The paper or metal label inside the home listing the design zone, wind and thermal ratings, and the home’s identity |
| HUD label | The metal certification tag on the exterior; its absence affects insurance, resale and sometimes permitting |
| Pier and footing | The support under the frame and the element that spreads that load into the ground; both have size and spacing requirements |
| Tie-down | The strap or cable that connects the frame to a ground anchor, specified by pattern and tension |
| Marriage line | The join between two sections of a multi-section home, and the most common place for water to get in |
| Vapour barrier | The ground cover under the home that stops moisture rising into the structure |
| Certification | The signed confirmation that the installation meets the adopted standard |
Checking your own state’s rules in ten minutes
- Find the adopting agency. Search for your state plus “manufactured home installation program”. Most states publish the adopted code version and the licensing requirement on one page.
- Call the county building department with the parcel address and ask two questions: what installation standard applies, and who inspects.
- Ask for the wind zone for that parcel if it is in a coastal or high-wind county. It determines the anchor pattern and sometimes whether the home may be sited.
- Read the federal baseline in 24 CFR Part 3285 so you can recognise an answer that does not match it.
Ten minutes of that is worth more than an hour of forum reading, because the county’s answer is the one that will be applied to your home. If the answer surprises you, our inspection guide explains what happens on the day and how corrections are handled.
Mobile home installation requirements: the questions inspectors actually ask
Mobile home installation requirements are set federally, adopted by the state and enforced locally, which is why the answer to a simple question can depend on the county. These are the seven that come up most.
Which mobile home installation requirements apply to my address?
The state’s adopted version of the federal standard, plus any local amendment. The building department is the authority; ask them before the home arrives.
Do mobile home installation requirements change with the wind zone?
Yes. Higher zones require heavier anchoring and sometimes an engineered foundation, and the home’s design zone has to be compatible.
Are mobile home installation requirements different for a used home?
The requirements are the same. What changes is the condition of the frame and the roof, which affects whether the home can meet them.
Who certifies that mobile home installation requirements are met?
A licensed installer in some states, the local inspector in others, and a third-party agency in a few. The certification has to name the standard applied.
What happens if mobile home installation requirements are not met?
The inspection fails, the item is corrected and the inspection is repeated. Occupying the home first makes the correction your responsibility.
Do mobile home installation requirements cover utilities?
They cover the connections within the installation scope. Electrical and gas work belongs to licensed trades, with their own permits and inspections.
Where can I read mobile home installation requirements myself?
The federal text is 24 CFR Part 3285, and the state publishes its adopted version. Reading both tells you which question to ask your county.
Mobile home installation requirements in short
- Mobile home installation requirements are federal, adopted by state and enforced locally.
- Wind zone changes mobile home installation requirements for anchoring.
- Mobile home installation requirements apply equally to new and used homes.
- Certification confirms mobile home installation requirements were met.
- Mobile home installation requirements cover the envelope, not the roof covering.
- Local amendments sit on top of mobile home installation requirements.
- Utilities fall partly outside mobile home installation requirements.
- The county is the authority on mobile home installation requirements for your parcel.
- Mobile home installation requirements are published in 24 CFR Part 3285.