Can you put solar panels on a manufactured home? The HUD roof load zones, state alteration permits and the ground-mount test

Find the roof load zone on your data plate before anything else

Every HUD-code home carries a data plate, which 24 CFR 3280.5 requires to be fixed near the main electrical panel or another readily accessible and visible spot. It lists the manufacturing plant, the serial number, the date of manufacture and, under paragraph (g), the roof load zone and wind load zone the home was designed for, with small copies of the federal zone maps. If the manufacturer built to a heavier load than the zone minimum, the plate states the actual design snow and wind loads instead. That one sticker is the starting input for any engineer, installer or state plan reviewer, and photographing it is the cheapest first step in the whole project.

The zone figures come from 24 CFR 3280.305(c)(3). Flat, curved and pitched roofs must resist a downward live load applied on the horizontal projection of the roof: 40 psf in the North zone, 30 psf in the Middle zone and 20 psf in the South zone. The counties in each zone are listed in the regulation itself, and the South zone is simply everything the other two lists leave out. The table below summarizes the lists as they read on eCFR on October 31, 2026.

Two things in that table catch owners out. The first is that most of the country, including mountain-adjacent counties in states not on the Middle list, sits in the 20 psf South zone. California, Washington, Oregon, Arizona, Nevada and Texas, which together hold a large share of rooftop solar interest, appear on neither the North nor the Middle list, so a standard home sold there is built to the lowest figure. The second is that the zone describes the home's design, not your address. A home built for the South zone and later moved into a snowier county is still a 20 psf home, which is one reason the data plate, not the map, is the input that matters.

The snow formula in the last row is what HUD says it would use if it set a stricter local requirement by rulemaking, not a load that automatically applies. Worked once to show the scale: a site with a 50 psf ground snow load would translate to a 30 psf roof snow load if exposed to wind (50 x 0.6) and 40 psf if sheltered (50 x 0.8). If your plate shows a figure above the zone minimum, the manufacturer designed for it, and the engineer starts from that number instead.

What 3 to 5 pounds per square foot means on a 20 psf roof

The Department of Energy's 2009 consumer guide, Own Your Power!, tells buyers to make sure the roof can hold a system it estimates at 3 to 5 pounds per square foot, depending on the technology and mounting method. That is a planning figure from 2009, and modern modules and rails vary, so the installer's datasheets give the real number for a specific array. It is still useful for scale, because it lets you put the array beside the HUD design loads.

The comparison has to be read carefully. The 20, 30 and 40 psf figures are live or snow loads: weight that comes and goes, such as snow, a roofer or ponding rain. Solar panels are dead load, permanent weight, and 24 CFR 3280.305(b)(1) says design dead loads are the actual dead load the structural assembly supports. A factory roof was designed for the dead load of its own sheathing and roofing plus the zone live load. An array adds dead load that was never in that calculation, and it sits there under every future snowfall. An engineer checks the combined dead and live load against the truss and connection capacity; the percentages below only show how large the addition is relative to the load the roof was rated for.

The pattern runs opposite to intuition. The homes in the mildest climates, built to 20 psf, see the largest relative addition, because their roofs were built lightest. A heavy array on a South-zone single-section home adds weight equal to a quarter of what the roof was designed to carry as live load. Whether that is acceptable depends on how much reserve the manufacturer's truss design holds, which only the engineering can show.

Concentration matters as much as the total. Rails transfer the array's weight to the roof through a limited number of attachment points, and each one bears on a truss or on sheathing between trusses. An array spread over 500 square feet at 4 psf weighs about 2,000 pounds (500 x 4), and that weight arrives at the roof through the feet, not evenly across the surface. Where the attachments land relative to the trusses is therefore part of the structural question, not an installation detail.

For contrast only: site-built houses often go through an over-the-counter screen. The City of Yakima, Washington, for example, lets contractors use an expedited permit for one- and two-family dwellings when the array's total dead load is no more than 4 psf and no attachment point exceeds 50 pounds, citing the International Residential Code. That screen is written for site-built dwellings under the IRC and has no standing for a HUD-code home, which in Washington goes to the state, not the city. The site-built path is covered in the guide to whether a site-built roof can support solar.

The 30 psf misreading

Reading the data plate's roof load as spare capacity. A home marked 30 psf has not got 30 psf to give away: that figure is the live or snow load the roof was designed to carry on top of its own weight, and snow still arrives after the panels are installed. The array's 3 to 5 psf is added on top, permanently, and the question an engineer answers is whether dead plus live load still fits the truss design. An installer who points at the zone number and says there is plenty of room has skipped the calculation the state permit asks for.

Wind zones and the 3-foot strips along the roof edges

Weight pushes down; wind pulls up, and on a light roof the upward pull is often the harder design problem. Under 24 CFR 3280.305(c)(1)(i), a standard Wind Zone I home is designed for a horizontal wind load of at least 15 psf and a net roof uplift of at least 9 psf, and that uplift may not be reduced by the roof's own dead weight in the engineering. Eaves and cornices in Zone I are designed for 2.5 times the uplift figure, which works out to 22.5 psf (9 x 2.5). Homes for Wind Zones II and III, the hurricane-coast counties listed in the regulation plus all of Hawaii, coastal Alaska and the U.S. territories, must be designed by a professional engineer or architect to 100 mph or 110 mph design wind speeds, or to the pressure table reproduced in part below.

The table shows where the roof itself is most exposed: within 3 feet of the gable ends, the suction the coverings are designed for is 73 psf in Zone II against 39 psf in the general field, nearly double. Strips along the ridge and eaves sit in between. An array mounted on rails acts on the roof as a lever whenever wind gets under the modules, and the attachments transfer that pull into fastenings that were designed for these figures without any array in the picture. An engineer reviewing a Zone II or III home will want the layout drawn against those 3-foot strips, and keeping the array in the general field is the obvious starting position.

Wind zone also shows on the data plate, along with a printed warning that a Zone II or III home has not been designed for ocean exposure within 1,500 feet of the coastline unless the home and its anchoring were designed for the higher Exposure D loads. A home inside that band carries its own structural questions before any panel goes up. For homes in Florida, the Gulf Coast and the Carolinas, the wind analysis is often the line that decides between roof and ground.

Why the federal code says nothing about solar

A search of the full text of 24 CFR Part 3280, the Manufactured Home Construction and Safety Standards, on October 31, 2026 returned no use of the words solar or photovoltaic. The standards govern how the factory builds the home: structure, fire safety, plumbing, heating and the electrical system, which 24 CFR 3280.801 builds to the 2014 edition of the National Electrical Code as incorporated by reference, including Part II of Article 550. They do not describe how to add an array afterward, and no HUD rule approves or forbids one.

The enforcement rules in 24 CFR Part 3282 explain where the gap falls. Part 3282 defines an alteration as replacing, adding, modifying or removing equipment after the manufacturer sells the home to a retailer or distributor but before the retailer sells it to a purchaser, where the change may affect construction, fire safety or the electrical system. Section 3282.254 then says a retailer or distributor who alters a home so that it no longer conforms may not sell it until the problem is corrected. Those duties attach to the sales chain. Once the home reaches its first purchaser, Part 3282 deals with owners mainly through complaint and defect procedures, and it does not set out a federal permit for an owner who later adds equipment to the roof.

States fill that space through their own manufactured housing programs, and the two programs read for this guide take the same position: a rooftop array on a manufactured home is a state-permitted alteration, reviewed by the state agency that regulates factory-built housing, not by the city building department that permits arrays on site-built houses. Section 3282.11 bars states from setting their own construction standards that differ from the federal ones for aspects the federal code covers; the two state programs below nonetheless require a permit for a solar alteration after sale, and an owner in those states follows them.

One related federal rule is worth knowing because installers sometimes cite it loosely. The data plate statement under 24 CFR 3280.5(d) says whether the home IS or IS NOT designed to carry the additional loads of an attached accessory building or structure, such as a carport or porch tied to the home. That statement is about accessory structures, not about solar, so a home marked IS does not thereby have spare roof capacity for panels. It does tell an engineer that the manufacturer's design anticipated some added load, and the design loads it lists are useful inputs.

California and Washington: the state permit routes, dated

The two official documents below are the clearest statements found of what a state expects. Other states run their own manufactured housing offices, and some delegate to local inspectors, so the table is a pattern to check against, not a national rule. The state permit office is usually the same office that handles manufactured home installation permits, and a call there before signing anything settles which route applies.

California's advisory is short and blunt. Its headline warns homeowners of potential negative impacts from attaching panels to manufactured home roofs, and its points are that a permit from HCD, the state housing department, is required for any solar system on a manufactured home, that the permit protects the owner from damage caused by installers, that damage from poor installation on these roofs is not visible because the roofs are not accessible, and that the solar company should hold a Contractors State License Board license and have obtained the HCD permit before the owner signs. A California installer who pulls a city or county permit for a manufactured home, or none at all, is using the wrong route.

Washington's publication is a step-by-step form. Labor and Industries, which describes itself as the state's building department for factory-assembled structures since 1968, requires an alteration permit for added electrical circuits and, when the panels go on the roof, a second permit for structural inspection. The plans must show where the panels and equipment go, how they attach and are supported, how the roof can support the added weight, a complete wiring diagram, the connection to the home's existing electrical system, electrical calculations of voltage and current, and manufacturers' product information. Structural plans must carry the stamp of a Washington professional engineer or architect, plan review carries a fee added to the permit, and review usually takes two to three weeks. The electrical work must be done by a licensed electrical contractor, the owner is responsible for calling for the electrical and structural inspections, and the inspector typically makes contact in about ten days. The form also warns that work without a permit and inspection can affect the home's safety, its financing and its insurance.

Read together, the two documents describe the job an owner is buying. It is not a standard residential install with a different roof surface; it is an engineered structural alteration with a state plan review, and the timeline and fees for that review belong on the quote. The general cost of permits for site-built systems, and how to read them on a quote, is set out in the solar permit cost guide; on a manufactured home, ask for the state alteration permit and the engineering as their own lines.

Mobile homes built before June 15, 1976, and modular homes

The HUD code applies to manufactured homes that entered the first stage of production on or after June 15, 1976, under 24 CFR 3282.8(a), plus a small number of earlier homes that received labels under the transition rules. A home built before that date is, in the regulation's terms, outside the federal standards. It has no HUD data plate, no certified roof load zone and no federal design record. Some were built to industry standards of the day, and some were not.

For solar, that changes the engineer's job from checking a known design to establishing an unknown one. With no rated load to start from, the engineer has to inspect the framing, identify the members and their spacing, and calculate capacity from scratch, often on a roof that has been overlaid or patched over five decades. Many such roofs will not carry an array without reinforcement, and the cost of reinforcing a structure that old can exceed the cost of a separate ground structure. For a pre-1976 home, a ground mount or a community solar subscription is usually the first option to price, not the fallback.

Modular homes are the opposite case. Under 24 CFR 3282.12, a factory-built structure designed only for a permanent site-built foundation can be excluded from the HUD code when its manufacturer certifies it as modular, and those homes are built to the state or local building code that governs site-built houses. A modular home's roof is permitted for solar the way a site-built roof is, by the local building department, and the HUD load zones above do not apply. The quickest way to tell the difference is the label. Under 24 CFR 3280.11, a HUD-code home carries a separate certification label of about 2 by 4 inches, etched on aluminum and riveted or screwed to the outside of each transportable section, normally at the taillight end about a foot up from the floor, in addition to the data plate inside. A home with neither is either pre-1976 or not a HUD-code home, and the answer changes accordingly.

The size definition in 24 CFR 3280.2 rarely settles the question on its own, but it explains why so many homes are covered: a manufactured home is any structure built on a permanent chassis, transportable in one or more sections, that is 8 body feet wide or 40 body feet long in traveling mode, or 320 square feet once set up. Nearly every single-section and multi-section home in a community or on private land meets it.

Roof or ground, priced against the benchmark

Once the structural question is clear, the choice becomes a cost comparison between two extras. The roof route costs the array plus engineering, state plan review and any reinforcement the engineer requires. The ground route costs the array plus foundations, racking built to stand free, and a trench to the home's electrical service, and it needs yard. Neither extra has a national published figure, so the useful step is to ask for both as separate lines and compare them directly. The general trade between mounts is laid out in the ground mount versus roof mount guide; on a manufactured home the structural line tilts the comparison further than it does on a site-built house.

The common baseline is the Department of Energy's Q1 2025 residential cost benchmark: a modeled market price of $2.95 per watt DC for an 8 kW PV-only system, in 2024 dollars, which puts 8 kW at $23,600. The model prices an 8 kW national reference system, and applying it to a smaller array is a rough approximation, since fixed costs weigh more per watt on small systems. No federal residential solar tax credit appears in any figure here; it ended for systems placed in service after 2025. How to divide a quote into per-watt terms is shown in the cost per watt guide.

Space is the other input. The same 2009 DOE guide plans on about 100 square feet of unshaded south-facing roof or yard per kilowatt, and up to 175 square feet per kilowatt for thin-film modules. A manufactured home with a single ridge running its length offers one usable slope, minus the edge strips that wind design and fire access may keep clear, so the roof often caps system size before the budget does. How that cap translates into a system size is the subject of the panel sizing guide.

Every number except the benchmark line is an illustration input, chosen to show how the decision turns, and real quotes will differ. The arithmetic: 5,000 x $2.95 = $14,750; $14,750 + $1,200 = $15,950, or $18,450 with $2,500 of reinforcement; $15,950 / 5,000 = $3.19 and $18,450 / 5,000 = $3.69 per watt. On the ground, 5,000 x $0.60 = $3,000, and $17,750 / 5,000 = $3.55 per watt. The decision rule falls out of the structure of the table: the roof wins when the engineer finds capacity without reinforcement, the ground wins when reinforcement is needed and the yard exists, and when neither works, neither array is the answer.

A 2004 single-section home, worked from the data plate

A single-section home in a South-zone county, built in 2004, owned with its land. The data plate shows Roof Load Zone South, Wind Zone I, and the IS NOT statement for attached accessory structures. The owner wants a 5 kW array. The home's dimensions here are invented for the illustration: 16 feet wide and 72 feet long, with a ridge down the middle, so the south-facing slope covers about 8 x 72 = 576 square feet in plan.

Space comes first. At the DOE planning rate of 100 square feet per kW, 5 kW needs about 500 square feet. Keeping a 3-foot strip clear at each gable end (an assumption for this illustration, borrowed from the edge strips in the Zone II and III table) leaves 8 x 66 = 528 square feet, so the array just fits if nothing else is on that slope, such as plumbing vents or a swamp cooler. Weight comes next: at 4 psf, the middle of the DOE range, 500 square feet of array weighs about 2,000 pounds, a permanent addition on a roof whose rated live load is 20 psf, against which 4 psf is a fifth.

The owner's state requires an alteration permit with engineered plans. The engineer's letter, in this invented case, finds the trusses adequate if attachments land on every truss with a stated spacing, so the reinforcement line is zero. The roof route at the benchmark comparison line is $14,750 plus a $1,200 engineering and review allowance, $15,950 in all, or $3.19 per watt. The ground route on the same illustration inputs is $17,750, or $3.55 per watt, and needs 500 square feet of unshaded yard. Here the roof wins by $1,800 ($17,750 minus $15,950). Had the engineer called for $2,500 of reinforcement, the roof would reach $18,450 and the ground would win by $700 ($18,450 minus $17,750), provided the yard is there.

Land-lease communities: the lot may not be yours to build on

A manufactured home is owned either with the land under it or, in a land-lease community, as a home on a rented lot. The second case changes the ground-mount column, and sometimes the roof column too. A lease or community rules may restrict structures on the lot, require written approval for exterior changes, or say nothing at all. State law on community rules varies widely, and no general statement holds across states, so the lease itself is the document to read.

In practice the questions to put in writing to the community manager are short: whether a roof-mounted array needs approval, whether a ground array is allowed on the leased lot and where, who owns and removes the equipment if the home is sold or moved, and whether the community has its own electrical distribution or each home has a utility meter. That last question matters more than it sounds. If the community master-meters electricity and resells it, the home may not have the direct utility account that interconnection and net metering assume, and the utility, not the installer, decides what can connect.

Owners who face a no from the community, or a lot too small or shaded for a ground array, still have options with no structure involved. A community solar subscription carries no equipment at all, and where a state program exists, the comparison of community solar with rooftop ownership runs the numbers over 20 years. Where an association rather than a landlord controls approvals, the access laws in the HOA solar rules guide may apply, depending on how the community is organized.

The electrical side: service size and who may wire it

A manufactured home's electrical system is built to the National Electrical Code as incorporated into the HUD standards, and 24 CFR 3280.801 sets the system as one intended for a 120/240 volt, 3-wire supply with a grounded neutral, with every device listed or labeled by a recognized testing agency. Nothing in that section addresses solar. A rooftop or ground array connects through the home's panel or service equipment under whatever edition of the electrical code the state permit office enforces for alterations, and that office decides what the connection must look like.

Panel capacity is a frequent second hurdle. Older homes in particular may have a modest service, and an inverter's backfeed has to fit the panel's busbar and main breaker rules. When it does not, the fix is a panel upgrade or a supply-side connection, each with its own price and permit. The options and their costs for site-built homes are explained in the main panel upgrade guide; on a manufactured home, ask the installer to confirm the service rating and panel model in writing, and to show the connection method on the plan the state reviews.

Washington's form says plainly that the electrical installation must be done by a licensed electrical contractor. California's advisory points owners to the Contractors State License Board. In both states the person wiring the system is a licensed trade, not a general handyman, and the license check guide shows how to verify a contractor in a state's official lookup before work begins.

Before you sign: the papers that make a roof mount safe

Most problems with solar on manufactured homes start with a contract signed before the structural question was asked. A door-to-door pitch that never mentions the data plate, the state alteration permit or an engineer is a warning sign in itself, and the general pattern of those pitches is described in the door-to-door solar guide. The list below is what a complete roof-mount proposal for a HUD-code home should already contain.

Roof condition still matters on top of structure. Many manufactured homes have metal or low-slope roofs, and attachment methods differ by roofing type, as the metal roof mounting notes explain. An array that has to come off for a roof replacement adds a removal and reinstallation bill, so a roof near the end of its life should be dealt with first, as the guide to replacing a roof before solar sets out. Insurers ask about permitted alterations too, and the solar insurance guide covers what to tell the policy.

What a complete manufactured home solar proposal contains

• A photo of the data plate showing roof load zone, wind zone and date of manufacture, attached to the proposal.
• The state agency that permits alterations to manufactured homes at your address, named in the contract (HCD in California, Labor and Industries in Washington), with the permit fee and plan-review time quoted.
• An engineer's or architect's letter or stamped plan showing the roof can carry the array, or a written statement of why the installer proposes a ground mount instead.
• An attachment layout drawn against the trusses, keeping clear of the 3-foot edge strips where the home's wind design is strictest.
• The array's dead load in pounds per square foot and the weight per attachment, from the module and racking datasheets.
• The service rating, panel model and connection method, with the licensed electrical contractor named.
• For land-lease homes, the community's written approval and its rules on removal if the home is sold or moved.
• A separate price for the ground-mount alternative, so the roof route is compared rather than assumed.