Cutaway of manufactured home.

Hire smart. L&I can help.

Learn what you can do to get the job done right — the first time.

Wildfire recovery

Cutaway of manufactured home.

Choose your project:

Addition

Building a garage, shop or room addition?

An L&I alteration permit is required. L&I electrical permits may be required for any electrical wiring extended into the addition. Be sure all electrical work is done by a licensed electrical contractor.

In most cases, plan approval by L&I is required before construction.

Check out the "Adding an Addition" fact sheet for more information.

Appliances

Replacing appliances?

You may need an L&I alteration permit. No alteration permit is required when replacing old appliances and not changing plumbing or electrical lines.

Work with a registered contractor when making significant changes. If the installation is being subcontracted, get the name of that contractor too.

Concrete

Need concrete work?

No L&I alteration permit is required.

Beware of door-to-door paving companies offering great deals and on-the-spot service because they have "leftover materials" or are already "in the neighborhood." Reputable contractors expect you will want an upfront bid, and won’t expect you to make a snap decision.

Doors

Wall openings and framing for doors, additions, or windows?

An L&I alteration permit is required for new and changed exterior openings. However, no alteration permit is required for replacing windows and doors fitting the old/existing openings.

In some cases, plan approval from L&I is required before work begins.

See our publication, What You Should Know: Adding or Changing the Openings in the Exterior or Centerline Walls of Your Manufactured or Mobile Home (F622-096-000), for more information.

Remember: Verify the contractor has posted a minimum bond and purchased liability insurance — and whether the company’s registration is up to date with L&I.

Electrical (inside)

Electrical panels and wiring

An L&I alteration permit is required for most types of electrical work.

For safety’s sake, hire an experienced, registered electrical contractor who is licensed to do the work. You could jeopardize insurance coverage if there’s a fire after non-permitted or non-inspected electrical work is done. A complete list of work requiring permits is in our publication, Your Manufactured/Mobile Home (F622-049-000).

Electrical (outside)

Electrical hookup and outside wiring

An L&I alteration permit is required if circuit wiring is extended from the home into a garage. Many types of work require a permit. A complete list is in our publication, Your Manufactured/Mobile Home (F622-049-000).

Electrical work permits may be required for hooking up a manufactured home to power or to install outside electrical wiring that does not extend from the manufactured home. Also, check with the city or county for any additional requirements.

Be sure all electrical work is done by a licensed electrical contractor.

Foundation

Set up, foundation and site permits

No L&I alteration permit is required for repairs. You will need permits and inspections from your local jurisdiction.

An L&I-certified installer, who can also be a contractor, is necessary to set up a manufactured home, including work on the foundation and skirting around the crawl space.

Furnace/AC

Installing a furnace, heat pump or A/C system?

An L&I alteration permit is required for most types of heating and cooling jobs, furnace installation, or extending gas piping. A complete list of work requiring permits is in our publication, Your Manufactured/Mobile Home (F622-049-000).

Hire registered contractors who are certified to do the work. Check with your utility about any rebates that may be available.

Gutters

Drainage problems?

No L&I alteration permit required.

Downspouts and gutters a leaky mess? Water pooling in your backyard? Hire a registered contractor to fix the problem. An amateur job could leave you with a soaked foundation.

Siding/Paint

Replacing the house siding or painting?

An L&I alteration permit is required to replace siding. No alteration permit is required for painting.

Be sure to hire a registered contractor who provides you with a detailed, written bid that includes everything, including scraping, caulking, priming, at least two coats or paint, and cleanup. Some contractors will leave out important items to make the bid appear unbelievably low.

See our fact sheet, What You Should Know: Replacing the Siding on Your Manufactured or Mobile Home (F622-093-000), for more information.

Plumbing

Plumbing fixtures and piping

An L&I alteration permit is required whenever you add, replace, or alter the water or drain piping in your manufactured home. A permit is also required for replacing bathtubs and showers. A permit is not required to replace faucets, sinks, toilets and similar devices, when there are no changes to the existing water or drain lines.

A permit and plan approval from L&I are required to install a residential fire sprinkler system.

In all cases, make sure you hire a registered contractor and that a certified plumber does the actual work. Your homeowner's policy might not cover any damage caused by an uncertified plumber.

Pond/Sprinklers

Installing lawn sprinklers or a pond?

No L&I alteration permit is required.

Adding a deck, awning or porch?

An L&I alteration permit may be required. An electrical permit is required for any electrical wiring included.

You may also need permits from your local jurisdiction. In some cases, plan approval by L&I is required before beginning construction.

Be sure you hire a registered contractor to do this work. Electrical work should be done by a registered electrical contractor.

See our publication, Adding a Deck, Awning or Porch (F622-095-000), for more information.

Rafters/Trusses

Repairing trusses and rafters?

An L&I alteration permit is required to repair or replace roof trusses, rafters and beams.

In most cases, plan approval by L&I is required before work begins.

See our publication, Repairing Damaged Trusses or Rafters (F622-094-000), for more information.

Remodel

Planning an interior remodel?

An L&I alteration permit is required for some interior remodeling. See our publication, Your Manufactured/Mobile Home (F622-049-000), for a complete list.

Remember: This contractor will be in your home for an extended period of time. Do plenty of research and hire a registered contractor before signing a contract for a major project. Examine the bid closely to ensure it has all the items you requested.

Roof

Roof shingles and other coverings

An L&I alteration permit is required.

In some cases, plan approval by L&I is required before construction begins.

Unfortunately, many fly-by-night companies offer super-low bids on roofing jobs by cutting corners and using inexperienced and uninsured labor. An uninsured worker who gets hurt means you could be liable for their medical bills. Be sure to hire a registered contractor.

See our publication, What You Should Know: Replacing the Roof on Your Manufactured or Mobile Home (F622-092-000), for more information.

Septic

Septic systems

No L&I alteration permit is required. You may need permits from your local jurisdiction or health department.

If your septic drain field is failing, carefully choose a specialized, registered contractor. The company that regularly pumps your tank, however, does not have to be a registered contractor.

Sheetrock/Drywall

Installing sheetrock/drywall?

An L&I alteration permit is required when installing sheetrock on walls and ceilings.

In most cases, plan approval by L&I is required before work begins.

See our publication, What You Should Know: Installing Sheetrock/Drywall on the Walls or Ceiling of Your Manufactured or Mobile Home (F622-099-000), for more information. Anyone you hire to do this type of work must be a registered contractor.

Remember: This contractor will be in your home for an extended period of time. Do plenty of research before signing a contract for a major project.

Solar Panels

Adding solar panels?

An L&I alteration permit is required.

To install solar-powered electrical and hot water systems, plan approval by L&I is required before construction begins.

See our publication, What You Should Know: Installing Solar Panels on Your Manufactured or Mobile Home, for more information.

Solar panel systems and hot water systems hooked into electrical or plumbing systems must be installed by a registered plumbing contractor and electrical contractor.

Storm Damage

Big storm? Trees or power lines down?

No L&I alteration permit is required for repairs.

If power lines are down, don't touch! The line could still be live and kill you. If you need more than a pruning topper to take down or cut up the trees or tree limbs, don't try it yourself — hire an experienced, registered contractor.

Stove/Fireplace

New wood or pellet stove, or fireplace?

An L&I alteration permit is required to install a wood stove, pellet stove or fireplace.

Make sure this item is installed by a registered contractor who knows insulation and clearance codes.

Subfloor

Replacing subfloor or floor joists?

An L&I alteration permit is required for repairing or replacing floor joists, trusses, or floor decking.

In some cases, plan approval by L&I is required before work begins.

See our publication, What You Should Know: Repairing the Floors in Your Manufactured or Mobile Home, for more information. Hire a registered contractor.

Remember: This contractor will be in your home for an extended period of time. Do plenty of research before signing a contract for a major project.

Water Heaters

Water heater installation or conversion?

An L&I alteration permit is required when water heaters are replaced or converted. See a list of other work requiring permits, such as extending gas piping.

A hot water heater can violently explode if not properly installed and maintained. Hire a registered contractor who employs certified plumbers. Check with your utility about any rebates that may be available.

Windows

Wall openings and framing for doors, additions, or windows

An L&I alteration permit is required for new and changed exterior openings.

No L&I alteration permit is required for replacing windows and doors fitting the old/existing openings. In some cases, plan approval by L&I is required before work begins.

See our publication, Adding or Changing Openings (F622-096-000), for more information.

Remember: Verify the contractor has posted a minimum bond and purchased liability insurance — and whether the company’s registration is up to date with L&I.

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