Manufactured homes in Washington must be installed by an L&I certified installer. Installation work includes all aspects of installing the home, starting with the construction of the foundation, through assembly of the home, connecting the home to utilities and the application of the skirting.

Get Certified

Submit an application and pay the fee

  • The Installer Training and Certification Application Form (F622-086-000) must be filled out and mailed with payment to the address shown on the form.
  • Applications must be received by the application cut-off date. Early application is encouraged. Applications received after the cut-off date may be scheduled for the next available class due to time and/or class size limitations.
  • Applicants will not be registered for the certification training and examination until their application has been approved.

Application & fees

Type of Fee Fee
Application Fee — Training, Exam, Certification (manual included) $321.80
Application Fee — Training Only (manual included) $160.80
Retake Failed Exam & Training $48.10
Certification Renewal $160.80
Continuing Education Class $64.10
Training Manual on Flash Drive $15.90

Take the training and pass the exam

The Manufactured/Mobile Home Installer Training Course is a comprehensive course that includes a 3-hour examination. Courses are held a minimum of 4 times throughout the year.

To become a certified manufactured home installer in Washington State, an individual must meet the following requirements:

  1. Meet experience qualifications.
  • 6 months hands-on installation experience under the supervision of a certified installer; or
  • 2 years hands-on experience in residential or commercial construction.
  1. Submit an application and fee.
  2. Attend the 12-hour training course.
  3. Take and pass the certification examination.

See the training schedule.

About the examination

The manual for the training course can be downloaded at the link below.

Manufactured Home Installer Training Manual
Supplemental Handout

This manual is updated when changes occur in the laws relating to manufactured home installation. Department of Labor & Industries (L&I) staff also review and update the manual annually. Any suggested changes to this manual or the course in general will be seriously considered and should be submitted in writing to Department of Labor & Industries, Manufactured Home Installer Training and Certification Program, PO Box 44420, Olympia, WA  98504-4420.

The Q&A session and proctored exam will be conducted on the dates provided on the schedule below.

To allow appropriate study material review there is an “Application Cutoff Date” posted with the exam dates. Your application and fees MUST be received prior to the cutoff date to be added to the exam roster.

It is extremely important to include your email address on the application. We will send all information to you at this address. First, we will send you a link to the Training Course Video. We highly recommend you prepare yourself for the exam by watching the video in portions over several days so you can give it your full attention and take notes for reference during the exam.

The Zoom link will be emailed the week prior to the exam to the email address provided on the application. This email address will also be used for sending out the exam.

During the examination you are required to have your video camera turned on so we can witness you taking the exam. At the completion of the exam, you will be graded, and your score revealed.

A passing score of a minimum 70% grants your status as a certified installer. The final paperwork will be processed within a few days and your certification card will be mailed to you.

It is an open-book examination covering material addressed in the installer training course. A score of 70% or higher is required for certification. Applicants receiving a passing grade on the examination will become certified Washington State manufactured home installers. An installer certification license will be issued.

Auditing the training course

Anyone may take the training class without taking the examination for certification. “Training Only” is offered at a reduced cost and attendees receive a certificate of attendance. This option is particularly useful for individuals who would like specific knowledge about installation but do not need certification.


Manufactured/Mobile Home Installer Training/Examination Schedule (All classes will be held remotely unless otherwise noted).

Class Dates Location Class Times Application Cutoff Date
August 20, 2024​    Zoom​​​ 8 -10 a.m. Q&A session
10 a.m. - 1 p.m. Proctored exam​​​
August 6, 2024​
November 19, 2024​    Zoom​​​​ 8 -10 a.m. Q&A session
10 a.m. - 1 p.m. Proctored exam​​​​
November 5, 2024​
January 16, 2025   Zoom​​​​​ 8 -10 a.m. Q&A session
10 a.m. - 1 p.m. Proctored exam​​​​​
January 2, 2025
March 13, 2025   Zoom​​​​​ 8 -10 a.m. Q&A session
10 a.m. - 1 p.m. Proctored exam​​​​​
February 27, 2025
May 22, 2025   Zoom​​​​​ 8 -10 a.m. Q&A session
10 a.m. - 1 p.m. Proctored exam​​​​​
May 8, 2025
August 14, 2025   Zoom​​​​​ 8 -10 a.m. Q&A session
10 a.m. - 1 p.m. Proctored exam​​​​​
July 31, 2025
November 13, 2025   Zoom​​​​​ 8 -10 a.m. Q&A session
10 a.m. - 1 p.m. Proctored exam​​​​​
October 30, 2025

Note: Classes are held via ZOOM. Applicants will need access to a computer as well as a camera for the 3-hour exam.

Application and payment must be received no later than the cutoff date for the class requested. Applications received after the cutoff date may be scheduled for the next available class due to time and/or class size limitations.


Installer certification must be renewed every 3 years

Certified installers must do the following prior to expiration of their certificate:

Pay your renewal fee online

A renewal notice and application form will be mailed to each installer approximately 45 days prior to their expiration date. The renewal application and payment must be received by L&I on or before the installer's certification expiration date.

A certified installer who fails to do this must reapply for installer training and certification and meet all requirements for certification.

Installer Certification Renewal Form (F622-085-000).

Continuing education is required for renewal

Installer certification is valid for 3 years. Certified installers must attend a continuing education course to qualify for certification renewal. Certified installers must complete their required continuing education and the renewal application process prior to expiration of their certificate.

Continuing education classes available

Manufactured/mobile home installer continuing education schedule

All classes will be held via Zoom unless otherwise noted.

Class Date Location Class Time Registration Cutoff Date
Purchase Labels

Certified Installers must apply their WAINS label to any manufactured home they install and may be purchased by completing the application and submitting with the fee. Usage is reported monthly to us. Labels are assigned to individual Installers and may not be used by anyone else or transferred without submitting a completed form to L&I.

Forms for installers

Verify Installer

Verify your installer — Ask to see their certified manufactured home installer card or certificate with their certification number and verify the expiration date. Or you can verify your certified installer using our online tool.

Installation Requirements

Any individual or company that is paid to install a manufactured or mobile home must be certified to perform the installation (Chapter 43.22A RCW). This includes dealers, manufactured or mobile home park owners, and contractors.

Supervision and installer certification tag requirements

A certified manufactured home installer must be on site at all times during each phase of installation. Different installers can supervise each phase of installation. Licensed plumbers or electricians working within the scope of their license do not need additional supervision or certification.

Certified manufactured home installers must place a red metallic Washington Installer (WAINS) certification tag, issued by L&I, on each home they install before it is inspected by the local jurisdiction. This tag must list all installation work performed by the installer. One tag is required for each installer. For example, if one installer sets the forms and pours the concrete runners and another installer performs all other installation work, there should be two tags affixed to the home. These tags should be placed directly above or below the HUD certification label, or temporarily located in plain sight within 3 feet of the home's front entry. Tags can only be removed by the homeowner after the local enforcement agency has issued its final approval.

Manufactured and mobile homes in Washington State must meet the installation requirements of WAC 296-150I.

New homes

New manufactured homes must be installed according to the manufacturer's instructions, or the specific instructions of an engineer or architect licensed in Washington. These specific instructions do not need to address the entire installation - the manufacturer's installation instructions can be used for other installation aspects. If neither the manufacturer's installation instructions nor the specific instructions cover all aspects of installation, it must comply with the requirements of WAC 296-150I-0310.

Relocated manufactured and mobile homes

If the home manufacturer's original installation instructions are unavailable, relocated homes can be installed according to the specifications of the Manufactured Housing Construction and Safety Standards (MHCSS 3285) or the specific instructions of an engineer or architect licensed in Washington. For information on where to obtain a copy of MHCSS 3285, contact our Factory Assembled Structures toll-free automated services line at 1-800-705-1411 (Option 3).

Local City and County Requirements

The installation of all manufactured/mobile homes are inspected under permits issued by the local cities and counties. Cities and counties enforce the manufactured home installation rules per RCW 43.22.440. The manufacture set up manual for new homes must be available for the local building inspector to use. For relocated homes, if the setup manual is not available, the requirements in MHCSS 3285 or instructions approved by a Washington registered professional engineer must be used.

The local building department may set installation requirements for: flood plains, hazardous areas, earthquake protection, frost line, soil bearing, noise control, fire sprinklers, wildfire protection, and snow loads. The local building jurisdictions must provide options for meeting the snow load requirement. All structures in the jurisdictions must meet the same requirements.

An installation checklist for local building inspectors can be obtained by contacting the Installer program at 1-800-705-1411 Option 3 or email

Alterations to new and relocated homes are inspected by L&I. Auxiliary structures such as porches, decks, garages and room additions built next to the manufactured home require permits from the local building department. When auxiliary structures impose additional loads on the manufactured home a permit from L&I is required for the load bearing changes.

State laws and rules for manufactured/mobile homes

RCW 43.22 — Sections 335-495 — Manufactured/mobile homes, factory-assembled structures
RCW 43.22A — Mobile and Manufactured Home Installation
WAC 296-150I — Manufactured Home Installer Training and Certification Program, Installation Code
WAC 296-150M — WA Manufactured Home Code