Off-Site Construction Units Types

Modular/Industrialized Home

Modular 2 story - home guide
Modular/Off-Site 2-Story Home – Photo Courtesy of HomeGuide

Applicable Code – International Residential Code (IRC)

Definition of Unit – A structure that:

  • Includes One and Two-Family Dwellings and Accessory Structures to Dwelling Units
  • Constructed offsite in a climate-controlled setting
  • Constructed of Closed Construction (Local Authority is unable to perform inspections without disassembly or destruction of the units)

Summary of Program Requirements

  • Licensing of Manufacturing Facility (Per state requirements)
  • Quality Assurance Manual Required
  • Plan Approval (Each Model & Each State)
  • Certification Inspections may be required per individual state requirements (100% inspection of construction)
  • Ongoing Inspections per individual state requirements (Every Unit)

HUD Manufactured Home

Applicable Code – Department of Housing and Urban Development (HUD) 24 CFR Part 3280

Definition of Unit – A structure that:

  • Transportable in one or more sections
  • Min 8’-0” wide (traveling mode)
  • Min 40 feet long
  • 320 Sq Ft or more
  • Built on a permanent chassis
  • Used as a dwelling with or without a permanent foundation
  • Does Not include any self‐propelled recreational vehicles

Summary of Program Requirements

  • Licensing of Manufacturing Facility
  • Quality Assurance Manual Required
  • Plan Approval (Each Model)
  • Inspections (Every Unit in a stage of construction)

Recreational Vehicle (RV)

Recreational Vehicle (RV)

Applicable Code – NFPA 1192

Definition of Unit – A structure that:

  • Intended for travel or seasonal use including recreational and camping
  • Has motive power or is towed
  • Regulated by NHTSA (National Highway Traffic Safety Administration)
  • Local zoning requirements may limit placement to areas of recreational use

Summary of Program Requirements 

  • NTA IM 039 Recreational Vehicle Program
  • Quality Assurance Manual Required
  • Manufacturing Facility Certification Required- 100% Inspection for 1st unit (min.) and quarterly audits (min. 4 per year)
  • Manufacturer Certified Units
  • Plan Review Optional

Modular/Industrialized Unit

Modular Multi-Story Construction
Modular/Off-Site Multi-Story Appartment Building

Applicable Code – International Building Code (IBC)

Definition of Unit – A structure that:

  • Includes Multi-Family Dwellings and Commercial Structures.
  • Constructed offsite in a climate-controlled setting.
  • Constructed of Closed Construction (Local Authority is unable to perform inspections without disassembly or destruction of the units)

Summary of Program Requirements 

  • Licensing of Manufacturing Facility (Per state requirements)
  • Quality Assurance Manual Required
  • Plan Approval (Each Model) (Each State)
  • Certification Inspections may be required per individual state requirements (100% inspection of construction)
  • Ongoing Inspections (Each Unit) per individual state requirements

Park Model RV

Photo Courtesy of Titan Factory Direct

Applicable Code – ANSI A119.5

Definition of Unit – A structure that:

  • Intended for recreational, camping, or seasonal use.
  • On a single chassis mounted on wheels
  • Gross trailer area not exceeding 400 sq. ft. in setup mode
  • Gross trailer not exceeding 320 sq. ft. or width greater than 8.5 ft. in transport mode
  • Local zoning requirements may limit placement to areas of recreational use

Summary of Program Requirements 

  • NTA IM 040 Park Model Recreational Vehicle Program
  • Quality Assurance Manual and Homeowners Manual Required
  • Manufacturing Facility Certification Required- 100% Inspection for 1st unit (min.) and quarterly audits (min. 4 per year)
  • Manufacturer Self Certified Units
  • Plan Review Optional