20' x 28' Standard "Quick-Ship" Modular Building

Save costs, labor, and materials with modular construction. PortaFab's "Quick-Ship" modular units come as two, three, or four wall buildings created from your selection of either the OmniFlex Plus steel or Series 300 aluminum stud framing systems.

20x28 foot modular building

[4-Wall Building]

20x28 foot 3-wall modular building

[3-Wall Building]

20x28 foot 2-wall modular building

[2-Wall Building]


Our complete prefab kits include everything needed for a basic modular inplant office. All models include the following:

  • Interchangeable wall panels (Thermal or Fire & Sound panels)
  • Acoustical drop ceiling
  • Steel roof deck
  • Framing: Wiring posts, corner posts, top and bottom channels
  • Connecting hardware
  • Pre-hung steel door with or without window

20' x 28' "Quick-Ship" Building Specifications

Product Specifications
Width (Feet) 20' 4 1/2"
Depth (Feet) 28' 4 1/2"
Height (Feet) 8' or 9'
Color / Finish Champagne, Grey, White
Approval / Regulations Thermal Panel: R-13, STC-24
Fire & Sound Panel: R-11, STC-31 (Class A per ASTM-E84)
Assembly Unassembled
Clearance Height Interior 7' 6"
Door Size 3' x 7'
Door Style Swing
Frame Construction Painted Steel or Aluminum
Light Fixtures 8 (based on 4-wall building configuration)
Outlets 8 (based on 4-wall building configuration)
Limited Warranty 1 Year
Type 4-Wall, 3-Wall or 2-Wall
Wall Construction Standard thermal panels consist of 1/4" vinyl hardboard on polystyrene core or fire and sound (F&S) panels with 1/2" vinyl gypsum on polystyrene core
Wall Thickness (Inches) 3

Additional Specifications:

  • Wiring Posts - Omniflex Plus steel (in champagne, grey, or white) or Series 300 aluminum.
  • Non-progressive system.
  • Galvanized floor track.
  • Vinyl-base interior and exterior.

Review the steps for purchasing a modular building to learn more about how to choose the prefabricated building that is right for your business.


Options for "Quick-Ship" Units

Doors and Hardware
Steel Door Assembly
  • 3070 - 20 Gauge Steel Door Assembly - Flush
  • 6070 - 20 Gauge Steel Double Door Assembly - Flush
  • 1/4" Clear Tempered Safety Glass
  • Aluminum Threshold - 3"
  • Lever Lockset (standard duty)
Door Louver
  • Door Louver - 16" x 12"
Msc Hardware
  • Door Closer
  • Kickplates


Window Assemblies
Fixed Window
  • 4' or 2' nominal width x 3' nominal height glazed with 1/4 clear tempered safety glass.
Sliding Window
  • 3' x 3' nominal dimensions, installed in wall panel glazed with 1/8" clear tempered safety glass.


Roof and Ceiling Systems
Acoustical Ceiling
  • 2' x 4' x 5/8" mineral fiberboard with white steel grid system
Ceiling Insulation
  • 6" Fiberglass (R-19) (144 SF per roll)
Roof Deck
  • Up to 12' length
  • 16' long dust cover support beam
  • 20' long dust cover support beam
  • Dust cover support angle - 12' (must be used along all existing building walls)


Climate Control
HVAC Units
  • 11,600 btu cool/11,300 btu heat (230V)
Air Conditioning Units
  • 7,900 btu (115V)
Baseboard Heaters
  • 1,500 watt - 120V
Framed Cutouts
  • Installed or material only (size not to exceed 12 l.f.)


Electrical Components
Light Fixture
  • 2' x 4' flourescent (4-bulb) fixture, T8 ballast (bulbs not included)
Outlet or Switch
  • Outlet without Wiring (15V)
  • Switch without wiring (15V)
Circuit Breaker Boxes
  • 4-Space
  • 6-Space
  • 10-Space
Exhaust Fan
  • 270 cfm ceiling mounted exhaust fan - Includes fan, duct kit, and switch (louver in door is recommended for maximum air flow)

Learn more about our Modular Wiring Package.


Back to standard "Quick-Ship" units page

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