Custom Shipping Containers Built for the Way Texas Works
Climate controlled job site trailers to rugged industrial boxes — Steel Box manufactures and supplies ready-to-go custom containers throughout Central Texas. We take pride in not having a “cookie cutter” solution here at Steel Box. We build what YOUR project needs, built from the ground up. From design to fabrication, electrical, and delivery right to your Texas job site ready to start day one — we do it all in house.
CHOOSE YOUR CONTAINER SIZE
One of the first steps in designing your custom build is knowing what size container you need. If you are unsure of what size container your build will require we will walk you through your options.
20ft Shipping Container – New
160 sq ft of functional spacePerfect for custom jobs. Small enough to squeeze into that tricky job site or private lot but roomy enough to become a well-stocked office, safe workshop, or storage container. Light enough to move and relocate with ease as your work progresses.
Ideal for: Office space on job sites, tool storage, secure equipment rooms, small retail kiosks.
20ft Used Shipping Container
160 sq ft of functional spacePerfect for custom jobs. Small enough to squeeze into that tricky job site or private lot but roomy enough to become a well-stocked office, safe workshop, or storage container. Light enough to move and relocate with ease as your work progresses.
Ideal for: Office space on job sites, tool storage, secure equipment rooms, small retail kiosks.
20ft High Cube Shipping Container
Additional 12" Overhead ClearanceStandard 20ft width, but with almost a foot of additional headroom. Great if you need clearance to run duct work, hoist equipment overhead, or you simply like things a little more spacious.
Ideal for: HVAC rooms, tall storage racking, mechanical room conversions, donation collection stations.
40ft Shipping Container – New
320 sq ft of usable spaceNeed more space? Got it. The 40-footer provides your crew with ample room to spread out. A full-size crew breakroom, office/storage facility, or oversized industrial enclosure with multiple doors — all possible with the extra footprint of a 40ft standard container.
Ideal for: Crew spaces, oversized workshops, buildings with multiple doors, expandable operations facilities.
40ft Used Shipping Container
320 sq ft of usable spaceNeed more space? Got it. The 40-footer provides your crew with ample room to spread out. A full-size crew breakroom, office/storage facility, or oversized industrial enclosure with multiple doors — all possible with the extra footprint of a 40ft standard container.
Ideal for: Crew spaces, oversized workshops, buildings with multiple doors, expandable operations facilities.
40ft High Cube Shipping Container
12" of Top Headroom EverywhereThe blank canvas of containers. High cubes come with a full 12" of vertical headspace across the entire 40ft footprint. This opens up possibilities to build interior partitions, mezzanine decks, run ductwork, and create complex industrial designs that simply wouldn't fit inside a standard-height container.
Ideal for: Modular laboratories, machine shops, E-Houses, extra tall storage/offices, industrial shells.
Modifications We Can Make
We do all custom fabrication ourselves. Below are some of the additions we can cut, weld, wire and paint onto your container.
Entrances
- Steel person fit doors (single, double)
- Heavy duty roll-up garage style doors (standard height, high door)
- Equipment ramps with built in forklift pockets
- Outdoor stairways and landing platforms
- Padlock boxes and lock-proof handles
Views
- Sliding vinyl windows
- Stationary glass windows
- Drive-through teller windows
- Bars and guards for added safety
- Skylights to brighten up office conversions
Heating & Cooling
- Through the wall window air conditioners (regular efficiency)
- Mini-split heat pumps (energy star models)
- Central HVAC with ductwork
- Louvered intake and exhaust vents
- Industrial exhaust vent fans
Power & Lights
- Full electrical hook-ups (100A or 200A service)
- 220V outlets for power tools
- LED recessed and surface mount lighting
- Duplex outlets integrated
- Wire management with conduit
Interior Surface
- Wall panels: framed/plywood
- Wall panels: FRP sheets for cleanable surfaces
- Insulation options: Batt or spray foam
- Flooring: vinyl plank or laminate overlays
- Floor coatings: epoxy for workshops
Storage Solutions
- Industrial shelving: fixed and adjustable
- Pipe hanging racks
- Partition walls and pass-through doors
- Fold down workbench and tables
- Custom cabinet frames
Exterior Options
- Painted exterior (Any color! We have industrial coatings)
- Container sandblasting and rust conversion
- Decals and logos
- Color matching for company fleets
Built for Your Industry. Delivered to Your Door.
Need some inspiration for your next shipping container project? Shipping containers can be used in countless ways on a job site, property or commercial lot. Here are some custom builds we’ve completed over the years — including who we built them for.
Construction & Contracting — Job Site Mobile Office
Construction crews require a workspace that’s built tough enough to handle the abuses of a job site. We take containers to the next level with a steel personnel door, sliding vinyl windows, through-wall HVAC, full electrical package (breaker panel, LED overhead lighting, duplex outlets), epoxy floor coating. The result? A climate-controlled, wired-ready workspace that arrives ready to plug into your generator. No setup crew required.
Trades & Field Services — Office / Storage Combo
Need an office and storage for equipment/materials but have them on the same lot? We’ve constructed containers with one side featuring insulation, wall finishing, HVAC, interior LED lighting, and electrical outlets.
Workers can access this end via steel personnel door. The opposite side of the container features a heavy-duty roll-up door and is finished with an equipment ramp for easy loading and unloading (no forklift needed).
Other Build Examples
Construction & Contracting — Tool & Parts Storage Container
It can be difficult to keep tools and equipment secure on an active construction job site. Custom lockable storage containers with heavy-duty roll-up doors make it easy for crews to load/unload equipment. We also install interior LED lighting, wall-mounted pipe rack systems for vertical storage, and welded tamper-resistant padlock boxes on the exterior. Custom built to store everything your crew needs in one place, then secure and lock up at the end of the day.
Industrial & Manufacturing — Equipment Room
Heat and humidity aren’t friends of sensitive electronics, control cabinets, and industrial machinery. Turn shipping containers into a sealed, temperature-controlled equipment room with a steel entry door, mini-split HVAC system, full insulation and interior wall finishing, and custom electrical breaker panel. Built to spec to securely house your equipment and provide comfortable room for technicians to work.
Industrial & Manufacturing — Mobile Operations Unit
There are times when a project needs both a staffed workspace and secure storage container, but in the same physical space. We’ve got a solution. Simply split the shipping container interior into two sections with a pass-through doorway. Fully outfit one-half with insulation, interior wall finishing, climate control, LED lighting, and electrical outlets. Setup the other half as secure equipment storage area. Exteriors can be painted to match your existing fleet, or containers can be wrapped with company graphics.
Trades & Field Services — Mobile Workshop
Contractors who travel between job sites need a mobile workshop they can take with them. We’ve built fully enclosed workshops with side-loading roll-up doors, complete LED overhead lighting, welded trailer hitch, 200-amp electrical service with 240V outlets for heavy equipment, insulated walls, and epoxy coated flooring. Roll up when you’re done for the day and arrive at your next site with an organized, clean workshop.
Energy & Infrastructure — Equipment Enclosure
Generators, pumping stations, compressors, and other industrial equipment deserves a secure, ventilated home. We fit containers with oversized roll-up doors for easy access when servicing, roof mounted louvered exhaust vents, HVAC, and epoxy flooring. Our industrial containers ARE functional FIRST. No finished interiors. No bells or whistles. Just tough enough to protect your equipment while keeping it accessible.
Small Business & Specialty — Custom Machine Shop
Indie fabricators, machine shops, and specialty operators need to plan out how your shop will build out. We can outfit containers with finished interiors, install LED task lighting above work spaces, include ductless mini-split HVAC, 240V power, and weld in framing along the walls to allow you to attach your workbenches. Moveable when you’re done for the day and ready to start work at your property.
Why Choose Steel Box Shipping Containers?
Crafted with Care. Shipped with Pride. Supported by People Who Care.
Steel Box is a locally owned container building company located in Texas. Our main service areas include Austin, San Antonio, Round Rock, San Marcos, Georgetown and other cities in between. When you work with Steel Box, you’re not dealing with a national company that sends your call to a regional center. You’re talking to homegrown Texas owners and employees who really care when you have a question about your build schedule or need an instant decision on that last minute tweak to your design.
- Fabricated In-house. No Outsourcing Your Build.
- Transparent Quotes. Line item pricing with no hidden fees at delivery.
- Delivered to You. No delivery to a staging yard.
- Single Point of Contact Representative. You deal with the same person from quote to delivery.
We deliver custom shipping containers across Texas
Modified Container FAQs
Got questions about modified shipping containers? We've answered a few.
A modified container is a shipping container or storage container that has been altered with additional features, special design elements, and/or structural changes which allow it to be used as something besides (or in addition to) a generic storage cube. Modifications can be as simple as adding a personnel door and electrical outlets or as involved as a full build-out (insulation, HVAC, interior framing to allow for custom floor plans, wall partitions, paint finish, etc.).
Either way, the result is a structure that's built to your needs — an office, workspace, equipment enclosure, or retail container — built around the strong steel frame of a shipping container.
Container modifications are alterations made to a shipping container. This can include:
- Cutting new windows and doors
- Installing HVAC
- Running electrical
- Insulating and finishing walls
- Adding floor overlays
- Painting the exterior
- Welding on door access ramps or stairs
Modifications can be as simple as adding a lock box and roller door, or as complex as completely finishing the interior and welding on custom HVAC units. Basically, a container modification is what turns a locked metal box into your portable workspace.
Sort of. Some modifications are pretty DIY-friendly. But drilling into and welding on the steel walls, adding electrical, and making structural modifications is a different ball game. Specialized tools, structural knowledge, and welding experience are required for those kinds of mods. You can easily ruin the structural integrity of a container by cutting into it incorrectly.
Here at Steel Box, we do all of our modifications in-house so we can guarantee the structural integrity of your container. We'll talk to you every step of the way, but for complex modifications we don't trust the build to just anyone.
We modify all sizes and types of containers, but the four most popular are:
- 20ft Standard — the go-to for single-user offices and simple storage builds
- 40ft Standard — more space for larger workshops or split-use office/storage builds
- 20ft High Cube — an extra foot of headroom, ideal for equipment rooms or complex interior builds
- 40ft High Cube — maximum space and clearance for the most involved custom projects
Let us know what you have in mind and we can help you choose the right size for your project.
Almost every aspect of a shipping container can be modified:
- Exterior: doors, windows, paint, stairs, ventilation & vent covers, ramps, lock boxes
- Interior: walls (insulation and finishing), floors (overlays and coatings), ceilings, wiring, electrical components, lighting fixtures, HVAC, shelving, partition walls, and workbench supports
There are very few aspects of a container that can't be customized to fit your needs. The only limit is structural integrity. We know where not to cut.
We modify:
- 20ft standard containers
- 40ft standard containers
- 20ft high cube containers
- 40ft high cube containers
Those cover just about any project we've worked on. If you have a situation with non-standard dimensions or unusual space requirements, give us a call and we'll walk you through what's possible.
Nope. Many customers know exactly what they want their container to do, but aren't sure how to make that happen. Start with the "why" — how will you be using your container? Who needs access? Will you need power or HVAC?
Tell us what you need and we'll design a custom modification plan that fits your project. If you already have drawings or specific dimensions, that's great too. Either way, we've got you covered on the design front.