The word conex (sometimes spelled CONEX) is short for "container express," a term coined by the United States military in the 1950s for a standardized steel shipping container used to move equipment and supplies during the Korean War. The original CONEX boxes were 8.5 feet by 6 feet by 6.8 feet, much smaller than today's intermodal units, but the principle was identical: a stackable, lockable, weatherproof steel box that could move by truck, rail, or ship without unpacking.
By the late 1960s the commercial shipping industry had standardized on 20-foot and 40-foot intermodal containers (the units you see on every cargo ship and rail line today). The military term stuck in everyday speech, and conex is still used for any large steel storage box, even when the unit is technically an ISO shipping container or a purpose-built storage container.
For practical buying purposes the three terms describe the same thing in Greater Houston, the Woodlands corridor, Katy, Sugar Land, and the Ship Channel cities of Pasadena, Baytown, and Deer Park: a corrugated steel container, 20 or 40 feet long, with cargo doors on one end, designed to keep wind and water out for decades.
Conex Box vs Shipping Container vs Storage Container
The vocabulary lines up like this:
Conex box. Originally a military-spec container. In modern use, a colloquial name for any steel shipping container used for storage. Applied to 20-foot and 40-foot units in residential and contractor settings.
Shipping container. The technical term for an ISO-standard intermodal container. These are the units that cross oceans on cargo ships. They are built to ISO 1496 specifications, which dictate dimensions, lifting points, and structural strength.
Storage container. A general retail and rental term used by ground-storage companies. Often refers to the same intermodal unit, but the phrase also covers purpose-built ground-level containers that have never seen ocean service.
If you are shopping for storage, the difference rarely matters. The same physical unit can be sold as any of the three. What matters more is the size, the condition grade, and the delivery logistics.
Standard Conex Box Sizes
The standard sizes are:
20-foot standard. Length 20 ft, width 8 ft, height 8 ft 6 in. Roughly 1,170 cubic feet of interior space. The interior floor is about 19 ft 4 in by 7 ft 9 in, with 7 ft 10 in of height.
40-foot standard. Length 40 ft, width 8 ft, height 8 ft 6 in. Roughly 2,350 cubic feet of interior space. Best for contractors, ranches, and businesses.
40-foot high cube. Length 40 ft, width 8 ft, height 9 ft 6 in. The extra foot of headroom adds about 350 cubic feet of usable space, which matters when you store racked goods or tall equipment.
Specialty sizes (10-foot, 45-foot, refrigerated, double-door, side-opening) exist. Ask about availability when you request a quote.
Uses by Industry
Uses in Texas include:
Oilfield tool, chemical, and PPE storage at yards. Steel walls, lockable doors, and on-site placement provide secure storage at the work site.
Hurricane-prep storage for documents, heirlooms, and inventory in flood-prone ZIPs. Long-cycle uses where the container becomes part of the operation, not a temporary fix.
Construction jobsite storage on long-cycle Houston builds (Katy, Cypress, the Woodlands). Project-driven needs where timing, access, and short-term affordability all matter.
Acreage and ranch storage in Waller, Montgomery, and Fort Bend counties. Permanent storage for the things a garage or barn cannot fit.
How to Choose the Right Conex Box
Three questions narrow the decision:
How much space do you need? Photograph what you intend to store. A 20-foot unit holds the contents of a household storage unit, the materials for one residential framing job, or about ten standard pallets. A 40-foot unit doubles that.
How clean does the interior need to be? If you are storing tools, equipment, or boxed goods, a used wind-and-water-tight unit is fine. If the unit will be converted to an office, a workshop, or a clean-room storage space, a one-trip unit saves the cost of repainting and floor refinishing later.
Will it move? If the container will sit on a single property for the whole life of its use, buying makes sense. For a project that ends in a few months, compare the cost of renting from a rental company with the cost of buying.
How Delivery Works in Texas
Container One offers tilt-bed delivery and Customer Assist delivery for conex boxes. With tilt-bed delivery, the trailer tilts back and the container slides onto the ground. With Customer Assist delivery, a chain connects the container to an anchor point you provide on site. The container slides onto the ground as the trailer pulls away. A delivery follows three steps:
Site check. You confirm the access route, the placement spot and the overhead clearance before delivery. A 20-foot delivery needs 110 feet of straight clearance and at least 15 feet of driving clearance, with 22 feet of clearance along the entire unloading path. A 40-foot delivery needs 130 feet of straight clearance.
Surface check. Concrete, asphalt, gravel, hard-packed dirt, and grass all work. Soft, waterlogged, or steeply sloped ground may need preparation.
Final placement. The driver positions the truck and places the container at the spot you choose when the truck has the space it needs. Container One does not move a container once it is set down.
Permits and Local Rules
Permit rules depend on the municipality. Urban codes are stricter, and some HOAs prohibit container placement entirely. Before ordering, check with your local building or planning department, and verify HOA rules if applicable. Our guide to permits in Texas explains when permits apply: Container permits in Texas.
What a Conex Box Costs in Texas
Pricing is ZIP-specific because delivery distance drives a meaningful portion of the total. Tell us your ZIP and what you need, and a Container One sales representative will send back a written quote that lists the delivery and container charges.
Frequently Asked Questions About Conex Boxes
For everyday Texas buying purposes, yes. Conex started as a military term and is now used colloquially to describe any steel storage container, including standard ISO shipping containers.
It depends on the delivery route and the placement spot. A 20-foot delivery needs 110 feet of straight, unobstructed space, at least 15 feet of height for driving, 22 feet of height along the entire unloading path, and at least 10 feet of width. If your lot is tight, send a photo when you request a quote.
Yes. Modifications include doors, windows, ventilation, electrical, insulation, and interior framing. We sell modified units and can quote custom builds. See modified containers in Texas.
Container One's warranty follows the grade. New / One-Trip units carry a 10 year structural and 10 year no-leak warranty, Cargo Worthy and Wind and Water Tight units carry a 5 year structural and 5 year no-leak warranty, and Economy units carry a 1 year roof leak warranty. Container One provides the warranty. Written warranty terms.
It depends on your municipality and any HOA rules. Confirm them for your address with your local building or planning department before ordering.