Box Truck with Cab Access: How to Add One

When most people think of a box truck with a cargo container, they picture nothing more than a delivery vehicle. You have seen them—a truck cab in the front and a big rectangular box on the back end. But what if I told you these vehicles can do much more?

Box trucks can be converted into highly functional spaces. Many DIYers are upgrading their rigs to create a box truck with cab access, which allows you to move directly from the cab into the cargo area.

This small change opens the door to countless possibilities. With a pass-through, you can enjoy safer overnight parking, turn your rig into a comfortable home on wheels, or transform it into a mobile workshop. Cab access turns an ordinary box truck into a true multipurpose vehicle.

What Is a Box Truck with Cab Access?

A box truck with cab access features an opening—often called a pass-through—that connects the truck cab to the rear cargo box. Operators can move from one space to the other without ever stepping outside. It is both useful and convenient.

This modification is essentially a cut-out, sometimes framed and fitted with a sealed accordion boot system. The accordion boot flexes as the truck moves, keeping the compartments connected and weather-tight.

Why Add Cab Access to a Box Truck?

There are several reasons to add cab access to a box truck. It is about more than convenience—it improves functionality, safety, and unlocks new uses for your vehicle.

Sleeping Berth for Long Hauls

For long-haul drivers, adding a sleeping berth is a common upgrade. In a box truck, a small room can be built at the front of the cargo box, separated from the load. With a pass-through, you can step into the sleeper and rest without leaving the vehicle. This is a huge safety benefit when parked at a busy rest stop or in a questionable neighborhood.

Tiny Home Conversion

With rising housing costs, more people are turning to tiny homes—and box trucks are a popular choice for DIY builders. A box truck with cab access functions much like a motorhome. The pass-through lets you walk directly from the driver’s seat into your own kitchen, bathroom, or sleeping area, making the whole truck feel like one cohesive living space.

Mobile Workshop

Contractors, mechanics, and tradespeople often convert box trucks into mobile workshops. With cab access, you can grab tools, store gear, and get back on the road quickly—without constantly climbing in and out of the vehicle.

Mobile Office or Business

Beyond workshops and homes, a cargo box can be outfitted as a mobile office, recording studio, or even a film-editing station. The box is essentially one large, customizable room where you can add equipment and furnishings to suit your needs.

How to Add Cab Access

If you are planning to create a box truck with cab access, here are some proven methods to do it right:

Cutting the Pass-Through Hole

Decide where the opening should go and determine the size. Both openings (cab and box) need to line up exactly. Corners should ideally have a rounded radius, but 45-degree angles can also work. If you cut through metal, seal the edges to prevent rust.

Creating an Attachment Flange for the Boot

Once the opening is cut, you will need to prepare the edges to accept the accordion boot.

• If the walls are thin (sheet metal or fiberglass under 3/16”), you can install directly.
• If the walls are thicker, fabricate a flange to hold the boot securely.

Helpful resources:

• Flange Options for Accordion-Boot Pass-Throughs
• How to Fix the “Too Thick Wall” Problem When Installing an Accordion Boot
• How to Modify an Accordion Boot for Flat Surface Mounting (Step-by-Step Guide)

Installing the Accordion Boot

The best way to connect the cab and box is with a rubber accordion boot. These flexible boots allow movement between compartments while keeping out water, dust, and wind.

Made from durable EPDM rubber, accordion boots come in different expansion sizes. You will need to measure the gap between the cab and box to select the right one. Leave a little slack to allow for flex. Once in place, the boot clamps securely onto the flange with an embedded metal clip.

Helpful resources:

• Rubber Boot Gasket Comparison Chart
• Calculate Measurements for Your Accordion Boot – Online Calculator

Optional Framed Door

Consider adding a door to your pass-through for privacy and security. Options include pre-fabricated doors or custom builds, with swing or sliding (pocket-style) operation. A door also helps reduce noise from the cargo box. Go here for Cab to Camper Spacing Pass-Through Frame

Things to Consider

Before creating a box truck with cab access, keep these factors in mind:

• Structural Integrity: Cutting into the cab wall can weaken it—reinforce as needed.
• Weatherproofing: Use quality seals, like an accordion boot, to block rain, dust, and wind.
• Legal Compliance: Some modifications may require inspection or adherence to local vehicle codes.
• DIY vs. Professional: Skilled DIY builders can do the work, but commercial kits and installers provide a cleaner, more reliable finish.

Conclusion

Upgrading to a box truck with cab access is a major step in improving functionality. From adding a sleeper berth to building a tiny home or creating a mobile workspace, this simple modification transforms how your truck works for you.

By connecting the cargo box to the cab, you create a single, unified space that is safer, more practical, and easier to use every day. The possibilities are only limited by your imagination.

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