10', 20' & 40' Custom Containers

Your Space, Made Your Way

We started making portable offices with the knowledge that there ’s no easy way to do business from the dashboard of your truck. Our goal since 1998 has been to make convenient solutions, with a heavy focus on customer service and safety. Today, that means quality, rugged custom solutions in a variety of sizes that are way more than just storage or offices. Solutions can be customized in a number of ways, from our existing floor plans that can be made to order, or from a blank slate - conceived with your specifications.

Custom Office
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Built By Experts

Our process for custom builds starts with a solid framework, similar to our ruggedly-built standard designs. SiteBox Storage has more than 20 years of experience with this type of design and build process. We customize 10’, 20’, and 40’ sizes, either starting with one of our layouts, or from an open concept. Multi-section builds are also available, to give you even more space.

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Manufactured for Longevity

All of our custom units are equipped with high-quality finishes and ground-level access. Units are finished in one of our US-based production or fabrication centers, depending on the project. We use treated steel, which makes them water-resistant and pest-proof. Units are usually delivered with tilt-bed trailers, or they can be delivered and set in place utilizing a crane for the perfect placement on your site. Due to the structural design of the buildings, they can be placed on almost any level surface.


We have great standard storage and office configurations readily available, and now we’ve made customization easy too! These custom layouts have proven popular among customers, making it easier for you to get them quickly. These designs have been used in construction, manufacturing, retail sites, and even as portable labs. We don’t place any restrictions on their use and are always open to new ideas for custom projects.

Features and Options

Get what you need in a custom space! Each custom modification can include features like security windows, HVAC with temperature control, smoke detectors, and fire extinguishers. You can customize with options like ready-to-go desks with electrical and ethernet connections, stainless steel countertops, and many other material selections and finishes. Plus, using interior fast walls, we can section things how you like, creating offices, or space for storage. We can even add plumbing for the addition of restrooms or kitchens.

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