What to Look for When Buying a Shipping Container

Shipping containers are increasingly being used as the building blocks of homes, ADUs, and vacation properties. While containers are built to be durable, not all containers are created equal, and choosing the right one is critical when it will be used as a living space.

If you’re shopping for a shipping container to convert into housing, here are the most important things to look for before you buy.

1. Container Condition and Grade

Shipping containers are typically sold in different condition grades. For housing, condition matters more than appearance alone.

Common grades include:

• New / One-Trip: Used once for shipping, minimal wear

• Cargo-Worthy (CW): Structurally sound and suitable for transport

• Wind and Water Tight (WWT): No holes, no leaks, solid doors

• As-Is: May have structural issues or damage

For residential use, one-trip or high-quality WWT containers are usually the best choice. They minimize repair work and provide a solid starting point for modifications.

2. Rust, Corrosion, and Structural Integrity

Surface rust is common and usually not a problem, but deeper corrosion can compromise the container’s strength.

Inspect for:

• Heavy rust on roof panels

• Rust-through on walls or floor

• Soft spots or holes in steel

• Damage to corner castings or frame rails

Structural integrity is especially important if the container will be stacked, joined with others, or heavily modified.

3. Floor Condition and Materials

Most shipping containers have plywood floors treated with pesticides to protect cargo during international shipping. This is an important consideration for housing.

Look for:

• Solid, undamaged flooring

• No rot, delamination, or strong odors

• Options to remove, seal, or replace the floor if needed

Many container home builders choose to remove the original floor entirely and install a new subfloor designed for residential use.

4. Container Size and Configuration

The size you choose affects layout, cost, and livability.

Common residential-friendly options:

• 20-foot containers: Good for studios or compact units

• 40-foot containers: Better for full living spaces

• High Cube containers: Extra height (about 1 foot taller), ideal for insulation and ceilings

High Cube containers are often preferred for housing because they allow for better headroom after insulation and finishes are added.

5. Doors, Seals, and Weather Tightness

Doors are one of the most vulnerable parts of a container.

Check for:

• Smooth door operation

• Intact rubber gaskets

• No daylight visible when doors are closed

• No signs of water intrusion

Even if the original doors will be removed, water-tightness is still a good indicator of overall condition.

6. Previous Use and Cleanliness

Knowing how a container was previously used can help avoid problems later.

Ask about:

• Prior cargo types

• Exposure to chemicals or hazardous materials

• Odors or stains inside the container

Containers used for food-grade cargo are often preferred for residential conversions.

7. Modifications and Customization Potential

Not all containers are equally suited for modification.

Consider:

• Wall flatness and straightness

• Structural alignment

• Ease of cutting openings for windows and doors

• Suitability for joining with additional containers

Starting with a straight, undamaged container reduces fabrication time and costs.

8. Delivery Access and Placement

Buying the right container also means ensuring it can be delivered to your site.

Before purchasing, consider:

• Site access for trucks or cranes

• Ground conditions

• Local placement regulations

• Foundation requirements

A reputable container supplier should help you plan delivery logistics as part of the purchase process.

9. Compliance and Documentation

For housing projects, documentation matters.

Look for:

• Container identification numbers

• Proof of ownership

• Condition certifications if required

• Compliance with local building department requirements

Having proper documentation can make permitting and inspections much smoother.

10. Work With a Knowledgeable Supplier

Perhaps the most important factor is who you buy from.

A good container supplier will:

• Help you choose the right container for housing

• Be transparent about condition and history

• Offer delivery coordination

• Understand residential and ADU use cases

Buying the cheapest container isn’t always the best decision when it’s going to become someone’s home.

Start With the Right Container

A successful container home starts long before construction, it starts with selecting the right container. By focusing on condition, size, structural integrity, and supplier expertise, you can avoid costly surprises and set your project up for success.

If you’re considering a shipping container for housing and want help selecting the right unit, our team is happy to answer questions and guide you through the process.