Think Outside the Box: The Advantages of Building a Custom Shipping Container Home

Choosing to build a custom shipping container home can be a very cool alternative to home construction. This past building code cycle, the international code council adopted shipping containers as a legitimate method for construction. All permitted containers have to follow the international residential code 2021. I plan to design and build one of the coolest luxury container homes for myself in the future. I want to share this knowledge with you and maybe you will want a custom container home yourself. There is a lot of potential for growth in this building method because of the infrastrure built around these containers for the import/ export of goods. It gives so much flexibility to the home creation process. Most consider these units to be trailers, which in part is true but it takes a different eye to see the potential of what these units can be. Think of the container home structure like an exoskeleton. Have you ever seen an ironclad beetle? Its body serves as its structure that houses all of the softer parts within. The shipping container’s cortex steel siding becomes the exterior siding for your home and everything else is built from within. There will be framing, insulation & drywall built on the interior surface of that corten steel container wall.

Unfortunately, I have to debunk a few myths about Shipping Container Homes first:

Myth #1: Shipping Container Homes are tiny homes / trailers

Shipping Containers come in a variety of sizes. The most standard sizes being 8’ x 40’ & 8’ x 20’ which means 320 SF & 160 SF, respectively. Using one singular container obviously will be tiny but these units can combine to create something substantial and interesting. Think of them like legos but keep in mind that the shipping container's strength is spread on all 4 corner posts. The structure would be compromised. These corner posts can never be removed and that serves as a limitation at times but within the constraints, luxury can be created. These units are essentially building blocks that are only bound by your imagination and creativity. Containers can even be designed to be ADA accessible.

Myth #2: Shipping Container Homes are the low cost solution

Contrarily to most beliefs, unless you’re building a shipping container home on your own somewhere in the back country that doesn’t require building codes, a custom shipping container home will not be the cheapest option. Everything that a normal home requires for construction has to be incorporated into the shipping container home. Trust me, there’s a lot that is required for any home to be approved by your local building department and that’s for your safety. Typically, a quality mid-luxury container home will average around $250-$270 / SF. That does not include the cost of your property or any site work. Also, be mindful that there are a lot of soft costs up front that are required before construction such as design, construction documents, structural engineering, fire sprinkler design, solar panels, utilities etc. If you're looking for a more inexpensive home solution, trailer park homes or modular homes with very inexpensive finishes might be a better direction.

Myth #3: You mean my home can be transported anywhere??

Yes in theory (post fabrication) until you’d like it to become a permanent residence. To get it built and approved in any state that abides by stringent building codes, the container home will have to be permanently fixed to a foundation. This means the home will be welded down to make sure it doesn’t get taken away in a natural disaster. This also helps lenders understand what they are giving you money for. The biggest question for lenders is in the fabrication stage. Your home will technically be personal property and not real estate until it is fixed to a permanent foundation.

Myth #4: Used Containers can be used for permitted construction

Unfortunately, the thought of repurposing used shipping containers that have sailed across the seas is not realistic. It's a noble concept but in areas like California, one can only construct a permitted shipping container home if the containers are new or a one trip container. That is for our safety. You wouldn't want a home made of something that has already taken stresses and loads. When taking a shipping container home into consideration, it is best to go with the new or one way trip. Although using new containers isn't as sustainable as recycling containers, there are still a few sustainable results that directly result from using the shipping container for a custom homes. The results include the repurposing containers for a holistic reasons....shelter. Everyone needs shelter. It's a fundamental human need.

It reduces waste by completing more in factory and reduces the average time of home construction. Stick built construction could be 12.5 months. Shipping container homes average around 8-12 weeks for construction.

Understanding all of this, the next question that people typically ask is: Why would I choose to build a Container Home over a traditional home since it isn’t necessarily cheaper?

The biggest advantage I’d say, is the speed of construction: 50% of the home’s structure is done in factory and can be installed on your property in less than a week. That can save you so much in labor costs. You will not have to completely rely on a contractor not showing up to build your home.

Durability / Ease of Maintenance: A container house is made of steel. It is very strong and built to withstand extreme weather on the ocean. Plus you don’t have to worry about pests ruining your house. No rat or termite will be biting through steel.

Eco-Friendly: Hundreds of thousands of containers are sitting on docks unused. Repurposing these containers not only reduces waste but it also reduces the footprint that you have on your property. We aren’t here to exploit the Earth, we should be working to live in harmony with Earth, only using the resources and space that we actually need.

Affordability / Customizable: Although the home construction process is expensive in general, using container homes gives you the freedom to have a luxury space designed to reflect to your living habits at a reasonable price range. There is complete flexibility in the design as long as it’s within the container’s natural restraints. This opens up opportunity for rooftop decks, balconies, courtyard spaces & even double-height spaces (i.e. tall ceilings).

Some of the biggest disadvantages that I've came across for this construction method is its novelty. The majority of lenders haven't dealt with this kind of construction before. Custom Container Home Building also requires a lot of capital upfront as companies such as Kubed Living would have to guide you through the building permitting process which includes having structural engineered drawings based on your custom shipping container home design. If you choose a cheaper (more difficult in most cases) property to build a home, you will end up paying for it in the long run. Hillside properties and properties that do not already have the utility infrastructure may run your bill up with electricity & sewer costs.

Aside from the building requirements that every new construction has to go through, shipping container construction is a very viable solution to your custom homebuilding needs. As I continue to improve and grow in my design prowess, I aim to move towards designing full modular housing communities. I will discuss what modular means in a different blog post. Factory built housing will be a game changer. Both shipping container & modular construction fall under this category. I'm working on finding the most optimal layout for both singles and families. Stay Tuned.

If you have questions, please reach out.

gueston@kubedliving.com

For your reference, shipping containers are now integrated into the IBC 2021. You can read it below

2021 International Building Code (IBC)

SECTION 3115 (Special Construction) INTERMODAL SHIPPING CONTAINERS

The provisions of Section 3115 and other applicable sections of this code shall apply to intermodal shipping containers that are repurposed for use as buildings or structures, or as a part of buildings or structures. Exceptions:

1. Intermodal shipping containers previously approved as existing relocatable buildings complying with Chapter 14 of the International Existing Building Code.

2. Stationary storage battery arrays located in intermodal shipping containers complying with Chapter 12 of the International Fire Code.

3. Intermodal shipping containers that are listed as equipment complying with the standard for equipment, such as air chillers, engine generators, modular data centers, and other similar equipment.

4. Intermodal shipping containers housing or supporting experimental equipment are exempt from the requirements of Section 3115, provided that they comply with all of the following:
   

4.1. Such units shall be single stand-alone units supported at grade level and used only for occupancies as specified under Risk Category I in Table 1604.5.

4.2. Such units are located a minimum of 8 feet (2438 mm) from adjacent structures, and are not connected to a fuel gas system or fuel gas utility.

4.3. In hurricane-prone regions and flood hazard areas, such units are designed in accordance with the applicable provisions of Chapter 16.

3115.2 Construction documents. The construction documents shall contain information to verify the dimensions and establish the physical properties of the steel components and wood floor components of the intermodal shipping container, in addition to the information required by Sections 107 and 1603.

3115.3 Intermodal shipping container information. P CDP Intermodal shipping containers shall bear an existing data plate containing the following information as required by ISO 6346 and verified by an approved agency. A report of the verification process and findings shall be provided to the building owner.

1. Manufacturer's name or identification number.

2. Date manufactured.

3. Safety approval number.

4. Identification number.

5. Maximum operating gross mass or weight (kg) (lbs).

6. Allowable stacking load for 1.8G (kg) (lbs).

7. Transverse racking test force (Newtons).

8. Valid maintenance examination date.

Where approved by the building official, the markings and existing data plate are permitted to be removed from the intermodal shipping containers before they are repurposed for use as buildings or structures or as a part of buildings or structures.

apps3115.4Protection against decay and termites. Wood structural floors of intermodal shipping containers shall be protected from decay and termites in accordance with the applicable provisions of Section 2304.12.1.1.

3115.5 Under-floor ventilation. The space between the bottom of the floor joists and the earth under any intermodal shipping container, except spaces occupied by basements and cellars, shall be provided with ventilation in accordance with Section 1202.4.

3115.6 Roof assemblies. Intermodal shipping container roof assemblies shall comply with the applicable requirements of Chapter 15. Exception:Single-unit, stand-alone intermodal shipping containers not attached to, or stacked vertically over, other intermodal shipping containers, buildings or structures.

3115.7 Joints and voids. Joints and voids that create concealed spaces between connected or stacked intermodal shipping containers at fire-resistance-rated walls, floor or floor/ceiling assemblies and roofs or roof/ceiling assemblies shall be protected by an approved fire-resistant joint system in accordance with Section 715.

3115.8 Structural. Intermodal shipping containers that conform to ISO 1496-1 and are repurposed for use as buildings or structures, or as a part of buildings or structures, shall be designed in accordance with Chapter 16 and this section.

3115.8.1 Foundations. Intermodal shipping containers repurposed for use as a permanent building or structure shall be supported on foundations or other supporting structures designed and constructed in accordance with Chapters 16 through 23.

3115.8.1.1 Anchorage. Intermodal shipping containers shall be anchored to foundations or other supporting structures as necessary to provide a continuous load path for all applicable design and environmental loads in accordance with Chapter 16.

3115.8.2 Welds. New welds and connections shall be equal to or greater than the original connections.

3115.8.3 Structural design. The structural design for the intermodal shipping containers repurposed for use as a building or structure, or as part of a building or structure, shall comply with Section 3115.8.4 or 3115.8.5.

3115.8.4 Detailed design procedure. A structural analysis meeting the requirements of this section shall be provided to the building official to demonstrate the structural adequacy of the intermodal shipping containers. Exception:Intermodal shipping containers designed in accordance with Section 3115.8.5.

3115.8.4.1 Material properties. Structural material properties for existing intermodal shipping container steel components shall be established by material testing where the steel grade and composition cannot be identified by the manufacturer's designation as to manufacture and mill test.

3115.8.4.2 Seismic design parameters. The seismic force-resisting system shall be designed and detailed in accordance with one of the following:

1. Where all or portions of the corrugated steel container sides are considered to be the seismic force-resisting system, design and detailing shall be in accordance with the ASCE 7, Table 12.2-1 requirements for light-frame bearing-wall systems with shear panels of all other materials.

2. Where portions of the corrugated steel container sides are retained, but are not considered to be the seismic force-resisting system, an independent seismic force-resisting system shall be selected, designed and detailed in accordance with ASCE 7, Table 12.2-1.

3. Where portions of the corrugated steel container sides are retained and integrated into a seismic force-resisting system other than as permitted by Item 1, seismic design parameters shall be developed from testing and analysis in accordance with Section 104.11 and ASCE 7, Section 12.2.1.1 or 12.2.1.2.

3115.8.4.3 Allowable shear value. The allowable shear values for the intermodal shipping container corrugated steel sheet panel side walls and end walls shall be demonstrated by testing and analysis accordance with Section 104.11. Where penetrations are made in the side walls or end walls designated as part of the lateral force-resisting system, the penetrations shall be substantiated by rational analysis.

3115.8.5 Simplified structural design of single-unit containers. Single-unit intermodal shipping containers conforming to the limitations of Section 3115.8.5.1 shall be permitted to be designed in accordance with the simplified structural design provisions of Section 3115.8.5.2.

3115.8.5.1 Limitations. The use of Section 3115.8.5 is subject to the following limitations:

1. The intermodal shipping container shall be a single-unit, stand-alone unit supported on a foundation and shall not be in contact with or supporting any other shipping container or other structure.

2. The intermodal shipping container top and bottom rails, corner castings, and columns or any portion thereof shall not be notched, cut, or removed in any manner.

3. The intermodal shipping container shall be erected in a level and horizontal position with the floor located at the bottom.

4. 4.The intermodal shipping container shall be located in Seismic Design Category A, B, C or D.

3115.8.5.2Simplified structural design. Where permitted by Section 3115.8.5.1, single-unit, stand-alone intermodal shipping containers shall be designed using the following assumptions for the corrugated steel shear walls:

1. The appropriate detailing requirements contained in Chapters 16 through 23.

2. Response modification coefficient, R = 2.

3. Overstrength factor, Ω0 = 2.5.

4. Deflection amplification factor, Cd = 2.

5. Limits on structural height, hn = 9.5 feet (2900 mm).

3115.8.5.3 Allowable shear. The allowable shear for the corrugated steel side walls (longitudinal) and end walls (transverse) for wind design and seismic design using the coefficients of Section 3115.8.5.2 shall be in accordance with Table 3115.8.5.3, provided that all of the following conditions are met:

1. The total linear length of all openings in any individual side wall or end wall shall be limited to not more than 50 percent of the length of that side wall or end wall, as shown in Figure 3115.8.5.3(1).

2. Any full-height wall length, or portion thereof, less than 4 feet (305 mm) shall not be considered as a portion of the lateral force-resisting system, as shown in Figure 3115.8.5.3(2).

3. All side walls or end walls used as part of the lateral force-resisting system shall have an existing or new boundary element on all sides to form a continuous load path, or paths, with adequate strength and stiffness to transfer all forces from the point of application to the final point of resistance, as shown in Figure 3115.8.5.3(3).

4. Where openings are made in container walls, floors or roofs, for doors, windows and other openings:

4.1 The openings shall be framed with steel elements that are designed in accordance with Chapters 16 and 22.

4.2 The cross section and material grade of any new steel element shall be equal to or greater than the steel element removed.

5. A maximum of one penetration not greater than 6 inches (152 mm) in diameter for conduits, pipes, tubes or vents, or not greater than 16 square inches (10 323 mm2) for electrical boxes, is permitted for each individual 8-foot (2438 mm) length of lateral force-resisting wall. Penetrations located in walls that are not part of the lateral force-resisting system shall not be limited in size or quantity. Existing intermodal shipping container vents shall not be considered a penetration, as shown in Figure 3115.8.5.3(4).

6. End wall doors designated as part of the lateral force-resisting system shall be welded closed.