Are Container Homes Sustainable?

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Container homes can be sustainable if chosen correctly without chemicals or rust, treated and insulated properly and planned structurally well. Several shipping containers are either left idle or expend a lot of energy to melt and reuse the steel. However, it is arguable that metal should be left for purposes only metal can best fulfill. There are also issues on the toxic chemicals used that will be health damaging, as well as the structural integrity and comfort left of containers after repurposing it into a home.

Image from Eco Shipping Container Home in the Bush – House for Rent in Wattle Bank, Gippsland, VIC, AU | Riparide

The eco-living trend of shipping container homes has taken off in the past decades. Container homes have emerged as this solution to reuse long, large boxes of steel around the world that otherwise would have occupied precious space or end up in the landfill.

Here we’ll look at the good, bad, ugly and upside down of these eco homes.

What we do know is that countries constantly ship goods overseas, and often these containers are either not to quality standard for another trip on sea, or are too expensive to send back to the seller empty. This leaves thousands or millions of these giant steel boxes taking up large amounts of space on the docks. If not reused or recycled it goes discarded, which would take a massive amount of energy to burn.

“According to a report by the Cambridge University Press, up to 3 billion shipping containers are produced every year. The lifespan of an average container is about 12 years, and most spend at least some of this time sitting unused. Needless to say, this is a waste of space as well as steel, a material that requires a lot of energy to extract and manufacture.” (1)

Containers as homes are viewed as sustainable for making use of the already existing metal shell as the building framework. This saves us from sourcing new, non renewable materials from the earth such as clay from topsoil, wood that contributes to deforestation and brick that requires a lot of power. A tremendous amount of energy is always expended on producing and refining these materials. (1)

When shipping containers need to be discarded and melted for steel reuse, this requires an extensive amount of energy spent. One container would spend around 8,000 kWh of energy, through an electric arc furnace or basic oxygen furnace. Compare this to the 400 – 7,600 kWh of energy needed to renovate the container into a livable home.

Image from Amy | Riparide – Book a short nature escape

With the rapid development of technology, environmentally friendly insulation material has made the market: (1,2)

  • Insulated wall board or paneling;
  • Well insulated flooring/ceiling options;
  • Ceramic coating and polyurethane foam insulation; and
  • Low VOC paints, primers, adhesives and sealants.
  • Green roofs
  • Straw bales (an agricultural byproduct)

Unfortunately, the less eco-friendly options for insulation like spray foam tend to be more effective for these metal boxes. (3)

Proper insulation can give your container home greater energy efficiency. As with any home, there are green building strategies that increase the sustainability factor of your home:

  • Energy efficient appliances
  • Ethically sourced wood
  • VOC free materials
  • Water saving faucets
  • Composting System
  • Solar Panels
  • Rainwater reuse/harvesting
  • Smart Home Sensors
  • Sourcing local materials and labor
Image from Are Container Homes Sustainable? | 5 Great Ways to Make an Eco-Friendly Container Home | Container Home Hub

These containers have a ISO size standard of 8 feet wide by 8.5 feet high, with the length varying at 20 or 40 feet. These measure just right for an average person’s height. By reusing containers, we reduce the amount of new building materials being harvested and manufactured, saving the container itself and our future home demolition from being thrown. The less cement we can have in a project the better. The cement industry is one of the largest polluters of carbon dioxide.

“The amount of construction waste is expected to double by 2025 to 2.2 billion tonnes.”(4)

Image from How Environmentally Friendly are Shipping Container Homes? (tigershippingcontainers.com.au)

What Makes Container Homes NOT Sustainable?

Through the years container homes have gained popularity but also been up for debate especially in the realm of sustainability.

Just to play on both sides, here’s an overview of why some folks think container homes aren’t the way to go.

Maximizing Metal’s Use on Earth

Metal is often preferred as a structural element, like your beams and post. As a surface material, it becomes less desirable being so easily heated or cooled. In the case of container homes, the insulation is not just on the walls. You have to cover as much metal as you can to prevent it acting as a thermal bridge for heat transfer.

This is the same caution one must take in stacking containers. All metal surfaces must be insulated to prevent the heat loss or gain through thermal bridging. (5)

Another argument is that metal is a material we can recycle over and over. Producing new metal is more energy intensive in extraction and heavy on the carbon footprint to manufacture. Therefore, we must use the metal we’ve already made for functions that only metal can perform or is better suited to. (6)

When built well, a solid wood house can be just as strong.

Issue on Health

The container home innovation does pose a lot of eco-friendly factors. However, one must be extremely cautious of the container itself. Many containers may have been used to ship toxic chemicals, pesticides or treated to resist corrosion and rust, which can be hazardous to our health. (7)

Containers are usually coated with lead-based paint to withstand the salty air and water in the oceans. They can be toxic to your health. This is one of the reasons why a lot of shipping container home building companies are using brand new containers instead of using the older unused containers as they are very toxic.” (5)

Loss of Function

Another issue would be that in order to make container homes comfortable, insulation and an HVAC system would be needed to be put in place. This however results in a great reduction of space, totalling to a room width of 2.17 meters. With the added comfort systems, the container’s height will also be reduced to below the building code’s habitable room height requirements.

Most of the effective insulation that occupies less interior space are the less eco-friendly options. Try opting for CFC free foam sprays. (6)

An additional roof would have to be built for lack of strength and protection. Yes! Get a roof for your container home.

The corrugation of the container also gives it its resilient strength. When we begin to cut through the metal for a window or door, we lose the structural integrity and need to reinforce it, which would add to the cost.

Summary

All the points above may be true, but I always believe any decision is based on context. Maybe your climate requires less treatment? Perhaps your community really does have a lot of containers with no use for it. Maybe you’re using it as a guest house, home office, or in hybrid with your home and not entirely of container.

What is your take on it? Do you live in a container home? Do you know someone who does? There’s nothing better than getting the first hand experience yourself while bearing the points in mind.

Image from Pinterest

Resources:

  1. Attainable Home. (2021, December 10). Are Container Homes Sustainable? we weigh the considerations. Attainable Home. Retrieved August 2022, from https://www.attainablehome.com/are-container-homes-sustainable/
  2. Tiger Shipping Containers. (2021, October 17). How environmentally friendly are shipping container homes? Tiger Containers. Retrieved August 2022, from https://www.tigershippingcontainers.com.au/how-environmentally-friendly-are-shipping-container-homes/
  3. Marshall, L. (2021, November 3). Shipping Container Homes Explored: One-key™ blog. ONE. Retrieved July 2022, from https://onekeyresources.milwaukeetool.com/en/are-shipping-container-homes-cheaper
  4. Kiil, R. (2022, March 30). Why and how shipping container houses are environmentally-friendly? Eco-friendly, Pre-built and Mobile Tiny House I Popuphut. Retrieved August 2022, from https://popuphuts.com/why-and-how-shipping-container-houses-are-environmentally-friendly/
  5. Eco Abode. (2020, June 21). 5 reasons shipping container homes are not sustainable. Eco Abode. Retrieved August 2022, from https://ecoabode.com.au/eco-building-guides/shipping-container-homes/
  6. Reynolds, M., & Cosgrove, E. (2020, March 1). Are shipping container homes good or bad? Ecohome. Retrieved August 2022, from https://www.ecohome.net/guides/1152/shipping-container-houses-modern-looking-compact-and-recycled-but-good-or-bad/
  7. Barber, M. (2020, April 10). Everything you need to know about shipping container homes. Curbed. Retrieved July 2022, from https://archive.curbed.com/2020/4/10/21165288/shipping-container-house-build-cost