Are shipping containers the solution to sustainable, affordable housing?

by | Jan 11, 2023 | Blog | 1 comment

Written by Jennifer Crawford

As a registered architect who has been working in the construction industry for over 25 years, I’ve worked in architectural practice, for large construction companies, land developers, commercial builders and project home builders.

TL:DR – No.

There has been a trend over the last few years for shipping containers to be put forward as a really great solution to affordable housing.  Indeed I have been asked quite a few times by potential clients if I would help them with a shipping container home.  I haven’t done one yet.

Why is this?  Well, for one the conversion of shipping containers is a bit of a niche market.  If I thought it was the right thing to do then I would jump in with both feet.  But it’s not.  Why?  Let’s take a more detailed look.

The modern version of shipping containers were first designed in the 1950s with refinements over the next 20 years so that the standardised shipping containers that we know today began common use in the 1970s.  Their original intent was to reduce double handling at ports and allow for the efficient transport of goods around the world on container ships and then on trucks and trains.  They do this job very well.  They are durable and standardised so that they can be reused over and over again.  They weren’t designed to be lived in.

As a result they have an opening at one end to allow for goods to be loaded and removed.  The structure of the container is as efficient as it can be to transport goods.

Now when it comes to spaces to live in, they have entirely different requirements.  For spaces to live in we need light and air and some flexibility of sizes for those spaces and their use.  We also need services such as electricity and water to be able to live in them.

To begin with, it’s the size of a shipping container that’s one of it’s biggest constraints. With an internal width and height of less than 2.4 metres but a length of just under 6 metres that gives you a rather small, elongated space.  Maybe great for a pop-up cafe kitchen but not so good to live in.   The ceiling height for a start is less than that required in the building codes.  Yes, people have stuck a couple together but this needs serious changes to the structure of each that then needs to be reinforced again to get the structural performance back to where it needs to be.

Then we come to the question of insulation.  Shipping containers are basically an empty metal box so leaving one of those outside in the sun or out in the cold means that the interior temperatures can vary wildly depending on where they are.

So just add insulation, right?  Well if you insulate on the inside, you lose valuable space.  We previously looked at how they are not that big to start with.  Also if you insulate on the inside you can end up with all sorts of moisture, condensation and mould issues that no one wants to live with.  This is due to the difference in temperature between the inside and outside and how vapour and moisture move (or don’t move) between the two.

So insulate on the outside then?  Yes, you can do that but then you need to reclad the outside and you have lost that industrial aesthetic that you were probably going for when you thought of using a shipping container in the first place.

Next, we need openings.  Yes windows and doors.  So we cut holes in the structure to place those windows and doors.  We need to be careful with flashings and sills and the like to reduce the possibility of water penetration.  Also, cutting large holes in the structure then reduces the structural integrity of the box that was meant to transport goods.  We need to modify the structure to restore that structural integrity which all costs money.

We also need to get the shipping container to site.  Is it nearby or is it hundreds of kilometres away?  Transport costs are real.

Are we using a recycled shipping container or a brand new one?  If we are using a brand new one then any sustainability brownie points go out the window.  We are no longer using an otherwise waste product but a product that was built specifically for us.  What is the difference between this and just building a new structure whether or not it is prefabricated?

If we are using a recycled container, then how do we know what was transported in it previously?  It could have had some pretty nasty things inside it that you may not wish to live with.  As containers are painted with chemicals to withstand marine conditions on ships, some of those paints and finishes may not be so great to have around you 24/7.

There’s also issues of potential previous damage or corrosion to a used shipping container that may impact on its performance as a habitable structure.

We now have to service the container with electricity and water supply and sewer disposal.  All of these need to be retrofitted to a shell that wasn’t intended for this purpose.  Yes I know a few containers have been placed in off grid locations and you can use solar panels for electricity and tank water for water supply but we still need to get these into the container for use.  Maybe we have an outside composting toilet to avoid the need for sewer connection.  Those have their place too.

A shipping container used as a home will still require approval if it is intended to be lived in so there is no free kick in terms of speeding up approval processes.

And now we come to the kicker – cost.  Unfortunately to do all of this retrofit and modification work it still costs money.  Maybe even the same as a traditional build.  It’s highly unlikely to be much cheaper.

So when you are buying a shipping container for housing, what are you getting?  You are effectively getting a size constrained skin that needs to be adapted and modified significantly for comfortable habitation.

If you are being given one for free and you know where it’s been, have a suitable site for it, only need a small space, have the skills to modify it and the budget to do it then go for it!  They can look very cool on YouTube videos.  I don’t want to stop you but I’ll pass.  Thanks.

Written by Jennifer Crawford

As a registered architect who has been working in the construction industry for over 25 years, I’ve worked in architectural practice, for large construction companies, land developers, commercial builders and project home builders.

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1 Comment

  1. Helen

    Brilliant article. Thank you. I’d love a similar blog about kit homes. You hear strong opinions against them but they sound better than shipping containers!


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