Here are our observations on the technology;
- It is a form of recycling: An empty 40′ shipping container weighs between 3000-4000kgs. Taking a mean/average of 3500 kgs and we allow for an embodied energy of 20 Mega Joules/ 5.55 kilowatt hours per kg, you can clearly see a lot of energy was used to create it. Furthermore, for every kilogram of steel, a whopping 1.37 kgs of harmful CO2 is emitted into the atmosphere. So, if you are a tree-hugger, recycling a container will ensure that energy doesn’t go to waste and living in it may be good for you.
- Fast to construct: Container houses can be up and in use in a matter of days. (https://www.youtube.com/watch?v=yl9FE3iyTKU ) This is useful in specific situations like during a disaster or other emergencies.
- Mobility: Big advantage. Container houses can be moved with ease. This can be useful during disasters and emergencies or in areas difficult to access. It can also house temporary structures that house services like parcel services, mobile post offices, mobile clinics (controversial ey?), mobile offices etc.
- They are great when they house offices/ premises etc. where you don’t own/ have leased the land.
- Containers are modular. They have fixed dimensions and any cost-effective use of them will require that one is constrained within the fixed sizes. This is of course a complete turn off. Imagine being served some nyama choma at Njuguna’s or Saitoti’s and then you are told by the waiter, ‘buda, kula tu Mahûngû, matharigo na pembe, usikule mbavu na gîchiri. (Just eat the hooves, lower legs and horns, but leave the tantalizing ribs and scapula). Yes, you will have eaten some choma, but you will not enjoy it to the maximum. Same for your container house, you will be restricted.
- Additional STEEL reinforcement: The more one plays with containers in the design (in search of the ‘elusive’ creativity/being different/ departure from ‘kawaida Kenyan architecture’), by puncturing or tearing away the container walls, there will be more need to reinforce the stacked containers (if it is a storied building). Steel frames are a costly affair, if it was cheap everyone would be building in steel. From our past observations and experience, the roofs/floors of these containers do need extra reinforcement to function safely. More steel, higher costs.
- Fantastic conductors, hopeless insulation: The interior is hot when it is hot and cold when it is cold. Your house will basically be a sauna by day and a freezer by night. You must insulate them to get some degree of thermal comfort. Insulation, costs more money. Insulation materials also have excessively high embodied energy and carbon emissions during their manufacture. This makes such housing potentially ‘environmentally unfriendly’. Also note that, the most effective climate control would be to air-condition the container, which is more costs in installation and power bills. Also ensure that you have grounding rods/earth wires at 2 opposite corners of the container. But more importantly, door opener/levers must be insulated. You can imagine the shock you will get when you are just minding your own business opening the door levers and lightning strikes.
- Electrical and data trucking, conduits, water pipes, soil vent pipes: These we must all agree are mandatory for any house to function like a 21st century house. You are not going to build a house in the 21st century in Nairobi and sorely rely on ‘choo ya shimo’ that is at the corner of your plot. You will most likely need a water closet inside. It’s worth noting that these pipes and conduits need space to run. A container is already quite space constrained and hence introduction of concealed pipes and conduits, makes spaces smaller. Repairs of the same can also prove to be tricky and of course costly.
- Quality of containers: Have you ever asked yourself why these containers are being sold/dumped in the first place? Is it that the shipping companies have closed down? Or the goods are no longer being transported? We don’t know since we are not in the transport business. However, from our observation, most containers that we want to buy cheap have defects. Have you ever wondered why most container houses you see have another mabati/tin roof on top of it?
- When well done, it has no cost savings than ‘conventional’ construction methods.
Container houses or offices are great. However, Housing is hardly a building technology problem. Building technology should be driven first and foremost by environmental conditions. Have you ever gotten into a mud hut with grass thatch? Is there any more comfortable house (thermally not elapidae-speaking) than these huts? We are yet to find one.
Every geographical region has got a material they can use for construction and further positively respond to the environment. In Nairobi, there are plenty of rocks, in Kisumu and Kampala, clays are available for bricks, In China, bamboos are available. Build to respond to your environment not be caught in multiple marketing gimmicks.
Members of our profession have also been criticized for not ‘thinking out of the box’. This may be partially true, but we also wouldn’t want to recommend triangular tires for your car because we are bored of circular wheels. Creativity has very little to do with the actual material use. Creativity is expressed through responses to contextual, economic, cultural, social and aesthetics aspects. This means one can have a creative mud hut and a very bland house made in fancy steel.
As we leave to engage in social distancing, remember the same way you go to a doctor to seek treatment, ensure you engage the construction ‘doctors’ before you start your mjengo. Don’t listen to pseudo construction consultants in these streets of Mukuru kwa Zuckerberg.
Prevention is better (and way cheaper) than cure. Cure in construction is a terminal disease. You will be curing and repairing forever. You can take that to the bank.