Detailed info about building shipping container structures
There are designs that make overall financial and practical sense and those that do not. At the present time, Hi-cube shipping containers are quite expensive in Hawaii, and yet some designs make financial sense even with the high cost of containers.
Here are your options if you want to work with us: You can simply purchase containers from us completely unmodified –OR- we can modify them to whatever extent you want and deliver them to your home site –OR- Manage your entire project (we are not licensed Contractors, but we can manage your project) –OR- Help you enlist a General Contractor and consult with that person if desired. If you want to finance your project, you must enlist a Licensed Contractor. Bonding the job is very difficult, but we have made arrangements with one company in Hawaii that will bond your container structure.
Hi-cube steel containers are best for building structures: They have a net interior ceiling height 8’ 11” and a standard container’s ceiling height is one foot less than that at 7’ 11”. Many people want refrigerated insulated containers. If you are wanting a permitted home, you are wise not to use them because inspectors need to inspect inside the walls, which is not possible. They have interior walls with polyester insulation inside already, so you cant weld anywhere due to insulation catching fire, you cant run wiring or plumbing inside the walls. Theoretically, one could put electrical via metal conduit pipes mounted on the outside of those inside walls and avoid any welding, but how ugly would that look? The aluminum container is a lot weaker and more expensive than a steel one, the reefer unit takes up a lot of space and has to be removed, etc. We doubt seriously that the county would permit their use for a home, no homes have been approved to our knowledge using them. Steel containers are easy to work with, and the easy to apply ceramic exterior coating gives you outstanding heat insulation by reflecting heat before it heats up the exterior steel surfaces. Combining that coating with ventilating skylights and windows for good ventilation gives you a home every bit as cool as a conventional wood home with minimal or no termite worries. We further recommend that you insulate and drywall the interior walls for further insulation against heat and cold, also giving you a quiet home that is easy to clean. You can go with no insulation and drywall, but then you have to look at the corrugated walls, clean around that corrugation where it meets the floor and stare at electrical conduit pipes, outlets and light fixtures. Some folks insist on doing things this way, citing concerns about mold in the walls. This is actually a valid concern. Single wall virtually eliminates any bad effects of condensation, including mold and rust. You still get condensation but it is very easy to deal with. Metal structures with insulated walls are more prone to condensation problems, which generally makes one more prone to rust, and possibly mold. Condensation also occurs in wood structures. The only solution is ventilation. Air vents can solve the problem. A removable baseboard is a great idea, allowing you to check for moisture on the floor of the wall cavities. Gravity pulls moisture down to the ground and mainly causes rust. We can advise you on condensation issues. With no insulation inside, it gets very cold at night. Your body heat radiates right thru any single wall structure. If you follow our advice on treating surface rust, your steel containers will last for many decades.
Steel containers, also referred to as cans, are very strong. However, if you cut out entire 40’ long walls, which is what many of our plans offer, you do need vertical support or roof trusses for direct support. If you try to make a living space that is one can wide, you live in a 7’ 6” space, which we think is generally too narrow. We understand that some of you want the lowest cost structure possible, and single wide spaces would be the lowest cost and simplest to build. Click here to see our latest single container home design that is legal and permittable. We were able to get a bldg permit for a one container home in April 2008. This kind of project would allow one to put a roof over their heads and add-on later legally. We are designing one can projects with multiple sliding glass doors for a super-wide opening, with adjoining enclosed lanai, or retreactable awning. This really opens up that one can home nicely. With the enclosed lanai option, this allows you to have much more built-ins and countertop space etc inside. Without the enclosed lanai, those elements are very minimal to comply with code pertaining to minimal required amt of unencumbered interior space. When you join two cans together and cut out the two walls that touch each other, you end up with a 16’ wide space, three cans gives you 24' width, etc., which we feel is a lot nicer to live in. Our first project utilizes two cans side by side and cut out for a 16 x 40 interior space. It has 2 legal bedrooms, one bathroom, a very nice kitchen with massive countertop space and real wood cabinets. Plans are on this site now, click here to see them!
Don’t used containers have dents and rust? Generally they do. Ours tend to have less than most, but the dent issue is a probem with county inspectors. Even though we have nice used cans, you are much better off purchasing new ones if building a home or any structure that you want to permit. This is because county inspectors do not like dents or rust, and have actually shut down projects made from used containers. Just about every used container has been in service for 8 years, so the steel sub-floor has rust all over it, and in about 12-15 years, the sub-floor will crumble, and there goes all that money invested in your home. We actually guarantee success with your permitted structure if you use new cans, and do not if you elect to build with used ones. We greatly encourage taking off the double doors and welding up that end for several compelling reasons- The County hates them, bugs can crawl around the rubber gaskets and infest, many folks think they look ugly and complain to the county, making it harder to build container homes. Also- if you have cans on site for storage or whatever, they must be removed from your property before final inspection. They will not issue final otherwise, it is a pet peeve of the county.
Cans are also very secure. There are many plans out there that put the cans separated apart and bridge them with traditional wood based materials. The main problem we have with these designs is you loose security when you build long sections out of wood, and you also compromise the termite proof nature of the structure. For plans where cans are separated, we weld metal across those gaps that we salvage from cutting out interior walls. Also, we plan on offering thick metal pieces that completely cover all windows and lock up securely so you can really secure your structure if you plan on being away for long stretches of time. When you leave, you have the option of locking up very securely, eliminating any chance of breaking in through wood. There would effectively be no wood to cut through and no windows to break into. This option comes with a price tag of course, but for some, it is well worth it. That being said, if someone really wants in, they will get in, and others will break into another house that is easier to get into. Such is life…
How does electrical work? For Insulated homes, we run BX conduit which fits inside of the walls, with outlets and lighting fixtures that are flush to walls just like a conventional home. For those not wanting insulation and interior walls, code forces you to run ugly metal conduit pipes that you see running to all outlets and lights. We work with the electrician and his electrical plans, and do only what he prescribes. Most often, they allow us to run wire and connect to outlets and light fixtures, and he inspects everything. Law states you must have a licensed electrician and plumber who pulls those permits, draws those plans, and takes legal responsibility for his work.
What about Plumbing? No problem. Again, you run your plumbing like any other structure. Keep in mind, often it is essential to cut away some steel structure from the can's floor, which takes a bit more time to do. Where there is plumbing, we have framed walls to hide pipes and offer an easy surface to mount essential things in those bathroom and kitchen areas. If off-grid on water catchment, you may need to run an electric water pump to maintain workable water pressure. This consumes tiny amts of power and is not a problem. In catchment scenarios, we recommend a water purifying system with sufficient strength ultra-violet lamps to kill parasites, bacteria and etc. Catchment water has parasites due to insect exposure, bird droppings and rats. For catching water from your roof, we like the look of traditional, trussed A-frame type roofs, but they add a lot of cost to the project. They make your structure look like a real home and are really great, but increase costs. However, we can create anything custom that you might want. Shed style roofs are a lot less expensive and provide a clean and easy way to catch water. Our designs direct all the water to one long end of the roof and one 40’ long gutter collects all the water and directs it to your storage tank. Standard metal roofing is used for the best overall look and reasonable cost. Another option is to make a roof from plywood and coat with elastomeric coating and polyester fabric meshed inside of that heat reflective coating. Our coatings are NSF rated safe for water catchment.
What about interior walls? Wherever we need to cover the metal container wall inside, or where desired, we spot weld thin, hollow metal studs horizontally for hanging your choice of wall materials. Wiring, insulation and plumbing fits perfectly inside the walls with our steel studs. Insulation in the walls is not required on any island, but highly recommended by us. Please note that the bldg dept requires drywall or other specified fire resistant material for wall covering due to fire ratings. Where we build walls such as for bedrooms, bath and kitchen, we use 2x4 steel framing, but we don’t punch holes through the can. The stud on the floor is screwed through the thick wood floor, and the vertical and ceiling studs are welded in place. Our homes have no wood on the inside of any wall, which gives one peace of mind regarding termites. That being said, you should keep your eye out for any mud tunnels laid down by ground termites by looking periodically underneath your structure. Most of our homes have post and pier foundations made of wood, so that foundation and the wood floor of the cans, as well as whatever wood doors etc you choose inside your home is the only wood that you need to monitor. The containers wood floors are generally coated with a material that insects and termites do not like, so that is not a significant worry. Compare this scenario to a home made entirely of wood, with wood inside the walls everywhere that termites could get into without anyone knowing. It is possible to take out the wood floor if you wanted to, but we see no need to. Ceiling insulation goes on top of the containers metal “roof” so no ceiling insulation is within the interior space.This translates to no mold problems in that area. This is a compelling reason to not install exterior siding- seeing your metal walls allows you to catch any rust or punctures before water can cause mold inside your walls, and before rust can spead and create problems.
You can make container homes that do not have a gabled trussed roof. A flat roof is used mostly where people want a slick, contemporary industrial look. The problem with that on Oahu is that you have to create a 5.5 inch airspace in the ceiling, which lowers your ceiling height drastically- 5.5 inches airspace plus the thickness of your insulation. Oahu requires a total of R19 ceiling/roof insulation, which can be accomplished with foam insulation under the roof and some foam or fiberglas insulation in the ceiling just below the containers metal “roof”. This allows you to use thinner insulation on the roof, and thinner insulation in the ceiling space with less air space, giving you that slick modern look, a higher ceiling height inside and complying with the rules. Big Island folks can put ceiling insulation with liitle or no air space because they do not even require ceiling insulation. We definitely recommend it.
What about flooring? The lowest cost option is simply using the plywood floors that come with the cans. They are 1 1/8” marine grade mahogany plywood that can possibly be sanded and finished, depending on the condition of your particular floors. You do need to seal them up with something that locks out moisture and vapors if you want to use them as your actual floor surface. We do not recommend going this way, mahogany stinks. A floor applied on top of the mahogany that is sealed will eliminate the smell if done right. If you insist on using them, the metal trimming around the wood can be sanded and painted. Ceramic tile floors are the best suited with containers. This is due to the thinset adhesive being able to lay down thick to float out the slight level differences between the wood and metal on the container floor. Bamboo or other wood flooring requires floor leveling compound to be applied. We recommend hiring a flooring specialist to do that, it is not easy, and requires a lot of experience. You do not want to create a disaster. It is recommended to create a moisture barrier if laying a floor down via a coating product called MVP or similar. Although a shipping container's metal sub-floor is super strong, rust can cause problems later on, so it is recommended to at least do something to slow it down once you have the containers off ground on your post and pier foundation. We wish this could be avoided, but in all honesty, we have to mention this. New containers would provide a much easier way to deal with this, and might be worth the extra money In the beginning. The black rust proof coating that comes from the factory on new cans is in great condition compared to used cans.
How are windows and doors finished? With windows, vinyl is the lowest cost, they don’t rust and work well in Hawaii. If you want maximim ventilation, you should consider those large glass louver windows with vinyl frames. The let in almost 100% vs sliding vinyl lets in about 50%.We spot weld L-shaped metal around the entire outside window opening, screw the window through the metal wall from the inside. The screws are hidden from sight via the L-shaped metal outside. Having an overhanging eve reduces water getting into your windows obviously, and this plus the natural shade produced are very compelling reasons to have an overhanging roof. Again, we offer thick secure metal coverings as an option to cover and lock down entire window areas made from metal the same thickness as the walls of the can if desired.
Hot water showers? Yes. We recommend on-demand hot water systems powered by gas preferably. You can run cooking on gas also. These systems are thrifty on energy, require no storage tank, and make for easy and clean installation. Not to mention great hot water performance and reasonable cost when you consider everything overall. Initial costs are lower with conventional tank systems, but energy savings and easy, clean installations override that initial cost benefit in our opinion. The best option is solar hot water if you can swing the upfront costs. You can also make your own solar water system if you know what you’re doing.
What is the kitchen like? We are very pleased with our kitchen designs. Lots of countertop space. Hardwood cabinets with no particle board anywhere. Particleboard sucks in every way. Humidity destroys it, the vapors outgassing are nasty smelling and unhealthy, you can’t depend on securing anything to it as screws strip easily, etc. The kitchen in our entry level home is generous & functional. For those of you wanting to build the interior of your home by yourself, you can make your kitchen out of whatever materials you want.
What are the bathrooms like? Generally simple fiberglass shower stalls. We are searching for a black shower stall as an alternative to white. We recommend hot water supplied via on-demand, tankless systems heated via gas, and traditional options are available depending on your situation. Solar hot water is a great option as well if you can swing the initial costs. Tile floors work well here, and you can go composting toilet- flushing or non-flushing, or traditional septic system. Our bathrooms are fairly generous space wise considering the homes overall size. All bathroom walls will be framed walls, using steel studs.
Can I have a laundry room? Yes. How you power that again depends on your choice of energy systems. Traditional electricity, gas, or solar electric PV. We suggest welding a small laundry room on the outside of most of our structures, and also recommend washers and dryers made by Equator. They are the most energy efficient in the world, and can be powered by PV power quite easily. Their new dryer technology offers washing and drying in the same unit, and uses tiny amts of power. It is revolutionary stuff. Equator also makes the worlds most efficient reefers-freezers that can also run on PV power. Yes they cost more, but save you lots with their incredibly low power consumption. The styling is ultra modern, and the design is first class. As time marches forward, more energy efficient appliances are appearing. Be careful to evaluate the actual power consumption, do not be hypnotized by the energy star sticker. Look at the power consumption numbers. With competition, you should be able to get units performing as good as Equator at a lower cost hopefully.
Are these homes green? Absolutely, and how green depends on you and your situation. You are first off recycling used steel shipping cans. From there, the next consideration is power. Going full or partial solar photovoltaic, aka PV is the most significant step towards the green lifestyle. Wind is also a very viable option and can be used together with PV if you have wind. We offer the products and installation to do that. Solar water heating is the next most significant step, but we also really like the on-demand gas heaters due to their great energy savings, reasonable initial cost and clean, simple installation with no storage tank. Solar costs significant money to get installed. You get the credits afterwards, and we obviously give it our thumbs up all the way, but you need to decide if you can swing the upfront costs along with everything else at the same time. You can also heat water on your roof in a black tank and use that for the lowest possible cost. It does require periodic replacement, so we don’t really like that side of it. It is easiest to go with a system that be plumbed properly into your system that does not require much thought or maintenance. Read about equator appliances in the “can I have a laundry room” section directly above. They are green any way you use them- either with PV power or on-grid, they are the world’s most efficient appliances. Being green also means using your gray water to water the landscape and grass. Click here to read about that and useful info regarding alternative septic systems. Don’t forget- being green means shading your home with a long eve, and a roof coated with ceramic coating, lots of ventilation via windows and doors, ventilating skylights for heat to rise out of and natural light to come in. Do not get fanatical, do what you can, and leave yourself the infrastructure to add on later. Shading, ventilation, & insulation are the priorities to do while building, so they are the priority. Finally, believe it or not, if you want to personally be green and help the planet, not eating meat is a very significant and easy step. Animals give off large amts of methane gas, which has a very significant carbon footprint, and it takes ten pounds of grain to produce one pound of meat, and a lot of water. Rainforests are being raped and burned to raise cattle, so if you are really serious about being more green, look into this issue and consider not eating animal flesh.
Affordable Portable Housing
Oahu headquarters- 14 Aulike St. #909, Kailua, HI 96734 808-339-5639. By appointment only.
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