In the process of constructing the prototype, a number of things were identified that could reduce the build time and lower the cost of the unit.  Adjustment of material selections, modifications to the brackets that hold the structure together, method of fixing structural members into the brackets and sequence of assembly are some of the areas where improvements could be made.  In addition, a large proportion of the prototype construction time was spent fabricating and preparing components.  The ultimate goal is to provide a complete, lowest-cost, flat-pack kit that could be assembled in the least possible amount of time by the minimum number of people, without having to do things like cutting, drilling, welding, painting and fibre glassing.

Regarding the interior fittings, fixtures and systems, concepts have been produced and will need to be developed, tested and refined.  These include the kitchen, bathroom, rooftop garden, energy, heating, waste treatment and water production.  Some design work has already been carried out on the latter, which is basically a solar-powered air conditioning unit, built to condense water vapour out of the air (I spent ten years working in industrial refrigeration design, so it’s right up my alley!).  The unit should be able to provide between 2 to 4 gallons an hour in a temperate climate, and would be constructed to fit within the space available in the kitchen counter.  A roof-mounted solar array of around 3kW would be used to drive the system.

Compact solutions for furniture will also need to be found, whether off-the-shelf or bespoke, as will solutions for hanging storage upstairs and staircase(s) between lower and upper floors.  Another idea is to have a storage platform fixed to the upper frame construction that will hold bedroom furniture, and will be raised to the level of the upper floor as the house unfolds to allow easy packing and unpacking of the bedrooms. When the house is collapsed for transport, this storage platform would fit into the free area within the kitchen or bathroom.

In terms of evolution of the overall design, it could easily be adapted for smaller scales or different functions.  Initially, a reduction from a hi-cube container format to a standard container format could be envisaged, which would yield a slightly smaller/narrower unit with a slightly lower cost. The design could also be further reduced, say to a unit half the length, perhaps for crisis or humanitarian use.  Making the unit larger by extending the length, though possible, would present certain challenges that may be difficult to overcome.  An easier way to obtain a longer unit would be to link two modules together, either on an articulated trailer or on a static site.

While the envisaged use for the unit at present is to provide a mobile primary dwelling, it could really be repurposed for just about anything: a guest cottage, a holiday retreat, an emergency shelter, an office or workshop space, or a storage unit, to name but a few uses. Furthermore, the design could be used to provide low-cost housing in developing countries, or quickly deployed during humanitarian disasters.  At present, the design is based on using 2-inch rigid insulation material for all roof, and wall panels, with 4-inch insulation on the floor panels.  Initial calculations indicate that this should be sufficient for temperatures just below freezing, but the design would need to be modified for use in low temperature environments by increasing the insulation thickness.