From the miniHome site:

In order to provide more living space in the miniHome SOLO, we have been asked by many of you to allow for additions. The best way to do this was to work with the exisiting floor levels and roof lines of the SOLO, and find a way to ‘marry’ the two pieces to give the best interior spaces.

The result: the miniHome DUO SE:

The miniHome DUO is a modified miniHome SOLO with more! Two units ship separately to your site, and then combine at the ‘marriage wall’ - a simple operation that makes the DUO a permanent home1. Both units are classed as trailers (CSA Z220- RV), are on wheels and a steel chassis and both feature detachable hitches. The units can be towed to any site and requires no foundation or infrastructure hook-ups. Designed and built in Canada for year round living, the DUO’s robust construction is super-insulated, making it quick and easy to heat and cool. The DUO also features an optional woodstove, for colder climates.

For the environmentally minded:

The DUO has numerous environmental advantages over conventional housing. A smaller building uses less resources and energy to build, and ultimately much less energy to operate and maintain. The modular design also keeps construction waste, shipping costs and energy to a minimum.

Jetson Green wants one:

Really, anything is possible with this little treasure home. Small. Stylish. Green. Affordable.