This term is used interchangeably for different kinds of units, all sharing a small scale <400 sqft. They may be built to be portable, often on a flatbed trailer, and as such are similar to an RV (see above). Under Sunshine Coast Regional District (SCRD) bylaws, these are the same as trailers or RVs and do not meet the requirements of a dwelling (or cabin).
Alternatively, if constructed under an approved Building Permit in compliance with the BC Building Code (on a permanent foundation) connected to an approved septic field, they can serve as permanent or seasonal dwellings.
Note: as SCRD Zoning Bylaws sets no minimum dwelling area, one can apply to build a house <400 sqft BUT the same submission and permit requirements apply as for a larger home, including HPO.