Tiny house on wheels: vehicle, building, or both

This is the question that catches people out, because the intuitive answer is wrong. Wheels do not settle it. MBIE's guidance says tiny houses on wheels "will often be vehicles e.g. motor homes but may also meet the definition of a building if they are immovable and occupied by people on a permanent or long-term basis. Each tiny house should be considered based on its own characteristics."

What does the law actually say?

Section 8(1)(b)(iii) of the Building Act 2004 defines a building to include a "vehicle or motor vehicle (including a vehicle or motor vehicle as defined in section 2(1) of the Land Transport Act 1998) that is immovable and is occupied by people on a permanent or long-term basis". The word doing the work is and. Immovable on its own is not enough. Occupied long-term on its own is not enough.

How do you tell if it is immovable?

MBIE gives seven questions and says "all circumstances will need to be taken into account". No single answer decides it.

• Does the design enable it to be moved or relocated with relative ease?
• Are there features common to vehicles, such as suspension, shocks, springs, brakes, brake lights, turn signals and number plates?
• Does it have a warrant of fitness or certificate of fitness, or could it pass one?
• Does it rest on wheels alone, or is it otherwise self-supported, or requiring some other form of stabilisation?
• Is it connected to features that would need to be deconstructed if it was to be moved, such as foundations, walkways or decking?
• Has it been moved in the past, and is the intention to move it in the future?
• Is it connected to on-site services, and how has this been done — water, wastewater, electricity?

Read as a group, these are asking one thing: could this actually be towed away tomorrow, or has it quietly become part of the site? A deck built up against it, a permanent water connection and no tow vehicle in five years point one way, whatever the trailer underneath says.

What counts as occupied on a permanent or long-term basis?

MBIE gives three things to weigh up, and the answers are broader than most people expect.

• Is it used, or intended to be used, for residential purposes and occupied by people? That includes primary places of residence and weekend or holiday homes.
• Is it used, or intended to be used, by people for business activities? If so, it is considered occupied by people.
• Is there no anticipated end date to its occupation? Long-term occupation is something less than permanent, but is contrasted with merely temporary or short-term occupation.

Which way does the flow chart run?

What happens when you connect it to services?

This is the single most common way a tiny house on wheels turns into a building consent problem. MBIE is unambiguous: "If you are planning to connect your tiny house to utility services, such as storm water or foul water, you will need to obtain a building consent." Its table on using a vehicle as accommodation says the same thing twice — connect to on-site utility services such as water or foul water, and a building consent is required.

What about towing it on the road?

If it is a vehicle, it has to be road legal. MBIE: it "needs to have a warrant of fitness (WoF) and, irrespective of having a valid WoF label or not, it needs to be road legal (meaning legally required tyres, suspension, brakes, lights etc. must be fitted and working properly)".

Width is the other constraint. "To be used on the road as a vehicle a tiny house must be within the dimension limit for a standard size vehicle. The standard size is 2.55m wide, if it is wider it must be transported as a load." And a load is a different thing again: "A load is temporarily transported on a trailer, it cannot be permanently fixed to, or part of the trailer."

Over 2.55 m, MBIE lists what an over-dimension move involves: travel time restrictions depending on the size of the load, a route survey to make sure it will not get stuck, pilot vehicles, and possibly an over-dimension load transport company to relocate it. Price that in before you choose a width.