TRL did not comply and the company was taken to court, but the charge was withdrawn because the section had been sold to another party.
The land reverted to TRL and the council said the notice to fix remained in place.
The MBIE determination said the units were vehicles "both within the natural meaning of that term, and as defined by the land Transport Act 1998".
"The Authority [CHB Council] has weight on the fact that the units were delivered to the Applicant's property on the back of a truck and lifted on to site. However, this does not mean that the units are not capable of being towed. Both have been designed and built to be towed, with tow bars and associated fittings", the determination said.
TRL shareholder Richard Cuthbert, whose wife Jackie Gibbes is sole director of the company, said the council had conspired to cover up mistakes over whether or not the land had sewage connections and the truth was only revealed after an Official Information Act request.
"You can't get a title without sewage," Mr Cuthbert said.
"We found a year later that they wanted us to put in a big sewage system from one end of the boundary to the other - two manholes. Everyone would have to pay for sewage.
"They already knew it was at the boundary - so the whole thing is they were caught out."
Council chief executive John Freeman said Mr Cuthbert had been told by the council that it was not 100 per cent sure if the sections had sewage.
"The drawings he was shown said there was sewage to the boundaries," he said. "Later information showed that sewage may not have got to each boundary, so we got the surveyor up there to find if each of the sewage connections went to the sections."
Mr Freeman said the notice to fix was first served on the wrong party "in the belief they were the right party".
"Mr Cuthbert pointed out that the other people were the owners because he had a sale and purchase agreement in place, so therefore we changed it.
He said the council had offered to provide a facilitator - an experienced surveyor - but the offer had not been accepted.
"Their development is a good set-up. We like the idea of being able to provide small lots to lifestyle people with mobile caravans or buses.
"If he wants to be able to sell these sections off to these people who like tripping around, from our perspective he can subdivide all he wants so long as it meets all of the statutory requirements."
The MBIE determination was no surprise, he said.
"If they said they were buildings then they would have a problem nationally - there are hundreds of caravans up around the place."
Mr Cuthbert said the sewage and fixing issue had caused sale contracts to fall over and he had incurred substantial legal costs.
"I know it sounds crazy but this has cost us $1 million. It has been dragging on for three years and members of the Motor Caravan Association won't touch us with a barge pole."