An Auckland man says he was shocked to discover his neighbours could remove half of the building he lives in without having to tell him.
Muhannad Al-Wahb owns one half of a former state duplex in Remuera and said he first heard of his neighbour's plans when they came to him with an approved building consent at the weekend.
They plan to knock down their half to build a free-standing home on their section.
Auckland Council deemed the effects on Mr Al-Wahb to be "less than minor" so the neighbours did not have to notify him of their plans.
If he had been told he might have been able to work with the neighbours to find a solution, he said.
"The whole thing has been done in secrecy and I cannot understand how the neighbour can do this."
Auckland architect Pip Cheshire said he had never heard of such a case and was astounded the council considered the effects on Mr Al-Wahb to be minor.
"The big issue is whether this guy needs to be pushed into this position without having any say in it whatsoever. You would rather think he might have been party to some kind of conversation with the neighbour and council greatly earlier than it appears he has been."
A brick wall which parts the house in two will remain and the council said it will keep Mr Al-Wahb's side of the house weather-tight, but Mr Al-Wahb has concerns about that.
He had done some research of similar moves overseas and said problems eventually arose in the properties.
The council's building inspections manager, Jeff Farensohn, maintained the effects of the demolition would be "less than minor" and would be done under close watch from inspectors.
Mr Al-Wahb's neighbours could not be reached for comment.