The Institute of Professional Engineers has expelled the designer of Stadium Southland, which collapsed in a snow storm in 2010.
A disciplinary panel of IPENZ found Anthony Stanley Major was incompetent, negligent and potentially caused loss of life.
The Invercargill stadium was built in 1999. The roof sagged in September in a snow storm.
The disciplinary hearing took place in December 2013 and Mr Major took up his right to appeal, delaying the final decision until last Wednesday.
Mr Major is required to pay all costs relating to the disciplinary process.
The collapse prompted a Department of Building and Housing probe by Dr Clark Hyland.
He concluded the degree of non compliance was so significant it warranted involvement of the Police.
He found during construction the thickness of some trusses was changed from 9mm to 6mm.
There was also substandard steel fabrication and welding.
IPENZ chief executive Andrew Cleland says the expulsion is the ultimate sanction and reflects the seriousness of the offending.