The application, opposed by 32 of 33 submitters, was declined by independent commissioner Rob van Voorthuysen after a hearing in August.
Cooke was one of the submitters and told the hearing the building was "priceless and irreplaceable" and a core part of the Edwardian gateway to the city centre which had a cluster of heritage buildings.
"[It's] a precedent, I believe, as a community we cannot condone."
Following the release of the application decision, the property was advertised again for sale and was sold privately.
Smith told the Whanganui Chronicle it was business as usual for the building and the current tenants would remain at this stage.
"I haven't firmly decided what my plans are," Smith said.
"I'm going to not demolish it. Over time I'm sure I will address some of the issues that relate to the building. It's a fantastic building I think. We will be doing our best to make sure it's preserved.
"If all heritage buildings in Whanganui were knocked down, Whanganui would be a shadow of its former self. I can't afford to buy them all but I could afford to buy that one."