The optometrists would move to 394 Cameron Rd between Fifth and Sixth Avenues on Tuesday. The business would also change its name to Tauranga Eye Care by Langford Callard.
Mr Langford said there were many emotions about moving.
"We have known for a long time that the building would be demolished. We have kept a good relationship with Farmers.
"We would have been happy to stay if the building was presentable, but the whole building is looking a bit tired. We have enjoyed our time here."
Business partner Mike Callard said he had mixed feelings about moving out of the CBD.
"It is a little bit sad," he said. "It could take four or five years until the redevelopment is complete.
"I think they will have some challenges, but I think this will be fabulous for the CBD once the transition period is over. But the plans are very positive. I think the council will fight to keep the Farmers building here."
Subway was also on the Farmers-owned site.
Manager Jennifer Gilder said the food outlet would move to a new site when the building was demolished.
"We are hoping to be able to come back to the new building when it is redeveloped."
Priority One projects manager Annie Hill said the CBD was now the place to be.
''Apart from Farmers, which is moving out so they can redevelop and significantly invest in the site before moving back in, we are not aware of other businesses of scale that are moving out of the CBD.
''There was a trend a few years ago because of the shortage of high-quality office accommodation and earthquake strengthening issues with buildings, but we have seen that turn around over the last 18 months and the city centre is now quite a sought-after place to be based. Both the Ignition and Basestation co-working spaces are full up, in fact Basestation is expanding upstairs.
''We also have other businesses such as Harrison Grierson, who moved out a few years ago and are now back in the city centre.''
Farmers Trading Company bought the building it is in for just over $13 million in 2015. The Bay of Plenty Times Weekend reported in July 2015 that the current store was not big enough to display all of Farmers' stock and the company had indicated it wanted to stay on the site in a new two-level, regular-shaped building with 3500sq m on each floor.
Farmers declined to comment for this article.