The Star revealed last month the Arminia Bielefeld defender had held talks with the Owls regarding a move to Hillsborough this summer.
And speaking to newspaper Neue Westfälische, Börner himself says he is currently preparing to move his family to England next week.
The 28-year-old had initially informed Bielefeld he would be remaining with the club but said the opportunity to play in England was too good to turn down.
"I definitely have not made it easy and can understand the trouble," he said.
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"But it has always been a childhood dream of mine to play in England."
"Suddenly this economically interesting offer came in," he added.
"I flew over, talked to those responsible, completed the medical check-up and signed it."
In the report, Börner revealed he would be subletting his home in Germany and plans to return with his family once his daughter reaches school age.
He is expected to link up with the Wednesday squad on the first day of pre-season training.
The Owls are also understood to have secured a deal for another target, Brentford winger Moses Odubajo.