The experienced centre-half is more than 500 appearances into his career but at his Terriers unveiling said the Championship club appealed to him partly because he felt head coach Carlos Corberan could take his career on to another level.
Lees made 274 appearances for Wednesday across seven years at S6.
“Where I am in my career, I’m really eager to keep improving,” he said. “I’ve seen it first-hand now, but I liked what was said to me about the culture here and the way that the Head Coach improves the players.
“There are a lot of case studies of that, and I’ve seen it last season when we played against Town in the first half of the season. You could see the patterns of play and, as a defender, it was really hard given the movement of the players.
“I’ve seen a lot of players really improve when they go into a good environment with a good head coach, and I want a bit of that.”
Lees also revealed a key role another former Owl played in convincing him to make the switch to West Yorkshire
“I gave Jordan (Rhodes) a ring when things looked like they might be happening and asked his opinion. He spoke really well of the dressing room, the spirit and all the staff, and that’s been true today when I’ve come in.
“The staff have been amazing, the dressing room has been really good and it’s a good setup.”