I've tried to visit this place on a few occasions but they are never open. They seem to close in the early afternoon and on weekends so if you can't get in there in the morning during the week don't bother. Also, I don't remember seeing any hours of operation posted.
I love this place so much that sometimes I'll drive two hours from my home just for the tea and atmosphere Zencha offers. I'm a big fan of asian tea culture and no other tea houses around offer a sense of eastern tea culture in their modern tea house like Zencha. The service is excellent and the owner and staff are very knowledgeable.