By Karen Gadbois, The Lens staff writer A plumber with headquarters on Broad Street did his best to follow the rules when he filed an application to demolish a building in a historic area – except that it’s not his property. The fiancée of the owner was at a recent hearing of the Historic District Landmarks Commission, and she said she’s living there and that neither she nor the owner want it torn down. The two-story commercial brick structure is at 1206 N. Broad St.