Ulhasnagar model of regularising illegal structures has not yielded any results and the same yardstick could not be applied to other cities as each one has different problems and issues,’ Chavan said while replying to a debate on illegal structures in Pimpri-Chinchwad. ‘In Ulhasnagar, out of the 6,623 illegal structures, not even 100 have been cleared for regularisation. Structural stability is a must for regularising,’ he said.