Neighbors to the property in Addington Road heard loud meowing coming from underneath the floorboards and contacted the RSPCA to investigate the noise.
A trap was set and a young tortoiseshell cat - whose name is now Tammy - was brought out to safety.
But when builders at the property later saw evidence of a second cat in the property RSPCA inspector Deborah Pert returned to the property and rescued ginger cat, Noel, from the floor cavity also.
The tortoiseshell, now named Tammy, weighed just 2.18kgs when she was brought in for a a check-up.
The ginger, Noel, was also emaciated and was only 2.82kgs when he was rescued - which is just over half the weight he should have been.
Both cats are now being taken care of by staff at the RSPCA Isle of Thanet branch.
Facebook: RSPCA-Isle of Thanet Branch, for more information.
Photo credit: RSPCA