In New York, elbowing aside others to make money in real estate is as old as the founding of the city itself.

And for every rental building that has been converted to a co-op or condominium over the years, there have been tenants who have felt the sharp jab.

This time around, with apartment sales on the upswing and the number of rent-regulated tenants on the decline, many of the buildings that developers are converting from rental to condo are large and located in areas that are pricey and desirable. And unlike the 1980s, when scores of buildings were converted to co-ops, the fabulous insider deal no longer exists.

But some things remain constant. Those who insist on hanging on to their rental apartments can expect a noisy, dusty mess. “This is one of the hairiest times for renters that I’ve seen in my career,” said Kevin R. McConnell, a real estate lawyer who has focused on tenants’ rights since the 1980s. “There’s tremendous upheaval in the market.”