Historic zoning offers an incentive for owners to protect treasured property.

The Heritage Society of Austin has recommended the city ban agents who charge a contingency fee for acquiring historic status for a home or business. The society cited a large increase in such filings last year.

"Some sort of private agents were coming in and making more of a business out of land-marking properties. That's certainly affected the program," Jacqui Schraad, of the Heritage Society of Austin, said.

Schraad said contingency fees result in a disproportionate number of filings in high-end neighborhoods.

"The concern is, if somebody is doing something on a contingency fee, they're deliberately seeking out really high-end properties to landmark them to personally profit from that, and that's not the spirit of the land-marking program," she said.

Next month, the Historic Landmark Commission will give city council short-term recommendations on limiting the number of historic zoning changes allowed.