Ask Real Estate is a weekly online column that answers questions from across the New York region. Submit yours to realestateqa@nytimes.com.

Fined for Using Airbnb

I own a unit in a condominium. Last year, while I was on a road trip, I rented out my apartment on Airbnb.com. After I returned, the condo board levied a $1,000 fine against me. No call, no email, just $1,000 added to my monthly maintenance bill. The management company told me that, according to the bylaws, it was against the rules to rent out my apartment for less than 30 days. Shouldn’t management provide some sort of proof — like the dates involved? And, can it assess such a large fine without warning?

Williamsburg, Brooklyn

With housing costs high, turning your apartment into a cash cow a few weeks a year can be irresistible. Who wouldn’t jump at the chance at such easy money? But, as you have learned, this is also an effective way to alienate neighbors and building management.

Renting out an apartment for less than 30 days is against state law in most cases, and certainly in this one. The New York State Multiple Dwelling Law prohibits apartment rentals of less than 30 days unless a permanent occupant of the apartment is present. Building managers, boards and many residents bristle at the idea of short-term rentals, as an influx of transients poses a safety risk and diminishes the homelike quality of a building.