The Rental Housing Act of 1985 covers more than 60 percent of all rental housing in the District. According to this law, there are several ways a landlord can raise an apartment`s rent ceiling ­­ the legal limit that can be charged for that unit. The one most renters will run into is a yearly automatic rental increase based on the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI­W).

Once every 12 months, landlords of properties covered by the law are allowed to increase the rent ceiling by a percentage equal to the CPI­W, which has been running between 1 and 3 percent in the last few years. (Note: the rent ceiling is the legal amount a landlord is allowed to charge on an apartment covered by the law, but not necessarily the amount he will charge.) A landlord can increase the rent any amount he likes so long as it remains under the rent ceiling. Rent can be increased only with 30 days` written notice, and only if at least 180 days have passed since the last increase.