We examine the effects of an airport expansion on the prices of houses and apartments located under the planned flight paths. We focus on the role of expectations of aircraft noise during the expansion of Berlin-Brandenburg International Airport. The publication of the flight paths can be seen as an exogenous event. It provides local residents and potential home buyers with reliable information in a situation that is characterized by uncertainty. The flight paths greatly influence the expectation of the noise level. We find that property listing prices were reduced substantially in the affected areas after the flight paths were published. The loss of value of the affected properties was found to be 9.6 % on average within a slant distance of 3 km from a planned flight path. If the flight altitude is below 1,000 m, the discount is between 11.8 and 12.8 %, whereas for higher flight altitudes, the average decline in prices is estimated to be 8.3 %.