In the standard Monopoly board game, one house on a red property costs $150.
The red properties are Kentucky Avenue, Indiana Avenue, and Illinois Avenue. Each uses the same building cost printed on its title deed: $150 per house. Before building, a player must own every property in the red color group, and houses must be distributed evenly across that group.
The cost applies to houses, not hotels. A hotel is bought after four houses have been placed on a property, subject to the group’s building rules. Red properties are in the higher-priced half of the board and generally produce stronger rents than the orange, pink, or light-blue groups.
Edition differences can change street names or prices, especially in localized and themed versions. The $150 figure belongs to the classic American standard board and should not be generalized to every Monopoly edition.