In implementing the grid, existing buildings were allowed to remain where they were if at all possible, but if removal was necessary the owners would receive compensation from the city, although appeal was available to a special panel appointed by the state's highest court. (See "Opening" and "regulating" the streets below) In 2011, it was estimated that 39% of the buildings north of Houston Street which were standing in 1811 (721 out of 1,825) had to be moved. On the other hand, if the plan improved the accessibility of a property, the city was authorized to levy an assessment on the owner for the improvement, a method previously used by the city after building public amenities, such as wells.