Barrier-free builing modification consists of modifying buildings or facilities so that they can be used by the physically disadvantaged or disabled. An example would be installing a ramp for wheelchairs alongside or in place of some steps. The idea of barrier free modification has largely been superseded by the concept of universal design, which seeks to design things from the outset to support easy access. This latter approach usually leads to lower total cost. However, with pre-existing structures, barrier free may be the most appropriate or only valid approach.