In most building demolitions, the building materials are destroyed and sent to landfills. City officials in Portland, Oregon, wanted to reduce this waste. The officials passed a law requiring demolition companies to deconstruct some buildings instead. Deconstruction involves carefully taking buildings apart piece by piece. Damage to the materials is avoided so that they can be reused in new constructions. A 2019 study found that 27 percent of materials from deconstructions in Portland were able to be reused. The remaining materials were processed for recycling instead of going to a landfill.