He found that the amount of space and the positioning of barriers affected people's comfort. He also found that fencing yards and giving ground-level renters control of them resulted in decreased vandalism. Other studies have found that lighting and landscaping can aid in reducing crime by improving visibility and, thus, increasing the risk of offender detection. Security professionals should encourage architects to allow input on environmental design early in the planning process. When making suggestions, security professionals should speak to the planner first, inform superiors of their strategy and get support from them, attend planning conferences, and point out environmental design solutions that may reduce problems for law enforcement personnel. Environmental design provides a means for lessening the opportunities for crime and increasing offenders' perceived risk.