Interior designers make indoor spaces functional, safe, and beautiful by determining space requirements and selecting essential and decorative items, such as colors, lighting, and materials. They must be able to draw, read, and edit blueprints. They also must be aware of building codes, inspection regulations, and other considerations, such as accessibility standards.Interior designers work closely with architects, civil engineers, mechanical engineers, and construction laborers and helpers to determine how interior spaces will function, look, and be furnished. Interior designers read blueprints and must be aware of building codes and inspection regulations.