sidewalk superintendent

noun, Informal.
1.
a bystander who watches the building, demolition, repair, or other work being done at a construction site.
Origin
1945-50
Slang definitions & phrases for sidewalk superintendent

sidewalk superintendent

noun phrase
  1. A person who watches excavation or other construction work, usually through a hole in the surrounding fence
  2. Any amateur critic or observer (1930s+)