What are NECA labor units?

NECA labor units are standard installation times from the NECA Manual of Labor Units, the estimating reference electrical contractors have used since 1923. Each item has three units, for normal, difficult and very difficult conditions. NECA's 2021–2022 sample page lists 5.00 labor hours per 100 feet of 3/4-inch EMT under normal conditions. The units include normal non-productive labor but leave out supervision.