Return on sales in the Czech building industry? Does firm size matter?

The presented paper explores the link between firm size and returns on sales (RoS) in Czech building companies. We examined how different business sizes relate to the return on sales, considering staff numbers and the RoS movement over a period. The CRIBIS database of CRIF Company - Czech Credit Bureau provided relevant data from 2016 to 2020, including profitable and active building enterprises. The industry analysis involves an empirical approach using industry structure analysis, return on sales analysis and observing its movement from 2016 to 2020. The industry predominantly encompasses small firms of fewer than 25 employees, exhibiting dramatic variations of the average return on sales over the period. Large companies exceeding 250 employees show complete conformity, yet their numbers are small in the construction sector. The correlation analysis revealed that the business size, i.e., staff numbers, is independent of the return on sales. The submitted work suggests a new size classification according to total assets and sales