If construction output is stated in terms of functional units, the labor productivity will be related with units of product per labor hour, for example cubic yards of concrete placed per hour or miles of highway paved per hour.
On the contrary if it is expressed with constant dollars, the labor productivity is recognized with value of construction (in constant dollars) per labor hour to which factors for waste, overhead, and profit are added to capitulate the unit cost in dollars. A labor dollar per unit of work (ex: $20 per cubic yard for grade beams or $30 per cubic yard for walls) will only be relevant if the cost history supports the data being used.
Now-a-days computer aided design software are available for perfect labor estimating. These softwares are applied for collecting and controlling all labor records, analyzing labor costs with projects and activities for inclusion in project-based cost analysis and reporting. In order to get a perfect estimation of the complete construction costs, just add the labor estimating cost and other contingency expenses.