How do you determine the construction costs of your project?

Using a very good estimate program, QS, planning, project control manager, EVM, Scoop and schedule. 

Through quantities and specifications schedules, prices and calculated

Construction Cost is sum of capital cost+operational & maintenance cost.

Capital Cost includes land acquisition,planning & study,design(architectural as well as engineering),Filed supervision,Construction materials,Manpower,machinery,Inspection and testing.

Operational & Maintenance Cost includes operation staff,rent if applicable,periodic renovation,maintenance

Many thanks : 

1/ quantities ( cement , steel , wood  ) .

2/ how many workers for each specialization .

3/time .

 after  i can make costs  project .

not me because am just working in site but goverment do that when they  are put table quantities