Details Calculation Of BOCW Cess

Dear All,
Please let me know the details calculation of BOCW Cess .
I have little confusion as follows:
Total Cost / Value Rs 100
Out of the same :
Labour Component is Rs 20
Deatils Engg / Design is Rs 20
Supply project materials Rs .40
Supply Construction Materilas Rs 15
Profit is Rs 5
Now the cess will be calculate on which , is it only on Labour Component or total contract value including profit .
As I know service tax is not under the cess as per BOCW ACT 1996
Looking forward your help.
Thanks Subroto

Dear Subroto,
The cess will be on cost of construction and cost of construction shall include all expenditure except cost of land and any compensation paid of or payable to a worker or his kin under the Workmen's Compensation Act, 1923.

But till I am in gel, 'cost of construction and cost of construction shall include all expenditure' that means the all supply and other cost will be treat as cost of construction?
Is there any notification?
Say there is three separate work order one for supply of Project Materials which to be directly install, another for commissioning and third for construction , then can we consider the above three WO as cost of construction. Or we will only consider only construction part.
kindly enlighten.
Thanks Subroto