Whether levy or not service tax?

Our client is a contractor in construction of flats and bill charged on the basis of carpet area i. e. 200per square feet. Materials provided by contractee and our client work only on site is basic structure prepare and some work like walls structure and tiles fitting. Our client work as pure labour contact. Our client working as proprietor. Please suggest whether our client charge service tax or not and if charge what process of charge and paid service tax.