The CESMM requires that the principal components of the works with their approximate estimated quantities shall be given solely to assist tenderers in making a rapid assessment of the general scale and character of the proposed works prior to the examination of the remainder of the bill of quantities. This list is to precede the preamble to the bill of quantities. It is difficult to understand how this requirement could be of any real value to a serious tenderer.
It would in any case be a subjective selection by the engineer of the principal components. It is the tenderers responsibility to select those components that are most significant to him in terms of cost, quantity or difficulty. The early part of the specification should describe the nature, magnitude and output or size, etc. of the principal components of the works so that the extent of the works required is defined and readily appreciated. This is also useful if the cost of the contract is to be of value for cost analysis purposes in the future.