Bills of Quantities vs Schedule of Quantities and Rates

1.

Provided by

Employer or his consultants usually the QS

Tenderers

2.

Production time implication

• Done before issuing tender documents
• Long time before issue

• Done during tendering
• Longer time for tendering

3.

Cost of tendering

• Low to tenderers
• Employer bears cost of production of one set only

• High to tenderers
• All tenderers bear their own costs of production with no guarantee of winning the contract
• May pass on to subcontract tenderers to measure

4.

Quality check

• Production overlapping design time
• Relatively longer time available
• Greater chance to do quality check
• Greater chance to improve drawings and specifications when problems are discovered during BQ production

• Relatively shorter time available
• Approximation or short-cuts have to be adopted
• Less chance to do quality check
• Less chance to improve drawings and specifications when problems are discovered during tendering

5.

Measurement rules

According to the Standard Method of Measurement

• Not necessarily according to the Standard Method of Measurement
• Based on common or self-explanatory practice
• Possible to simplify measurement
• More flexible to suit sub-contractors’ pricing methods

6.

Risks of errors in the quantities and descriptions

• Employer’s risks
• Contract Sum to be adjusted for errors
• Deduct over-measurement
• Add back under-measurement
• All the above unless the BQ are declared to be for reference only at the risks of the Contractor

• Contractor’s risks
• Contract Sum not to be adjusted for errors
• Enjoy over-measurement
• Suffer under-measurement
• May try to recover the loss through variations and claims

7.

Risks of errors in the rates

• Contractor’s risks
• Contract Sum not to be adjusted

• Same

8.

Competition

• Compete prices based on the same set of quantities

• Compete prices based on own set of quantities which may be different from other tenders

9.

Comparison of tender prices

• Easier
• Comparing unit rates only

• More difficult
• Comparing unit rates and differing quantities described or grouped differently

10.

Manipulation of price distribution

• More difficult

• Easier due to the possibility of manipulating the quantities

11.

Payment basis

• Easy to use

• Same

12.

Rates for valuation of variations

• Available
• Item coverage certain because of compliance with the Standard Method of Measurement

• Available but lack of compliance with the Standard Method of Measurement may cause argument as to item coverage

13.

Cost analysis for future use

• More reliable and balanced

• May not be so reliable if the grouping or quantities of items are incorrect