Bills of Quantities vs Schedule of Quantities and Rates

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19 Aug 2019: First created

 

Item

Description

Bills of Quantities

Schedule of Quantities and Rate

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