JCT DBSub/C 2016 - quantity errors/changes

Clause 5.1 of JCT DBSub/C 2016 states that, where the Remeasurement Basis applies, the modification of the quantity of the Sub-Contract Works is not a Variation. Clause 2.9.3 seems to contradict this by stating that any error in quantity in the Bills of Quantities is to be treated as Variation. Please explain.

Clause 2.9.1 is concerned with defined Provisional Sums and the correction of the same where there is inadequate information as is required under the Measurement Rules. This is not related to a remeasure but specific defined Provisional Sums.

Clause 2.9.2 is concerned with inadequacies in the Contractor’s Requirements (being that part of the Sub-Contract Works that the Sub-Contractor) is to design. Again this is not related to a remeasure but the design portions of the Sub-Contract Works.

Clause 2.9.3 states that these specific items under 2.9.1 and 2.9.2 are to be treated as Variations and that is limited to defined Provisional Sum items and design elements. Clause 2.9.3 is therefore specific to the 2 items in 2.9.1 and 2.9.2.

Where the Sub-Contract Works are to be measured on a remeasurement basis then the correction of the quantities is dealt with as the Sub-Contract Works are remeasured and not as Variations. Clause 5.1 therefore makes it clear that corrections in quantities are not Variations as they will be picked up in the remeasure, subject of course to the specific items in 2.9.1 and 2.9.2.

Thanks for your response.

However, my reading of cl 2.9.1 is that it is not exclusive to Provisional Sums but rather also applies to any quantity error in the BoQ (“If in any Bills of Quantities…there is…any error in quantity…the error shall be corrected…[which correction] shall be treated as a Variation”).

If this is the case, then correction of quantities per cl 2.9 is a Variation whereas cl 5.1 suggests that a modification of the quantity of the Sub-Contract Works is not a Variation.