FIDIC 2017 – How Strong is Your Knowledge?

Dear,
Clause 12.3 can be only seen on case by case basis. Formaly to get the new rate there are several exactly presented assumptions which must be fullfilled.
On the other sude even a smaller quantity change of an item could have impact on the other items and work in general. Consequently it could result with additional costs and time for conpletion extension.
It is in any case up to the Contractor to study carefully and permanently technical specifications, drawings and all other relevant Contract documents from the pre tender, tender and post tender stages, to be able to act timely with appropriate notice(s) asking for explanations, clarifications and finally if finds himself entitled, for a completely new rate, or a rate based on the similar already existing item(s).
Any change in quantity in my humble opinion could result with variation, but even the higher changes could be also solved through the re-measurement process,of corse if it is about RED BOOK 1999 or 2017.
To conclude from my experience. Contractor realy must collect sufficient proves, evidences, records and all other documents enabling him to substantiate entitlement for any of its rights. I also suggest always to have prepared detailed price breakdown i.e. unit price analysis for each single, particularly most important BoQ items, having regard to all available but also in previous projects experienced data.
With a hope to be helpful with this most probably late answer I remain
Sincerly Yours
Sead Jamak