Subcontractor has been requested for revised rates for the remaining works due to acceleration of programme (and increased work volume),
To date 30% of measurable contracted works are completed in 7 months due to lack of access areas provided by Contractor ,
There is a 12 month contract timeline in total,
What percentage rate increase would suffice ?
You have to assess acceleration on its own merits. You need to consider the extra cost it will now cost you to complete the works by the earlier proposed Completion Date and any extra risk that brings. It should be pointed out that Acceleration first assumes you have assessed the entitlement to move out the Completion Date with implemented compensation event(s) and the cost that goes with that, before separately agreeing an acceleration quote under clause 36 to bring it back. Acceleration hast to be by agreement i.e. Contractor can not assess acceleration quote themselves.
Speeding up to maintain a date that has not moved is not “acceleration” under the contract so be careful!
Programme is going to be key in all of this - showing where you were, and what it now means to justify associated costs.