—Judgment, Supreme Court, New York County (Jane Solomon, J.), entered July 6, 1994, which, insofar as appealed from, dismissed the plaintiff’s complaint, unanimously affirmed, without costs.
Plaintiff waived its claims against the City for extra and additional work allegedly performed by failing to comply strictly with the notice and documentation provisions in Articles 27 and 28 of the parties’ contract. These provisions required the contractor to notify the Commissioner promptly, in writing, that the work directed to be done was extra work and request a final determination from the Commissioner, and also required contemporaneous written detailed documentation of the alleged extra or disputed work performed (Huff Enters. v Triborough Bridge & Tunnel Auth., 191 AD2d 314, Iv denied 82 NY2d 655; Smith Elec. Contrs. v City of New York, 181 AD2d 542).
Plaintiff is not entitled to recover its actual costs of rock excavation on the grounds that the actual quantities removed exceeded the Engineer’s estimate. The exculpatory clauses in the parties’ contract, intended to insulate the City from liability, expressly warned prospective bidders that the Engineer’s estimates of unit items of work to be performed were merely an approximation and that the contractor could make no claim for damages when the actual work required under *245the contract varied from the Engineer’s estimate (Kalisch-Jarcho, Inc. v City of New York, 58 NY2d 377; Conduit & Found. Corp. v State of New York, 52 NY2d 1064; Buckley & Co. v City of New York, 121 AD2d 933). Concur — Sullivan, J. P., Rosenberger, Wallach, Ross and Asch, JJ.