## Facts

- Oppenheimer & Co., Inc. sought to sublease its 33rd-floor office space at One New York Plaza after relocating to the World Financial Center.
- Oppenheim, Appel, Dixon & Co. (OAD), an existing tenant in the building, sought additional space.
- In December 1986, Oppenheimer and OAD executed a conditional letter agreement with a proposed sublease attached.
- The agreement stated there would be no sublease “unless and until” Oppenheimer delivered the prime landlord’s written consent to specified “tenant work” by a fixed deadline (February 25, 1987).
- The agreement further provided that if the condition was not satisfied, the letter agreement and sublease would be “null and void” and neither party would have rights or obligations to the other.
- On the deadline, Oppenheimer’s counsel orally informed OAD’s counsel that the landlord had consented, but Oppenheimer did not deliver written consent by that date.
- Written consent was delivered weeks later, on March 20, 1987.
- OAD declared the agreement invalid the day after the deadline and refused to proceed.
- Oppenheimer sued for breach, arguing the condition was satisfied by substantial performance and that OAD was barred by waiver or estoppel.

## Issues

1. Whether substantial performance can excuse nonoccurrence of an express condition precedent requiring delivery of the landlord’s written consent by a specified date.
2. Whether failure to satisfy that condition meant no sublease came into existence, eliminating contractual liability for breach.

## Decision

- The Court of Appeals reversed the Appellate Division and reinstated judgment for OAD.
- The court held substantial performance does not excuse failure to satisfy an express condition precedent stated in unmistakable conditional language.
- Because Oppenheimer did not deliver the landlord’s written consent by the deadline, the condition did not occur and no enforceable sublease arose.
- The court found no equitable basis to relax strict compliance because enforcement did not create a disproportionate forfeiture.

## Legal Principles

- Express conditions precedent are enforced according to their terms and generally require strict compliance.
- Substantial performance may mitigate minor defects in performance of promises, but it does not substitute for the occurrence of an express condition precedent to a duty or to contract formation.
- Clear conditional drafting (e.g., “unless and until,” fixed deadlines, and “null and void” language) signals intent that obligations arise only upon the condition’s occurrence.
- Equitable relief from strict compliance may be available where nonoccurrence would cause disproportionate forfeiture, but not where the party has not incurred losses that equity treats as forfeiture.
- Waiver or estoppel may affect enforcement of a condition, but substantial performance alone cannot transform nonoccurrence of an express condition into satisfaction.

## Conclusion

The court held that the parties’ sublease never became effective because the contract made timely delivery of the landlord’s written consent an express condition precedent, and substantial performance could not excuse missing that condition absent a forfeiture-based equitable rationale.


Oppenheimer & Co. v. Oppenheim, Appel, Dixon & Co., 86 N.Y.2d 685 (1995)