New York Laws
Part 2 - Formation and Construction of Lease Contract
2-A-208 - Modification, Rescission and Waiver.

(1) An agreement modifying a lease contract needs no consideration to
be binding.
(2) A signed lease agreement that excludes modification or rescission
except by a signed writing may not be otherwise modified or rescinded,
but, except as between merchants, such a requirement on a form supplied
by a merchant must be separately signed by the other party.
(3) Although an attempt at modification or rescission does not satisfy
the requirements of subsection (2), it may operate as a waiver.
(4) A party who has made a waiver affecting an executory portion of a
lease contract may retract the waiver by reasonable notification
received by the other party that strict performance will be required of
any term waived, unless the retraction would be unjust in view of a
material change of position in reliance on the waiver.

Structure New York Laws