Maryland Code, Land Use § 7-304

(a) Except as provided in subsection (b) of this section, the local laws, rules, regulations, and policies governing the use, density, or intensity of the real property subject to an agreement shall be the local laws, rules, regulations, and policies in force at the time the parties execute the agreement.

(b) If the local jurisdiction determines that compliance with local laws, rules, regulations, and policies enacted or adopted after the effective date of an agreement is essential to ensure the public health, safety, or welfare, an agreement may not prevent a local government from requiring a person to comply with those local laws, rules, regulations, and policies.