A Nevada purchase agreement is fully executed by both parties. Three days later, both buyer and seller mutually agree to add an addendum specifying that the seller will replace the HVAC system before closing. What is this addendum called and is it binding?

Explanation

A written modification to an existing contract signed by all parties is called an amendment (or addendum). In Nevada, once a purchase agreement is fully executed, any changes require a written amendment signed by all parties to be binding. The original contract remains in force with the new terms incorporated. This HVAC replacement requirement would be enforceable as a contractual obligation of the seller. Nevada agents must use proper amendment forms (typically promulgated by the Nevada Association of Realtors) to document post-execution changes.