A property is sold with a building inspection condition. The inspection reveals minor issues that the purchaser considers acceptable. What must happen for the sale to proceed?

This question tests understanding of conditional sale and purchase agreements under New Zealand property law. Building inspection conditions are among the most common conditions in residential property transactions, protecting purchasers from unknown defects. The key principle is that all conditions must be formally satisfied or waived in writing by the benefiting party, regardless of the condition's outcome. This requirement ensures legal certainty and prevents disputes about whether conditions have been met. The written notice requirement protects both parties by creating a clear paper trail and preventing misunderstandings. Even if inspection results are favorable, the purchaser cannot simply proceed without formal written confirmation. This principle applies to all conditions in sale and purchase agreements, not just building inspections, and reflects the importance of clear documentation in property transactions under the Property Law Act and standard TLANZ/REINZ agreement forms.