The Truth About the “Third Party Wall Agreement”: A Homeowner’s Guide A “third party wall agreement” isn’t a real legal term under the Party Wall etc. Act 1996. It usually refers to a Party Wall Award, the official document allowing work to proceed. The confusion comes from the Third Surveyor, who only steps in if surveyors disagree. https://www.partywallslimited.com/blog/the-truth-about-the-third-party-wall-agreement-a-homeowners-guide