A due diligence access letter agreement allowing a purchaser to enter onto property owned by a seller to conduct environmental due diligence for the possible acquisition of the property. This Standard Document identifies each party's rights and liabilities when the purchaser enters onto and conducts an environmental investigation of property it does not own. This Standard Document has integrated notes with important explanations and drafting and negotiating tips for both sellers and purchasers. While real estate access agreements are generally covered by state law, this jurisdictionally neutral template is useful and relevant in every state.