About this Website

• Data
• Use of GRI guidelines
• Sustainability website content
• How data in this report were verified

Data

Except where noted, this report covers all operations of Weyerhaeuser during calendar year 2011. Financial results are for fiscal 2011.

Use of GRI guidelines

Weyerhaeuser has published an annual environmental performance report since 1993 and a citizenship report since 2001. In 2002, we combined these reports into this sustainability report and began following guidelines recommended by the Global Reporting Initiative. In 2004, we issued our first report "in accordance" with the guidelines. In 2005, we had our "in accordance" report checked by the GRI. This is our sixth report produced using the G3 guidelines to an application level of "A."

The codes (e.g., EN 10, HR 5) shown in the GRI Index refer to specific GRI indicators. For more information about GRI and its indicators, please visit www.globalreporting.org.

Sustainability website content

In 2008, we moved from a printed report to an online reporting format using this website. We believe this format will make our information more accessible to stakeholders and facilitate transparency in the company’s disclosure of relevant sustainability information. We welcome feedback on our report via this form and seek to integrate feedback into our annual process.

Our process for determining report content includes:

• Identifying key audiences for the report, including customers, investors, current and potential employees, and other stakeholders.
• Determining the information needs of our audiences based on our internal tracking of stakeholder inquiries, broader sustainability trends, and feedback from key users of the report.
• Comparing these content needs with the Global Reporting Initiative indicators and prioritizing topics within the report.
• Measuring our sustainability performance using a progress toward goals chart. This is our fourth year to rate our performance in key areas in this manner. We will refine and improve the dashboard measures in coming years.

How data in this report were verified

The Weyerhaeuser data contained in this report are drawn from:

• Established internal databases that are used regularly by our operations.
• Environmental data reported to the EPA.
• Annual internal surveys.

Environmental data are obtained in a number of ways at Weyerhaeuser facilities, including physical measurement, representative and other sampling, application of standard government factors, and recognized industry factors. Calculations were performed using measured data as well as commonly recognized engineering standards. All equations and estimations that were used in calculating environmental data reported in this document have been accepted industrywide and by all pertinent regulatory authorities.

In addition, each section of the website is reviewed by an internal subject-matter expert to ensure accuracy. The final draft of the website is reviewed by members of Weyerhaeuser’s Disclosure Committee and key senior leaders to ensure material information is accurately communicated. Each page notes the date content was last reviewed and updated as needed on the bottom of the page.

Weyerhaeuser has evaluated options for external verification of data and does not currently externally verify all of the data included in this report. We continue to monitor stakeholder interest and trends in external verification.