The Arizona State University (ASU) Masters of Sustainability Solutions (MSUS) program connects student teams with real-world clients to solve real-world sustainability problems as a part of the students’ Culminating Experience in the program. This report details the project assigned to our group, the Emissions Data Detectives (EDD), in partnership with our client, Gannett Fleming. This project focuses on calculating greenhouse gas (GHG) emissions from the client’s leased office spaces across the United States and Canada. In excess, GHGs trap heat in the atmosphere, negatively affecting global air quality and human health. In addition, top companies similar to our client are already disclosing their emissions, new legislation is aiming to require such reporting, and stakeholders are trending to gravitate towards firms measuring and reducing their environmental impact. During the first semester of this project, we noticed that Gannett Fleming lacked data on specific utility usage in their leased office spaces, as not all data is shared, standardized, or robust enough for accurate emissions calculations. After conducting a landscape analysis where group members interviewed companies facing a similar problem, the team identified best practices for addressing this issue. Such practices included using mixed methods for calculations based on data availability, leveraging organizational connections for efficient communication with landlords, creating custom communication plans, and using concise language with landlords. The team also conducted an sTOWS analysis to understand better how our research could best be applied to Gannett Fleming’s problem. From there, we developed a project plan that included an Invitation to Participate and Data Request to collect the necessary data. Next, the team outlined strategies for emissions calculations, including applying calculations from the GHG Protocol and compiling all calculations in a navigable spreadsheet. Greenhouse gas calculations were made using a mix of asset-specific data from the Data Request forms and average data from the EPA estimates using equations from Scope 3, Category 8, or Leased Upstream Assets per the Greenhouse Gas Protocol. Emissions were categorized under Scope 3 since the client has no control over the leased offices, and the control approach was used. Final results showed that the emissions calculated for the 8 offices where asset-specific data was used combined with the 31 offices where average data was used totaled 2,390 metric tonnes of CO2e for FY2022. In order to ensure that this project can be helpful to Gannet Fleming long-term, we came up with three main deliverables including a GHG spreadsheet including all calculations and findings, a GHG roadmap with simplified step-by-step instructions of our methodology, and a Sustainable Leasing Policy information to ensure the client’s emissions reduction goals are communicated and considered in the decision-making process for future lease agreements. This version contains results that have been edited to ensure client confidentiality. Offices have been anonymized, and numbers used are not representative of actual emissions findings.