Tania Soussan-Watt, Sustainability Writer & Editor, Environ
Get Ahead of ESG Assurance Season: Key Steps for a Smooth Process
The start of spring is right around the corner and ESG assurance season is ramping up, so, if you’re preparing or have completed contracting your assurance scope, it’s the perfect time to take a few steps to get ready and ensure the process goes smoothly.
Our ISOS Group assurance and verification team, a division of Environ Energy, is ready to support organizations in ensuring the credibility and accuracy of their sustainability reporting and data disclosures. Third-party assurance provides companies with reliability of data to meet stakeholder expectations and regulatory demands.
By doing some groundwork in advance, you can maximize the ESG assurance process, saving time and reducing hassles down the road. Here are five key steps you can take now:
- Review Your Reporting Boundaries: Ensure that your reported information reflects operational, workforce, asset and site changes such as acquisitions, dispositions, expansions and downsized spaces. Be prepared to provide a detailed list of your footprint and facilities/assets separate from your reported metrics.
- Familiarize Yourself with Standards: Take time to review reporting standards that offer guidelines and updated requirements on data preparation such as the Greenhouse Gas Protocol, CDP and the GRESB assessment guidelines. It’s also a good idea to take a look at assurance standards whose criteria can translate into guidance on internal audit procedures — AccountAbility, for which ISOS Group is a licensed assurance provider, is a good example.
Our ISOS Group assurance team also is beginning review of the International Auditing and Assurance Standards Board’s (IAASB) approved International Standard on Sustainability Assurance 5000 (ISSA 5000) to understand how this standard could adjust the assurance landscape.
- Prepare Your Data Accordingly: Per the contracted scope with your provider, you’ll want to ensure that your data is prepared accordingly. Steps could include: 1) updating factors or assumptions used to the most appropriate recent year, 2) if you request data from stakeholders, tenants or procurement teams, it’s important to confirm timelines and expectations and 3) for assurance of environmental data, ensure that your datasets are in a proper, detailed format with evidence of data sourcing, conversions, totals, estimates and assumptions. Your scope of work will dictate the exact needs of how your data should be prepared.
- Update Your Documentation: Documenting data collection and reporting approaches in an environmental management system (EMS), inventory management plan (IMP) or other sustainability process document is best practice. Many of the elements included within these documents — such as data management, estimations and methodologies applied — will be requested by the assurance team, and having the information readily available will streamline the process.
- Complete an Internal Review: Frequent data collection and review is ideal as it reveals consumption patterns and identifies potential issues or operational changes, such as vendor or meter changes. Collecting data regularly also reduces the burden and timeline of the assurance process by resolving identified issues early and preparing contextual data to share with the verifier. Review annual datasets before they’re finalized to ensure variations and reporting boundaries are appropriate. A good year-over-year threshold to keep in mind for environmental data: Thresholds for detecting outliers vary between 20% and 30% (for like-for-like assets) within GRESB’s data validation process.
To learn more or get support in preparing for ESG assurance, contact us here. Our ISOS Group assurance team at Environ Energy specializes in third-party verification, helping organizations enhance the credibility of their sustainability reporting and streamline the assurance process. Let us help you navigate standards, optimize data preparation, and ensure a smooth assurance experience.
Download our printable preparedness checklist here – Assurance and Verification Checklist 2025