Building a scalable GRESB reporting engine: systems, tools, and governance

As real estate portfolios grow in size and complexity, GRESB reporting increasingly shifts from a reporting exercise to an operating-model challenge. Collecting, validating, and reporting sustainability data across multiple assets, funds, and jurisdictions requires more than effort—effective planning, time management along with the use of pragmatic systems in place.

This is particularly true where data must be sourced from tenants, operators, and third party agents. This article explores the systems, tools, and organizational structures that enable a smooth, repeatable GRESB reporting cycle at scale.

ESG data typically originates at the asset level, often with varying degrees of control by managers. Energy, water, waste, and emissions data may be held by landlords, tenants, utility providers, or managing agents. As portfolios scale, so do variations in lease structures, metering arrangements, and data availability.

The significant reporting challenges may occur at various points in the data collection and transfer journey, starting from data acquisition at the source level i.e. assets themselves. Complexity tends to intensify in the transition between data collection and final submission, where information must be interpreted, normalized, aggregated, and aligned with GRESB indicator definitions. It is at this intersection of collection and consolidation that robust systems, governance, and clear ownership become critical.

For many real estate managers, tenant consumption data collection is one of the most difficult aspects of GRESB reporting. While landlord control is ideal, it is not always feasible, particularly in multi-let buildings, older assets, or portfolios with diverse lease structures. Other challenges include metering setup, access to meters, or the absence of metering altogether.

Data access can also be constrained because of data privacy regulations, requiring manual data requests, follow-ups, and reconciliation. These challenges are often compounded by fragmented data formats, differing reporting periods, and reliance on manual processes such as spreadsheets or emailed invoices, all of which increase the risk of delays, errors, and incomplete coverage. In some cases, multiple layers of agents and fragmented systems result in data passing through several manual interventions before final reporting, increasing the risk of inconsistency and misalignment with GRESB requirements.

However, despite these constraints, effective approaches do exist.

Successful campaigns treat data collection as a structured, ongoing process rather than an annual request.

Evolving technological solutions play a critical role in improving reliability and data coverage:

• Automated meter reads and smart metering solutions, where available, to reduce manual handling and improve accuracy
• Direct data connections with utility providers or third-party data services, reducing reliance on manual collection
• Centralized platforms or data portals that allow asset-level data to be uploaded, stored, and reviewed consistently
• Automated reminders and tracking dashboards to monitor submission status and identify gaps early
• Built-in validation checks to flag incomplete data, incorrect units, or outliers

Some of the practices that work well and are seen to being increasingly used:

• Standardized asset-level data request templates aligned with GRESB metrics and reporting periods
• Clear guidance explaining what data is required, why it matters, and how it will be used, helping data owners understand expectations and context
• Defined submission timelines that align with reporting calendars and lease cycles
• Embedding data requirements into contractual and operational frameworks, such as:
  • Green lease clauses that specify data-sharing expectations and formats
  • Tenant or occupier engagement programs that formalize recurring data requests
  • Operational protocols with managing agents that define roles, responsibilities, and escalation paths

Together, these approaches help shift data collection from an ad hoc, manual exercise to a repeatable process that supports both reporting efficiency and data quality, while creating the traceability required for internal review and future external verification.

Not all data owners and providers will respond at the same pace or with the same level of completeness. Mature reporters therefore take a structured approach to engagement, using a range of communication and coordination mechanisms to support data collection over time:

• Prioritizing engagement with high-impact data providers, focusing effort where data gaps materially affect portfolio coverage or performance metrics
• Using multiple engagement channels, such as formal data requests, follow-up communications, workshops, or coordination through managing agents; as well as conducting engagement activities during non-reporting season.
• Tracking improvement over time rather than expecting immediate completeness
• Demonstrating structured efforts to improve coverage where direct control is limited

This approach aligns closely with GRESB’s emphasis on transparency, documentation, and continuous improvement.

Scalable reporting systems must support both Management and Performance components simultaneously.

Management: policies, processes, and oversight

The Management component requires evidence of governance, policies, roles, reporting, and processes. Effective systems therefore need to:

• Clearly document methodologies, assumptions, and boundaries
• Record roles and responsibilities for data ownership and review
• Maintain version control and approval workflows
• Build policies on environmental issues, highlighting proactive management on topics such as climate change, energy consumption, GHG emissions, renewable energy, waste management, and water consumption
• Ensure that disclosed data is externally checked or assured
• Conduct asset-level environmental and social risk assessments as a standard part of its due diligence process for new acquisitions

These elements demonstrate that ESG reporting is embedded within organizational processes rather than assembled at the point of submission.

Performance: data that stands up to scrutiny

The Performance component relies on quantitative data that is consistent, comparable, and defensible. This requires systems that:

• Distinguish between raw asset-level data and calculated metrics
• Maintain historical records to support year-on-year consistency
• Allow transparent explanation of exclusions, estimates, and data gaps
• Report performance data that is assurable and verifiable

In practice, the quality of Performance data is directly influenced by the strength of Management processes upstream.

Scalable GRESB reporting depends less on organizational structure and more on clearly defined functional accountability. As portfolios expand, reporting challenges typically arise not from a lack of capability but from unclear ownership and fragmented decision-making.

Effective reporting models usually establish the following roles, irrespective of formal job titles:

Asset-level data owners are responsible for the accuracy, completeness, and timely submission of data at the asset level, including tenant-sourced information where relevant. Clear ownership at this stage reduces interpretation risk and ensures issues are identified before data is aggregated.

Managing agents or property managers often play a critical supporting role at asset level, particularly where they are responsible for day-to-day operations and utility management. Where managing agents are involved in data collection or validation, their responsibilities should be clearly defined and reflected in operational agreements or KPIs, including expectations around data timeliness, quality, and documentation. Aligning managing agent incentives with ESG reporting requirements can significantly improve data reliability and consistency.

The central ESG or portfolio lead is accountable for reporting methodology, boundary definitions, and year-on-year consistency. This role ensures that GRESB requirements are interpreted consistently across assets and reporting cycles, preventing methodological drift as portfolios evolve.

An internal reviewer or gatekeeper performs a quality-control function prior to submission or assurance. This role focuses on plausibility and coherence, challenging inconsistencies, unexpected movements, and undocumented assumptions, thereby reducing downstream rework.

Senior sign-off provides organizational accountability for disclosed information. While not responsible for validating individual data points, this role is accountable for the overall integrity and credibility of the submission and helps embed ESG reporting within broader governance frameworks.

Where these roles are clearly defined, GRESB reporting becomes more predictable, auditable, and repeatable. Where accountability is diffused, issues tend to surface late—often during submission or assurance—when they are most costly and disruptive to resolve.

As assurance and verification become more prominent in GRESB scoring, the importance of robust systems increases. Verification may not resolve weak processes—it exposes them. Managers with clear data flows, documented methodologies, and disciplined tools typically experience shorter timelines, fewer clarification requests, and greater confidence in both Management disclosures and Performance data.

To explore the role of assurance in more detail, readers can refer to an earlier GRESB insights’ article on this topic: Build trust and improve data quality through ESG assurance.

This article builds on that foundation by focusing on the operating structures that make effective assurance possible.

At portfolio scale, effective GRESB reporting is less about working harder and more about working deliberately. Systems that support tenant data collection, tools that enforce consistency, and clear ownership structures enable managers to report accurately, repeatedly, and with confidence.

As GRESB reporting continues to play a central role in investor decision-making, the differentiator is no longer effort—it is design. The managers who invest early in scalable reporting engines are better positioned to manage complexity, adapt to evolving expectations, and improve performance over time.

This article was written by Vishal Goel, Director ESG – UK at Earthood Services Limited. Learn more about Earthood Services Limited here.