A real estate portfolio team was preparing for its next GRESB submission. The sustainability lead knew the portfolio had made operational improvements during the year, but the evidence sat across supplier portals, spreadsheets, manual readings and site-level assumptions.

The issue was not effort. It was structure. GRESB requires asset-level reporting, and for indicators such as EN1 and WT1, the quality of the underlying data directly affects how confidently energy and water performance can be reported.

Monitor Hut reviewed the metering position across the portfolio and found three common gaps: some assets had strong electricity data but weak water visibility; some had landlord supply data but unclear tenant or shared-service boundaries; and some had consumption totals but no reliable connection between floor area, reporting level and time coverage.

That matters because GRESB does not simply ask for a headline annual total. Data coverage is assessed by area and time, with separate treatment for landlord-controlled and tenant-controlled spaces. For like-for-like calculations, data needs to cover the full year, have positive coverage, and remain consistent across the reporting years.

Monitor Hut installed missing meters and sub-meters where needed, connected existing meters where data was already available, and automated collection across electricity and water supplies. The portfolio data was then structured by asset, utility, reporting level and floor area coverage.

Instead of waiting until submission season to assemble spreadsheets, the team had live platform visibility throughout the year. That meant gaps could be spotted early, consumption patterns could be reviewed while they were still actionable, and GRESB-ready outputs could be prepared with fewer last-minute assumptions.

Explore more examples in our Data Stories, or see how connected data supports compliance and reporting workflows.

In the 2026 GRESB Real Estate Assessment, energy and water data are not just background inputs. EN1 influences data coverage and energy performance scoring, while WT1 influences water data coverage and like-for-like performance. GRESB also recognises third-party review of sustainability data through its Data Monitoring & Review section.

That makes the data foundation important. If energy and water data is fragmented, estimated, unavailable or difficult to map to the right reporting level, teams can spend reporting season trying to explain gaps. With end-to-end monitoring in place, the same data can support compliance, investor reporting and live operational improvement.