Understanding the GRESB Estimations Audit Report – Scaler

Purpose of this article

This article explains how to use the Estimations Audit Report that accompanies the GRESB Spreadsheet. The audit shows how each reported figure was built, identifies the share of estimated data in each value, and confirms compliance with GRESB's data estimation rules.

When to use this guide

You are reviewing a GRESB submission and need to evidence how reported numbers were built

An external auditor or consultant is reviewing your GRESB Asset Spreadsheet

You want to confirm that estimated data sits within GRESB's 20% and three-month caps

You need to demonstrate the estimation methodology to a portfolio manager or GRESB submitter

You are troubleshooting unexpected values in the GRESB Spreadsheet output

Generating the report

The Estimations Audit Report is generated automatically whenever you download a GRESB Spreadsheet with the Include estimated data toggle enabled.

To generate the audit:

Navigate to Reports Portal → GRESB Spreadsheet and open the report for the relevant company and portfolio.

Click Generate report.

In the Generate report modal, turn on Include estimated data.

Select an estimation method:

All client-provided estimates (default; may exceed GRESB limits)

GRESB-compliant, client-provided estimates

GRESB-compliant, client-provided estimates + linear extrapolation

Click Generate.

The download contains the standard GRESB Asset Spreadsheet and a separate file named with the suffix Estimations Audit.xlsx containing the audit workbook.

The audit workbook is generated for all three estimation methods. The columns shown in the audit change based on which method was selected: the All client-provided estimates method shows uncapped values in the Manual Estimates (full) column, the two GRESB-compliant methods show the capped and linear extrapolation columns instead.

[Screenshot: Generate report modal showing the Include estimated data toggle and the three estimation method radio options, crop tightly to the modal]

What's included in the audit

The audit workbook contains seven tabs:

Compliance, the export cover with processing metadata and the chosen estimation method

Energy, energy consumption split out per asset, reporting level, area, and utility

GHG, GHG emissions split out per asset and reporting area

Water, water consumption split out per asset and reporting area, including reused and recycled water

Waste, waste streams split out per asset, hazard category, and disposal route

Explanation(s), side-by-side mapping of every GRESB estimation rule against Scaler's implementation

Lists, reference data (property types, procurement codes, certifications); not intended for reviewer use

Compliance tab

The Compliance tab is a single header on every audit. It contains:

Date and time of processing

Company and portfolio

The estimation method selected on the modal (All client-provided estimates, GRESB-compliant, client-provided estimates, or GRESB-compliant, client-provided estimates + linear extrapolation)

Data completion flag

The cover restates the chosen method in plain language, so an auditor opening the file knows immediately what they are looking at.

Energy, GHG, Water, and Waste tabs

For every asset × reporting level × area × utility, each tab breaks the reported number into the same six columns:

Reported, the value actually submitted to GRESB

Actual, pure metered data, no estimation

Manual Estimates (full), uncapped manual estimates; only shown for the All client-provided estimates method

Manual Estimates (capped), manual estimates trimmed to GRESB's 20% and three-month caps; only shown for the two GRESB-compliant methods

Scaler Linear Extrapolation Estimates, linear extrapolation that fills remaining gaps; only shown for the GRESB-compliant + linear extrapolation method

Percentage estimated, share of the reported value coming from estimation

Where applicable, each block also includes Floor Area Covered and Maximum Floor Area.

Reporting hierarchy per tab

Energy: Whole Building, Base Building (Shared Services, Common Areas), Tenant Spaces (Landlord-Controlled, Tenant-Controlled), Outdoor / Exterior / Parking, Non-Operational (EV Charging Stations), and Renewable Energy (five procurement categories). Each level is split by Electricity, Fuels, and District Heating & Cooling.

GHG: Whole Building and Outdoor / Exterior / Parking, split by location-based and market-based factors.

Water: Whole Building, Base Building, Tenant Spaces, Outdoor / Exterior / Parking, plus Reused and Recycled (water reuse, capture, extraction, purchased).

Waste: Whole Building (Hazardous vs Non-hazardous waste streams) and Proportion of Waste by Disposal Route.

Asset name, property type, and reporting year stay frozen on the left of each tab.

[Screenshot: Energy tab showing the column structure with Reported / Actual / Manual Estimates / Linear Extrapolation / Percentage estimated columns, crop to show one reporting level fully expanded]

Compliance highlighting

Where a manually provided estimate exceeds GRESB's rules, the related cells are filled red. A value is flagged when its capped figure falls below its uncapped figure, which indicates that Scaler had to trim estimates to keep the submission within GRESB's limits.

Red cells do not mean the submission is non-compliant. They mean the underlying manual estimate would have been non-compliant without Scaler's trimming. The reported value is still within GRESB's rules.

[Screenshot: Example of red compliance highlighting on an asset row in the Energy tab, crop tightly to two or three highlighted cells]

Explanation(s) tab

The Explanation(s) tab maps every GRESB data estimation rule against Scaler's implementation in the GRESBLinearExtrapolationModel. Rules covered:

Rule 1, 20% cap on estimated data

Rule 2, three-month cap

Rule 3, two consecutive reporting years

Rule 4, data consistency (same aspect, area type, utility type)

Rule 5, cross-meter overlapping timeframe

Rule 6, gap-in-the-middle (pick best segment)

Rule 7, no estimation if full year missing

Rule 8, no prorating across area

Rule 9, no generic data sources

Rule 10, waste-specific rules

Rule 11, like-for-like exclusion (355 days)

Monitoring Method Filtering, which monitoring methods Scaler classifies as actual vs estimated

Source: GRESB's published Data Estimation Rules.

How the audit reconciles to the GRESB Spreadsheet

The audit pulls from the same calculation engine as the GRESB Spreadsheet itself. Numbers in the audit always reconcile to the figures submitted to GRESB.

The estimation method selected on the report generation modal determines which estimate columns appear in the audit.

The compliance check compares capped vs uncapped output per asset × utility × area type. Any delta indicates a value that GRESB rules would not have permitted in raw form.

Troubleshooting & common mistakes

The audit file is missing from my download → Check that the Include estimated data toggle was on when generating the report. The audit only ships when this toggle is enabled.

A reported value is red, but I expected it to be clean → Open the asset's meter data and check for manually entered estimates that exceed GRESB's 20% or three-month caps. The red flag means Scaler trimmed an estimate that would have been non-compliant.

The Manual Estimates (full) column is empty → You are looking at a GRESB-compliant export. Re-generate with All client-provided estimates to see uncapped values.

A column I expected is missing → Different estimation methods show different combinations of estimate columns. Check the Compliance tab to confirm which method was used.

Additional resources

Understanding Report 'Audit trail' sheets, audit trail format for other framework reports

Estimated consumption data in Scaler, how Scaler classifies and handles estimated data

Completing a GRESB submission using Scaler, end-to-end GRESB workflow including the Include estimated data toggle

GRESB Data Estimation Rules (official)