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.

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, restated in the workbook's shorthand — for example Manual (capped) + Linear Extrapolation for the GRESB-compliant, client-provided estimates + linear extrapolation mode

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, the time-based share of estimated data, calculated as estimated days divided by the days of actual data availability — the same denominator GRESB's 20% cap is measured against. A value built from 73 estimated days against 365 days of data availability shows 20%, regardless of how much consumption those days carry.

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.

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.

Explanation(s) tab

The Explanation(s) tab shows, for every GRESB data estimation rule, how Scaler applies it to each audit column (Actual, Manual Estimates full and capped, Scaler Linear Extrapolation), with examples. The rule numbering is Scaler's own and is kept consistent across our documentation — GRESB's guidance does not number its rules. Rules covered:

Rule 1, 20% cap on estimated data

Rule 2, three-month cap (across both reporting years combined)

Rule 3, two consecutive reporting years

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

Rule 5, overlapping coverage window

Rule 6, gap in the middle

Rule 7, no full-year estimation

Rule 8, no prorating across area

Rule 9, no generic data sources

Rule 10, waste tonnage exception

Rule 11, disclosure of estimation use

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.

Percentage estimated doesn't match the estimated share of consumption → Expected. The percentage is time-based (estimated days divided by the days of actual data availability), not volume-based, so a high-consumption estimated month and a low-consumption one contribute equally.

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 estimation model methodology, the estimation logic behind the audited values

GRESB Data Estimation Rules (official)