GRESB: how the score is built and which building data moves it

A GRESB score is won less and less with written policies and more and more with energy consumption measured asset by asset. This score circulates among your investors, who read it to make portfolio decisions. Yet it often starts from a meter nobody has checked again since handover. Here we follow the data, from meter to score, to show what the assessment rewards and what your reporting must stand up to.

What is GRESB, who asks you for it and how does it differ from a legal obligation or a certification?

Global Real Estate Sustainability Benchmark: definition of a framework created in 2009

The Global Real Estate Sustainability Benchmark (GRESB) is a private organization founded in 2009 and based in Amsterdam^{[1][1]FrameworksGRESB, “About GRESB”: organization founded in 2009, headquartered in Amsterdam, star rating and Green StarSee in sources ↓}. Every year it assesses the environmental, social and governance (ESG) performance of real estate and infrastructure funds^{[2][2]FrameworksGRESB, “Real Estate Standard and Reference Guide”, Management and Performance components, score out of 100See in sources ↓}. Each participant submits its answers on a common portal. The framework is neither a law nor a building certification.

For a fund manager, the GRESB definition boils down to one idea: turning sustainable real estate into data that can be compared from one fund to another.

From real estate to infrastructure: why GRESB is no longer an acronym

The full name no longer describes the whole scope. The framework has expanded to infrastructure: roads, rail, networks and telecoms^{[3][3]FrameworksGRESB, “GRESB Assessments”: benchmark of entities (funds, portfolios) and extension to infrastructure, no building certificationSee in sources ↓}. GRESB Infrastructure assesses an infrastructure fund as well as a single asset, under the label of real assets. The acronym has stayed. It now covers a real estate and infrastructure field that its original name ignored.

Investors, funds and asset managers: who uses the GRESB score

Two groups meet. Participants are the entities assessed: funds, property companies, infrastructure managers. Investor members read the results to inform their capital allocation. In between, real estate asset management carries the actual workload. Asset managers are the ones who fill in the portal, document the answers and then defend the score when an investor asks a precise question.

Is GRESB mandatory for a real estate fund?

No law requires it. The framework remains voluntary in law, required in practice: a management mandate or an institutional investor's responsible investment policy is enough to make participation unavoidable. Presenting it as optional to a committee is an understatement. A participant absent from the GRESB assessments loses an argument in the investment decision and leaves its portfolio with no point of comparison.

A benchmark of entities, not a building certification

The Global Real Estate Sustainability Benchmark scores a fund or a portfolio. It certifies no building^{[3][3]FrameworksGRESB, “GRESB Assessments”: benchmark of entities (funds, portfolios) and extension to infrastructure, no building certificationSee in sources ↓}. It is a benchmark of entities: the score positions a vehicle against its peers within the same assessment cycle. The “benefits of a GRESB certification” often mentioned are therefore those of a comparative score. They come down to visibility with investors and a yardstick for year-on-year progress.

Did you know? A building cannot “be GRESB”. The framework assesses entities and issues no building certificate^{[3][3]FrameworksGRESB, “GRESB Assessments”: benchmark of entities (funds, portfolios) and extension to infrastructure, no building certificationSee in sources ↓}. A GRESB plaque on a façade is therefore a misunderstanding.

Building certifications do have their place in the score, though, at another level.

Green Globes and building certifications: what they earn in the score

They count in the Performance component, which rewards the share of the portfolio covered by a building certification^{[4][4]FrameworksGRESB, “Real Estate Reference Guide”, Building Certifications indicator of the Performance component; Infrastructure Fund, Asset and Development Asset variantsSee in sources ↓}. Green Globes, the North American scheme of the Green Building Initiative, is among the recognized certifications^{[5][5]Studies and reportsGreen Building Initiative, “Green Globes”, certification recognized by GRESBSee in sources ↓}. A certification does not replace measured consumption, though. We have seen buildings certified at handover overconsuming three years later, for lack of monitored operation.

EPRA sBPR, the European cousin for listed property companies' reporting

European listed property companies follow another framework: the EPRA sBPR, for Sustainability Best Practices Recommendations. EPRA sets out sustainability reporting recommendations, without any rating. The overlap with GRESB is wide: energy, GHG, water, waste and certifications. The same sustainability data therefore feeds the annual ESG reporting and the GRESB assessment cycle, provided it is correct at the source.

GRESB, Décret tertiaire, BACS decree: who requires what, who scores what

A benchmark, two decrees and certifications get mixed up in committees. They do not require the same thing and do not target the same entity. The BACS decree (French decree 2020-887 on building automation and control systems, BACS) requires equipment. The following table puts each framework in its place.

The last row matters most. One metering data point, several exercises: a site's consumption feeds the Décret tertiaire (France's tertiary decree on energy savings in commercial buildings), the BACS trend history and the Performance indicator. For the OPERAT declaration, it is the same data as for the GRESB portal (OPERAT being the French government platform where Décret tertiaire consumption is declared). Wrong at the source, this utility data becomes wrong three times. This information must be made reliable before reporting, never after.

Why does the GRESB score weigh on investment and how is it built?

Comparing yourself with peers on a common grid

Each participant receives a benchmark report that positions it against comparable funds, by region and by asset type. The grid is common: the overall ranking can be read without any debate on method, including by investor relations teams. In an allocation decision, a score gap against peers weighs more than a forty-page CSR report.

Capital allocation: what institutional investors do with the score

In capital allocation, the score acts as a filter. An institutional investor checks it before entering a real assets fund. It then uses it to require access to data from the fund manager. A low score does not always close access to capital. It triggers precise questions before the investment committee. The commitment asked of the manager then concerns a trajectory rather than a level.

Transition risk: the score as a signal on the assets' trajectory

For a fund manager, the score works as a risk management tool: it signals whether an asset is drifting or following a sustainable trajectory. An informed reader cross-checks it with the CRREM thresholds. Over the long term, an asset whose energy consumption does not fall ends up discounted. The measured energy consumption remains the deciding indicator.

Reporting to real estate investors: SFDR, ESRS E1 and reused data

The data entered in the portal is not used only once. Real estate investor reporting draws on the same consumption figures: funds' SFDR indicators, the climate section of ESRS E1 and property companies' ESG reporting. Sustainability data must stay consistent from one document to the next. A consumption figure corrected here and forgotten there quickly ruins the credibility of the information.

Real Estate, Infrastructure, Development: which assessment for which asset

The framework distinguishes four assessments: Real Estate and three Infrastructure variants (Fund, Asset and Development Asset)^{[2][2]FrameworksGRESB, “Real Estate Standard and Reference Guide”, Management and Performance components, score out of 100See in sources ↓[4][4]FrameworksGRESB, “Real Estate Reference Guide”, Building Certifications indicator of the Performance component; Infrastructure Fund, Asset and Development Asset variantsSee in sources ↓}. The GRESB Real Estate Assessment targets funds and property companies that hold buildings in operation. Projects under construction fall under a separate Development Benchmark. A manager of networks or roads answers at the level of the fund or of each asset.

The Management component: policies, governance and stakeholder engagement

The Management component, one of the components of the score, assesses what the entity has organized: environmental policies, governance, risk management and stakeholder engagement. A policy can be declared in one sentence. Yet the framework expects evidence: a signed procedure, meeting minutes, a mandate clause. These assessment criteria reward organization, rarely results. That is the strength of this component and its limit.

The Performance component: energy, GHG, water, waste and certifications

With the Performance component, the exercise changes nature. Its indicators are measured asset by asset: energy consumption, GHG emissions, water, waste and building certifications. Each asset declares its consumption, the floor area covered by meter readings and the year-on-year change. Energy efficiency is demonstrated with meter readings. This is where the building's environmental data enters the score.

GRESB score out of 100, stars and Green Star: reading the score without misinterpretation

The GRESB score is absolute: a score out of 100 that adds up Management and Performance. The star rating is relative. It ranks the entity from 1 to 5 stars according to its rank among its peers^{[1][1]FrameworksGRESB, “About GRESB”: organization founded in 2009, headquartered in Amsterdam, star rating and Green StarSee in sources ↓[2][2]FrameworksGRESB, “Real Estate Standard and Reference Guide”, Management and Performance components, score out of 100See in sources ↓}. The diagram below separates the two readings.

The GRESB rating is therefore read in two steps. A stable score can lose a star if the rest of the benchmark improves faster. The Green Star, for its part, follows a threshold logic separate from the ranking.

Fundamentals and “Road to Performance”: where the rating is heading

Our reading of recent announcements is clear: GRESB performance is taking precedence over declarations. Fundamentals and “Road to Performance” shift the weight of GRESB assessments toward measured indicators. We will wait for the Scoring Document before quoting dates and weightings. For the assessment of a real estate portfolio, the consequence is already clear: without reliable data, the score will eventually plateau.

How to improve your GRESB score: metering data before written policies?

Management levers, Performance levers: where points are really won

Management points are won in one assessment cycle. A signed energy policy, a tenant engagement procedure and a named person in charge can be produced in a few weeks. Performance points take several years, because they require consumption that is measured and then compared. To improve your GRESB score in a lasting way, the goal is not to write one more policy. It is to make your meters credible.

Data coverage: why it weighs so heavily

Data coverage measures the share of floor area covered by actually measured consumption rather than estimated consumption. Missing data is often filled with an estimate. On the spreadsheet, the property portfolio looks covered. In the building, nobody has read the meter. The gap rarely comes from the main meter. It comes from tenant areas, disconnected sub-meters and utility data never reconciled with the BMS.

Like-for-like: two comparable years on a stable scope

Like-for-like compares the consumption of the same asset over two consecutive years. It assumes a stable scope. A disposal, a major refurbishment, a replaced meter or a floor left vacant for six months is enough to take the asset out of the comparison. On a real estate portfolio, reading a decrease over time requires a log of operating events. Nobody keeps one spontaneously.

Collecting the consumption of an entire portfolio without errors

GRESB data collection always stumbles on the same points. Tenant consumption escapes the landlord without contractual access to tenants' bills. The BMS and the supplier's bill contradict each other for the same building. A sub-meter gets added to its own main meter: the double count inflates consumption without anyone noticing.

This check protects all the sustainability data that flows from it, all the way to the portal.

What is a GRESB score worth when the meters are wrong?

Not much. A GRESB score calculated on estimates measures the quality of reporting, rarely that of operations. The risk is optimizing a score rather than practices: gaps get filled, evidence gets polished and the building consumes just as much. A reduction measured according to the IPMVP protocol, with weather correction based on heating degree days (HDD), stands up to an auditor. That is the information that serves an investment decision.

How does a GRESB assessment cycle unfold and what should you prepare before the portal opens?

Registration and portal opening

An assessment cycle follows four stages, always in the same order. Here they are, with what each one expects from your team.

The GRESB process starts with the registration of the participating entity on the portal. The participant defines access rights there: who enters data, who validates, who reads the results. The calendar must be checked with GRESB every year. The allocation of roles, however, is decided beforehand.

Collection, data entry and supporting evidence in the portal

Next comes data entry. Consumption is entered asset by asset, with floor areas, periods and measured share. The Management component requires supporting evidence: a signed policy, a procedure, meeting minutes. The assessment gives little credit to a claim without a document. This data collection phase remains the longest, especially when access to utility data goes through three service providers.

Submission and validation of answers

Third stage: submission, on the date set by that year's calendar. GRESB then checks the consistency of the answers and may ask for clarification. The assessment methodology is republished every year. Reread it before submitting, because a modified calculation rule changes how your reporting is read.

Results, benchmark report and discussion with investors

The last stage delivers the results. Each participant receives its score, its GRESB rating in stars and a benchmark report that positions it against its peers. This document mainly serves the dialogue with investors: they compare, question the gaps, ask for a plan. This engagement with each investor is prepared with figures you know how to explain.

What Foobot does upstream of your GRESB reporting

BMS advisory: making the portfolio's meters reliable before the assessment cycle

With BMS advisory, we put the metering chain back in order before it feeds any reporting. Our teams spot disconnected meters, gaps in trend history, double counts and invisible drifts. Each building comes out with three lists: reliable points, points to fix, missing data access. Your utility data becomes data you can defend in front of an investor again.

A GRESB score is only worth what your meters are worth

The framework is shifting its points toward what can be measured. A GRESB score will rely less and less on well-written policies and more and more on consumption that is comparable from one year to the next. Metering stops being an operator's topic. It becomes an asset management topic, read by those who make investment decisions.

Start with what does not depend on the portal: knowing which meters are reliable, which ones lie and which ones no longer report anything. Your data is worked on before the assessment cycle, never during it. Have the metering chain of your property portfolio checked, meter by meter, before the next portal opening.

make your portfolio's meters reliable

FAQ - GRESB