ESRS E1 Climate Disclosure for Buildings: What Property Firms Must Report (2026)

ESRS E1 is the climate-change reporting standard within Delegated Regulation (EU) 2023/2772, the European Sustainability Reporting Standards. ESRS E1 mandates a complete greenhouse gas inventory covering Scope 1, 2, and 3 emissions across nine disclosure requirements, with mandatory third-party assurance starting FY 2024. Five Scope 3 categories apply specifically to property firms: Categories 1, 2, 11, 13, and 15. Auditors apply ISAE 3000 (Revised) procedures and reject generic industry-average emission factors on portfolio assets.

What does ESRS E1 require for buildings at a glance?

ESRS E1 is the climate-disclosure standard property firms must apply under CSRD, structured as nine disclosure requirements (E1-1 to E1-9) covering transition planning, targets, energy mix, emissions, removals, and financial effects.

DataDrivenAEC’s analysis of the nine disclosures shows the reporting load concentrates in E1-6 for property firms. Scope 3 captures embodied carbon, operational carbon of leased assets, and aggregate portfolio emissions across five separate categories.

What are Scope 3 categories 1, 2, 11, 13, and 15?

Scope 3 categories for real estate are five subsets of the GHG Protocol Corporate Value Chain Standard that map directly to building-related emissions. Property firms must disclose all five under E1-6 unless excluded under a documented materiality test.

Category 1 (purchased goods and services) covers embodied carbon of newly acquired buildings plus materials in renovations. Category 2 (capital goods) covers embodied carbon of new construction projects where the reporting entity is the developer. Category 11 (use of sold products) applies to housebuilders selling to end users, capturing operational emissions transferred to buyers. Category 13 (downstream leased assets) tracks operational carbon of tenant-occupied facilities owned by REITs and landlords. Category 15 (investments) requires the aggregate carbon footprint of underlying portfolio assets, weighted by ownership stake or assets under management.

Categories 1, 2, and 13 are typically material for property firms and rarely qualify for materiality exclusion under the double-materiality test.

Why does ESRS E1 require third-party assurance?

Third-party assurance is the operational change between NFRD and CSRD. NFRD had no assurance requirement; ESRS reports require limited assurance from FY 2024 and reasonable assurance by 2028 under Article 34a CSRD. Auditors apply ISAE 3000 (Revised) procedures.

Auditors reject three reporting practices specifically:

• Generic industry-average emission factors used for Scope 3 calculations on portfolio assets
• Estimates without traceable source data
• Material inventories without environmental product declarations (EPDs) where EPDs exist for the product

The implication for property firms: estimate-based portfolio reporting fails the audit. Asset-level data becomes the required baseline. Architects supplying building-handover packages now sit upstream of a regulated audit trail. EPDs, BIM-derived material quantities, and whole-building LCA outputs per EN 15978 form the verifiable data that survives ISAE 3000 procedures.

The phase-in relief allows estimated values for the first 3 years where measured data is unavailable, on disclosure of estimation methodology.

What asset-level data does ESRS E1-6 require?

Asset-level data under ESRS E1-6 is the per-building emissions baseline auditors will accept under ISAE 3000. Five Scope 3 categories apply to property firms; each demands traceable, measurement-based inputs rather than aggregate factors.

Required data per category:

• Category 1: per-asset whole-building LCA covering modules A1-A3 minimum, A1-A5 preferred, sourced from EPDs × BIM volumes for newly acquired stock only
• Category 2: whole-building LCA per EN 15978 for completed development assets in the reporting year
• Category 11: expected lifetime energy consumption (kWh/m²/year) × emission factor × estimated lifetime, with disclosed building-life assumption (typically 50-60 years)
• Category 13: actual energy bills where the landlord has access, or estimates from EPC ratings × floor area where it does not
• Category 15: portfolio-weighted average across all underlying assets, combining Categories 1, 2, 11, and 13

The data baseline is verifiable, asset-level, and auditable. Portfolio-scale approximations were the standard practice under NFRD; under ESRS they fail.

What are the most common ESRS E1 reporting mistakes?

Common ESRS E1 mistakes are five reporting failures that surface during ISAE 3000 limited-assurance procedures, when correction costs peak.

1. Using industry-average emission factors on owned assets. Auditors reject this for portfolio assets. Asset-level EPD-backed data is the required baseline for Categories 1 and 2.

2. Excluding Category 13 as immaterial. Operational carbon of tenant-occupied facilities is typically material for REITs and landlords. The double-materiality test rarely supports exclusion when leased floor area is significant.

3. Reporting intensity targets only under E1-4. ESRS E1-4 requires absolute reduction targets, not intensity-only metrics. Intensity targets may supplement, never replace.

4. Skipping Category 15 in fund structures. Property funds, pension funds, and REITs investing in underlying assets must report aggregate Category 15 emissions weighted by ownership or AUM. Single-asset reporting at the fund level fails.

5. Double-counting assets across categories. When a building is developed and held, the same asset may appear in Categories 2 and 13. The standard requires the most representative single category, with disclosure of the consolidation choice.

How DataDrivenAEC automates code compliance checking

ESRS E1 disclosure preparation requires asset-level building data — embodied carbon per material, EPD references, and whole-building LCA modules per EN 15978. Pulling this from a project at handover takes 2–4 hours of cross-referencing manually. DataDrivenAEC builds custom agents that run this check on your drawing set and deliver the findings as a structured report. See all agents →

Frequently asked questions

When does reasonable assurance replace limited assurance under ESRS?

Reasonable assurance is targeted by 2028 under Article 34a CSRD, replacing the limited assurance applied from FY 2024. Limited assurance under ISAE 3000 (Revised) requires evidence sufficient to express a negative-form conclusion. Reasonable assurance requires evidence sufficient for a positive-form opinion, similar to financial-statement audits. Property firms should plan for the upgrade by building auditable Scope 3 data trails from FY 2024 onward.

Are Scope 3 Categories 1, 2, and 13 always material for property firms?

Yes, in practice. The double-materiality test (financial materiality + impact materiality) almost always identifies these categories as material for owners, developers, and landlords. Embodied carbon (Categories 1 and 2) and operational carbon of leased assets (Category 13) represent the bulk of a property firm’s value-chain footprint. Exclusion requires explicit justification disclosed in the materiality assessment.

Can a property firm use estimated values for the first ESRS report?

Yes, ESRS allows estimated values during the first 3 years of reporting where measured data is unavailable. The estimation methodology must be disclosed. The phase-in relief was designed to accommodate firms that lack historical asset-level data; from year 4 onward, measured data is the baseline expectation. Firms should treat the 3-year window as a transition period to instrument buildings for measurement-based reporting.

What is the difference between ESRS E1 and the EU Taxonomy?

ESRS E1 is the climate-disclosure standard under CSRD covering greenhouse gas accounting across Scopes 1, 2, and 3. The EU Taxonomy is a classification framework defining environmentally sustainable economic activities. Article 8 Taxonomy disclosures fold into the CSRD Management Report. ESRS E1 reports the emissions inventory; Taxonomy classifies which activities are aligned with the EU’s climate objectives. Both apply to in-scope CSRD firms simultaneously.