ESG report preparation begins with materiality assessment, identifying which environmental, social, and governance topics matter to stakeholders and business performance. Companies map their reporting frameworks to GRI, SASB, TCFD, and CSRD. They collect quantitative and qualitative data across operations. They also conduct stakeholder consultation and draft narrative sections. Companies obtain third-party assurance and publish the findings in integrated or standalone reports. Requirements vary: the CSRD mandates double materiality, and the ESRS standards apply to large EU companies. SECR requires energy and carbon data for UK firms. SEC proposed rules would require climate risk disclosure for US public companies. Canada relies on voluntary frameworks pending anticipated regulation. This guide walks through Siemens AG’s 2024 CSRD implementation. It covers 300,000 employees across 18 sustainability topics. The guide shows what robust ESG reporting requires. It also explains what it costs and where companies commonly fail.
How did Siemens identify their 18 material sustainability topics?
Siemens AG conducted a double materiality assessment in 2023, preparing for CSRD compliance in fiscal year 2024. The process started with a longlist of 47 potential topics. These topics were drawn from European Sustainability Reporting Standards (ESRS) and sector-specific guidance for industrial manufacturing and technology. They also included peer benchmarking, regulatory horizon scanning, and media analysis of stakeholder concerns. The longlist included environmental topics such as climate change, pollution, water, biodiversity, and circular economy. It covered social topics such as workforce conditions, workers along the value chain, affected communities, and consumers. Governance topics encompassed business conduct, corruption prevention, and lobbying practices.
Double materiality assessment evaluates each topic from two perspectives. Impact materiality asks: Does our business cause or contribute to significant positive or negative effects on people or the environment? Financial materiality asks: Does this topic create risks or opportunities affecting our financial position, performance, or cash flows? A topic qualifies as material if either perspective meets significance thresholds. Siemens determined that 18 of 47 topics met materiality criteria.
The assessment involved structured stakeholder engagement across 12 groups. Employees were surveyed, with 8,500 workers globally participating. 120 major accounts were interviewed. Suppliers consulted with 200 strategic partners. Investors engaged with 45 institutional holders, representing 62% of the shares. Regulators reviewed feedback from the German Federal Financial Supervisory Authority and the European Commission. Civil society organisations held a dialogue with 15 NGOs covering labour, environment, and human rights. Local communities near major sites participated in workshops in 8 locations. Internal leadership included board and senior management sessions.
For impact materiality, Siemens scored each topic on severity (scale of harm/benefit), scope (number of people or extent of environmental effect), and irremediability (whether impacts can be reversed). Climate change was rated at the highest severity due to greenhouse gas emissions across the value chain. Its global scope affects billions. There is partial irremediability because of the long atmospheric residence time of CO2. For financial materiality, topics were scored on magnitude (potential financial effect), likelihood (probability of occurrence), and timeframe (short-, medium-, or long-term).
The final materiality matrix plotted 18 material topics. They include climate change mitigation and adaptation, energy, and air/water/soil pollution. Other topics are water and marine resources, the circular economy, and biodiversity. It also covers the workforce conditions, workers in the value chain, and affected communities. Additionally, it includes consumers and end users, business conduct, including anti-corruption, and data privacy/cybersecurity. Each topic maps to specific ESRS standards requiring disclosure. Siemens documents the materiality assessment process, stakeholder inputs, scoring methodology, and material topic justifications in a 78-page appendix to their sustainability report.
Which reporting frameworks should companies use?
Framework choice depends on regulatory requirements, stakeholder expectations, and reporting goals. Siemens uses multiple frameworks in parallel: CSRD/ESRS for mandatory European disclosure, GRI Standards for comprehensive sustainability reporting, SASB Standards for investor-focused materiality, TCFD recommendations for climate-related financial disclosures, and UN Global Compact Communication on Progress for principles-based reporting.
The Corporate Sustainability Reporting Directive (CSRD) is mandatory for large EU companies exceeding 250 employees, €50 million revenue, or €25 million balance sheet. Siemens must follow European Sustainability Reporting Standards (ESRS) covering cross-cutting standards (ESRS 1 general requirements, ESRS 2 general disclosures), environmental standards (E1-E5 covering climate, pollution, water, biodiversity, circular economy), social standards (S1-S4 covering own workforce, workers in value chain, affected communities, consumers), and governance standards (G1 business conduct). The first CSRD-compliant reports cover fiscal year 2024 and were published in 2025.
GRI (Global Reporting Initiative) Standards offer the most comprehensive voluntary framework. The modular structure includes universal standards (GRI 1 foundation, GRI 2 general disclosures, GRI 3 material topics) and topic-specific standards covering 33 economic, environmental, and social topics. Siemens has reported using GRI since 2008, providing continuity and comparability. GRI emphasizes impact on economy, environment, and people regardless of financial materiality—aligned with CSRD’s impact materiality lens.
SASB (Sustainability Accounting Standards Board) Standards provide industry-specific metrics for 77 sectors focused on financially material sustainability information. Siemens reports using the SASB Industrial Machinery & Goods standard and the Electrical & Electronic Equipment standard across different business divisions. SASB’s investor-oriented approach complements CSRD’s broader stakeholder perspective. The framework identifies 5-15 material topics per industry with standardized metrics enabling peer comparison.
TCFD (Task Force on Climate-related Financial Disclosures) recommendations structure climate disclosure around governance, strategy, risk management, and metrics/targets. While not a standalone reporting standard, TCFD provides the architecture for climate sections within broader reports. CSRD ESRS E1 largely incorporates the TCFD structure. UK companies over 500 employees must include TCFD-aligned disclosure in annual reports under mandatory requirements from 2022. The SEC’s proposed climate rule adopts a similar TCFD-based structure.
The IFRS Sustainability Disclosure Standards (issued in 2023) provide baseline global standards that focus on enterprise value and investor needs. IFRS S1 covers general sustainability disclosures, while IFRS S2 specifically addresses climate. These are designed for incorporation into jurisdictional regulations; Canada’s anticipated mandatory climate disclosure will likely adopt IFRS standards. The EU developed ESRS in parallel with substantial alignment to IFRS but a broader scope covering impact alongside financial materiality.
What data infrastructure does ESG reporting require?
Siemens built an integrated ESG data management platform. It consolidates information from 47 different source systems. These systems include financial reporting (SAP S/4HANA), operations management (MES systems), and human resources (SuccessFactors). They also cover environmental health and safety (Enablon), supply chain (SAP Ariba), and energy management (IoT sensors and SCADA). Additionally, the platform uses sustainability-specific tools such as carbon accounting software, supplier engagement platforms, and stakeholder management systems.
Data collection follows a bottom-up approach. Local sites report monthly or quarterly metrics through standardised templates. These include energy consumption, encompassing electricity, natural gas, diesel, and renewable sources. They also report water withdrawal and discharge, categorised by source and quality. Waste generation is reported by type and disposal method. Air emissions include Scope 1 GHG, NOx, SOx, and particulates. Employee metrics cover headcount, turnover, training hours, injury rates, and diversity statistics. Supplier assessment results include audits, corrective actions, and sustainability ratings.
The platform applies validation rules checking data completeness, range limits (flagging outliers for review), logical consistency (e.g., water discharge cannot exceed withdrawal plus rainfall), and trend analysis (highlighting unexpected period-over-period changes). Siemens identified and corrected 1,847 data quality issues in 2023 through automated validation before data aggregation. Common errors included unit-conversion errors (kWh reported as MWh), double-counting in shared facilities, and incomplete temporal coverage (missing months).
Qualitative data requires different handling. Narrative disclosures on governance structures, policies, stakeholder engagement processes, and climate scenario analysis involve coordination across departments. Siemens uses a content management system with workflow assignments, review/approval chains, version control, and cross-reference checking to ensure consistency between quantitative metrics and qualitative narratives. The 2024 sustainability report involved contributions from 340 employees across 28 departments coordinated through this system.
Third-party assurance requires audit trail documentation. Every reported figure must trace to source data with clear calculation methodologies, estimation assumptions, and data ownership. Siemens maintains a data dictionary documenting definitions, measurement procedures, responsible parties, and update frequencies for 280 ESG metrics. Assurance providers sample datasets, test controls, review methodologies, and trace selected figures to source documentation.
How does stakeholder engagement inform reporting content?
CSRD and GRI both require systematic stakeholder consultation. Siemens conducts ongoing engagement rather than one-time exercises. Employee engagement operates through works councils (German co-determination), global employee surveys (biennial, 78% participation rate in 2023), and focus groups on specific topics (conducted 24 sessions on sustainable workplace practices in 2023). Key employee concerns identified include just transition planning as the company exits fossil fuel projects, upskilling for green technology roles, and work-life balance amid business transformation.
Investor engagement happens through quarterly earnings calls, annual general meetings, dedicated ESG investor days (held March 2024 with 250 participants), and one-on-one meetings with major shareholders. Institutional investors particularly pressed for Scope 3 reduction targets, climate scenario analysis quantifying financial implications under 1.5°C and 3°C pathways, and disclosure of policy advocacy positions on climate regulation. These inputs directly shaped Siemens’ climate strategy section and led to enhanced disclosure on climate lobbying activities.
Supplier engagement involves annual sustainability assessments for strategic suppliers (conducted 890 assessments in 2023), on-site audits (428 locations), and collaborative improvement programs. Suppliers requested clearer communication of Siemens’ sustainability expectations, longer lead times for new requirements, and technical support for decarbonization efforts. Siemens incorporated supplier feedback sections in the value chain chapter explaining how the company supports supplier transitions including shared best practices, financing programs, and joint innovation projects.
Civil society engagement includes participation in multi-stakeholder initiatives (UN Global Compact, World Business Council for Sustainable Development, Responsible Business Alliance), partnerships with NGOs on specific issues (water stewardship with WWF, circular economy with Ellen MacArthur Foundation), and response to stakeholder surveys and rankings (CDP, EcoVadis, MSCI ESG Ratings). NGO feedback highlighted concerns about biodiversity impacts from infrastructure projects, water use in water-stressed regions, and human rights risks in electronics supply chains.
The sustainability report directly addresses material stakeholder concerns. Each material topic chapter includes a “stakeholder perspectives” subsection that summarises key concerns raised and explains the company’s response. This transparency builds credibility and demonstrates how external input shapes strategy. It also satisfies the CSRD ESRS 2 requirements for describing stakeholder engagement processes and how stakeholder views inform decision-making.
What does third-party assurance examine?
Siemens received limited assurance on its 2024 sustainability report from KPMG under ISAE 3000 (Revised) and AA1000AS standards, covering quantitative data such as GHG emissions Scope 1-2-3, energy use, water consumption, waste generation, employee metrics, and supply chain data. It also included qualitative aspects like the materiality assessment process, governance descriptions, and stakeholder engagement. As per CSRD, independent assurance begins with fiscal year 2024 reports (published 2025), starting with limited assurance and transitioning to reasonable assurance by 2028.
Limited assurance uses analytical procedures, inquiries, and sampling instead of thorough testing. KPMG reviewed calculation methods and assumptions. They tested controls for data capture and aggregation, interviewed staff, and checked source documents for selected data points. They visited 8 Siemens locations to assess local data collection and compared reported data with underlying records.
For GHG emissions, assurance covered the accuracy of emission factors and activity data through sampling electricity bills, fuel receipts, and transport records. It assessed Scope 3 models through a methodology review and confirmed that all entities were included within the organisational boundary. Assurance providers tested 12% of Scope 1-2 data and 8% of Scope 3 data by emissions volume, selecting samples based on materiality and risk.
For qualitative disclosures, assurance examined whether descriptions of policies, processes, and governance structures accurately reflect actual practices. This involved reviewing board minutes confirming sustainability governance claims, examining stakeholder engagement records supporting engagement descriptions, and comparing disclosed policies to actual documented policies. Assurance providers identified 23 instances in which report language overstated program maturity or scope, prompting revisions before publication.
The assurance statement outlines the scope, standards, procedures, limitations (e.g., exclusion of forward-looking statements), and conclusion. For limited assurance, the conclusion is negative assurance; nothing has come to our attention that suggests the sustainability information is not prepared in accordance with the reporting criteria. Reasonable assurance, required under CSRD from 2028, provides positive assurance that the sustainability information aligns with the reporting criteria.
How do CSRD requirements compare across Germany, the UK, the US, and Canada?
Siemens AG’s parent company must comply with full CSRD requirements for the fiscal year 2024, necessitating ESRS-aligned disclosures in management reports alongside financial statements, with independent assurance expected by 2028. Digital tagging in XBRL format and publication within 4 months of the fiscal year-end are mandatory. Siemens plc in the UK also has to adhere to SECR and UKSDR, which require the disclosure of Scope 1-2 emissions and TCFD-style climate disclosures, including governance and risk management, targeting 2025-2026 for implementation, primarily focusing on climate issues with limited broader ESG considerations.
Siemens Corporation (US subsidiary) would be subject to the SEC’s proposed climate disclosure rules if finalized, which include climate-related risks, GHG emissions (Scope 1-2 for all public filers, Scope 3 if material), and climate-related targets and transition plans. Governance, risk management processes, and the financial impact of severe weather events are also required. Attestation requirements would phase in for large filers, and rules differ from CSRD with a narrower scope (climate only), materiality threshold (SEC financial materiality standard), and integration in Form 10-K instead of a separate sustainability report.
Siemens Canada, while not mandated to report on sustainability, voluntarily adopts the GRI and TCFD frameworks. They are preparing for upcoming IFRS SDS guidance, likely mandatory for federal entities by 2025-2026, which will focus on climate disclosures aligned with IFRS S1 and S2. In anticipation, the company is investing CAD $1.8 million in sustainability data systems in 2023. The varied reporting landscape presents compliance challenges due to the need for a master sustainability dataset that caters to multiple jurisdictions: CSRD-ESRS for the EU, SECR and potential UKSDR for the UK, expected SEC rules for the US, and CSSB standards for Canada. The company experiences 75% data overlap, but 25% of the requirements are specific to each jurisdiction, necessitating parallel data collection. Their total reporting expenses reached €14.2 million in 2023.
What does end-to-end ESG report preparation cost?
Siemens’ 2024 sustainability reporting budget totaled €14.2 million covering CSRD, GRI, SASB, TCFD, and jurisdiction-specific requirements. Cost breakdown: data management platform and IT systems (€4.8 million including software licenses, system integrations, and technical support), internal personnel (42 FTEs dedicated to sustainability reporting at average €105,000 per FTE = €4.4 million), external assurance (€2.1 million for limited assurance across all locations and subsidiaries), materiality assessment and stakeholder engagement (€1.2 million including survey platforms, workshop facilitation, third-party consultation), report production and design (€680,000 for content management, translation into 6 languages, graphic design, web development), and legal and compliance review (€420,000 for ensuring regulatory alignment).
First-year CSRD implementation involved additional one-time costs of €6.3 million: gap analysis against ESRS requirements (€380,000), double materiality assessment (€890,000), data infrastructure enhancements (€2.7 million for new data collection capabilities and system modifications), internal training (€420,000 for 340 contributors across departments), and external advisory support (€1.9 million for technical guidance on ESRS interpretation and implementation). Steady-state CSRD compliance costs are estimated at €9.8 million annually from 2025 forward.
Mid-sized companies (500-3,000 employees, €50M-500M revenue) budget €400,000-€1.8 million annually for comprehensive ESG reporting depending on operational complexity, geographic spread, and framework adoption. Manufacturing and resource-intensive companies trend toward higher costs due to extensive environmental data requirements. Service and technology companies trend lower with simpler environmental footprints. Companies with established sustainability programs and existing data systems face 30-40% lower costs than those building capabilities from scratch.
Reasonable assurance (mandatory under the CSRD from 2028) will significantly increase costs. Siemens estimates their assurance costs will rise from €2.1 million (limited) to €5.8-7.2 million (reasonable) based on audit firm estimates. Reasonable assurance requires more extensive testing, larger sample sizes, a detailed review of controls, and greater liability for assurance providers. Mid-sized companies anticipate assurance costs increasing by 150-200% when moving from limited to reasonable assurance.
Cost-optimisation strategies include automating routine data collection using IoT sensors and system integrations. Another strategy is centralising data platforms to reduce manual consolidation. They also involve standardising templates and methodologies across business units and geographies. Additionally, they involve expanding the scope of progressive assurance rather than attempting comprehensive coverage immediately. Siemens reduced per-metric reporting costs by 32% between 2020 and 2024 through systematic automation and process improvements despite expanding total metrics reported from 87 to 280.
FAQ
Can companies skip ESG reporting if they’re not profitable?
No, for in-scope companies. CSRD applies based on size thresholds (250+ employees, €50M+ revenue, or €25M+ balance sheet) regardless of profitability. SECR similarly applies to large UK companies, independent of profit status. Many unprofitable startups and growth companies exceed employee or balance sheet thresholds, triggering requirements. Voluntary frameworks like GRI don’t have profitability conditions. Loss-making companies face the same sustainability reporting obligations as profitable peers, though financial constraints may limit reporting sophistication and assurance scope.
How long does materiality assessment take?
Typically, 3-6 months for first-time assessments at large companies. Siemens’ 2023 double materiality process took 4.5 months. This includes 3 weeks for longlist development and 8 weeks for stakeholder engagement such as survey deployment, interviews, and workshops. It also includes 4 weeks for scoring and analysis, 2 weeks for validation and board approval, and ongoing refinement. Smaller companies can complete assessments in 6-10 weeks with focused stakeholder samples and simplified scoring. Materiality should be reviewed annually with full reassessment every 2-3 years or when significant business changes occur (M&A, strategy shifts, new regulations).
Do parent companies report separately from subsidiaries?
Depends on the jurisdiction and consolidation. Under CSRD, parent companies report on a consolidated basis, including all subsidiaries that meet the consolidation requirements set out in accounting directives. Subsidiaries below CSRD individual thresholds are exempt if covered in parent reporting. Large subsidiaries above thresholds report separately, even if included in parent consolidated reporting. Siemens AG reports consolidated covering global operations, while Siemens plc files a separate SECR disclosure in the UK, and Siemens Corporation would file separately under SEC rules. Companies must clearly define organisational boundaries and avoid double-counting or gaps between parent and subsidiary reports.
Can companies use estimates in ESG reports?
Yes, with disclosure requirements. Both CSRD and GRI permit estimation when precise measurement is impractical. Companies must disclose estimation methodologies, assumptions, and data sources. They need to disclose uncertainty ranges and plans to improve data quality over time. Common estimates include Scope 3 emissions using spend-based or average-intensity factors. They also include employee metrics from partial surveys extrapolated to total population. Water use estimates are made at sites without meters. Best practice is progressively replacing estimates with measured data. Assurance providers scrutinise estimation approaches, test the reasonableness of assumptions, and flag estimates lacking adequate support.
What happens if companies miss reporting deadlines?
Consequences depend on jurisdiction. Under CSRD, member states will establish penalties for non-compliance including administrative fines. Germany’s implementation, through the Corporate Sustainability Reporting Directive Implementation Act, includes fines of up to €10 million. Serious violations may result in a 5% penalty of annual turnover. UK SECR violations fall under the Companies Act, with penalties of up to £5,000 for directors. SEC violations of disclosure rules carry civil penalties and potential securities fraud liability. Canada’s anticipated regulations will likely include enforcement provisions. Beyond formal penalties, missed deadlines create reputational risk, investor confidence issues, and increased regulatory scrutiny in subsequent periods.
Should companies integrate ESG into annual reports or publish separately?
CSRD mandates integration into management reports alongside financial statements. This creates a single corporate reporting package. Some companies also publish detailed standalone sustainability reports that provide additional content beyond the mandatory minimums. Siemens publishes a combined Annual Report. It includes a CSRD-compliant management report integrated with financial statements (180 pages). Additionally, there is a detailed Sustainability Information supplement (320 pages) with comprehensive GRI, SASB, and TCFD disclosures. Integration improves consistency between financial and sustainability information and signals strategic importance. Standalone reports allow deeper topic coverage, less technical language, and stakeholder-specific formatting. Many companies adopt a hybrid approach: integrated mandatory disclosure plus voluntary supplementary reporting.