Basis of reporting documents

Below are links to our Greenhouse gas emissions Basis of Reporting. These documents provide explanation of the collection and treatment of data used to compile emissions reporting as part of the Annual report and accounts.

Scope 1 and 2 – Basis of reporting

Scope 3 category 15 – Basis of reporting

Scope 3 other categories

Net Zero Banking Alliance Intermediate Targets

Archive

Greenhouse gas reporting methodology 2022

Greenhouse gas reporting methodology 2023

Greenhouse gas reporting methodology 2023 (Scopes 1 and 2)

Greenhouse gas reporting methodology 2023 (Scope 3 categories 3, 5, 6, 7 & 8)

Greenhouse gas reporting methodology 2024

Greenhouse gas reporting methodology 2024 (Scopes 1 and 2)

Greenhouse gas reporting methodology 2024 (Scope 3 categories 3, 5, 6, 7 & 8)

Net Zero Banking Alliance Intermediate Targets 2024

Nature

The Group has undertaken work to assess our dependencies on nature and our potential exposure to nature related impacts. We conducted an initial assessment using the Taskforce on Nature-Related Financial Disclosures (TNFD)’s Leap approach to develop our understanding of nature related risks across our operations and value chain. We used the ENCORE tool to map material impacts and dependencies of our direct operations and downstream value chain.

This has helped to identify nature-related indicators (such as water supply, soil stability, ecosystem condition and pollution) and how they could impact our risk exposure. We assessed these indicators over direct operations as well as our wider value chain.

Certifications & awards

ISO 14064‑1: The Group verify it’s Group 3 emissions in accordance with ISO 14064-1:2018 requirements. The third-party verification was conducted in compliance with ISO 14064-3:2019 standard.

ISO 14001: The Group’s established and comprehensive environmental policies enable our continued compliance with the relevant environmental obligations and the mitigation of negative impacts on the environment. Our Environmental Management System (EMS), is ISO 14001:2015 certified and covers 100% of our occupied UK corporate real estate, including the KRBS branch network.

Climate transition plan

The Group published its inaugural Climate Transition Plan in 2024 and in 2025 set about its implementation against a challenging external backdrop of continued uncertainty on government policy and support for housing decarbonisation and increased criticism and scepticism of net zero initiatives. In October 2025 the United Nations Finance Initiative - Net Zero Banking Alliance, of which OSB Group had been a member since 2023, ceased its operations as a member led initiative, following the exit of number of large financial institutions. We remain committed to embedding climate change considerations and management across our business, to ensure we remain resilient to the impacts and mitigate, where possible, our impact, through direct action and support for our customers.

Our Climate Transition Plan prioritises areas where we believe over time, and with the right support, tangible value can be delivered to stakeholders. The five pillars of action outlined in the Plan (see across) represent a responsible and proportionate strategy, focusing on supporting customers and real economy decarbonisation, footprint reduction and climate risk management. Our strategy recognises the scale and complexity of the challenge, and our dependence on external stakeholders such as customers, technology and government.

We previously reported our intention to release an updated version of the Plan in 2027. Following government and regulator consultations in 2025 and the release of the International Financial Reporting Standards Foundation transition plans guidance, we will review the timeline in early 2026 to ensure our disclosures continue to reflect best practice and remain relevant and useful to report users.

Find out more about our Climate Transition Plan.

Energy policy

The Group is committed to responsible energy use, compliance with applicable legislation, and continual improvement in energy performance. We prioritise low and zero carbon energy sources where feasible and recognise energy efficiency as a key enabler of our wider environmental and climate commitments. Our approach is informed by the Paris Climate Agreement and our commitment to the Science Based Targets initiative (SBTi). The Group aims to achieve net-zero value chain greenhouse gas emissions by no later than 2050.

The Policy applies to all locations under our operational control and is supported by our Environmental Management System, energy performance monitoring, and carbon reduction programmes. We also expect our suppliers and partners to demonstrate responsible energy practices aligned with our sustainability objectives. Governance and accountability for the Policy sit with senior management, with all employees expected to act in an energy-conscious manner.

Environmental policy

The Environmental Policy outlines the Group’s principles, commitments and governance approach for managing environmental impacts across its operations. It provides a framework for environmental protection, regulatory compliance, performance improvement and accountability, aligned with the Group’s sustainability and climate objectives.

The Policy is approved by senior management and the Board and reflects OSB Group’s commitment to environmental stewardship beyond statutory requirements. We are committed to protecting the environment, reducing our environmental footprint and supporting the global transition to a low-carbon economy.

The Group is dedicated to consulting and engaging with stakeholders on environmental matters while fostering awareness across the organisation. We actively promote responsible behaviours and embed environmental considerations into our business planning and decision-making processes.

The Group is committed to implementing and maintaining a robust Environmental Management System (EMS) to monitor, measure, and continually enhance environmental performance. Our priorities include reducing greenhouse gas emissions, and waste; improving the efficient use of energy and natural resources; and preventing environmental harm.

Guided by the Paris Climate Agreement and our commitment to the Science Based Targets initiative (SBTi), OSB Group aims to achieve net zero value chain greenhouse gas emissions by 2050 at the latest. We are committed to using 100% renewable energy wherever feasible and to maintaining our policy of refraining from financing or investing in the fossil fuel industry.

We also place strong emphasis on transparency, with regular reporting on our environmental performance and progress against our climate related commitments.

Governance and Responsibilities

Senior management is responsible for ensuring appropriate resources, capability and oversight are in place to deliver this Policy. Leaders and managers are accountable for embedding environmental commitments into business planning and operations, while all employees are expected to act responsibly and comply with supporting policies and procedures.

Reducing the emissions from OSB group buildings

The Group has committed to sourcing 100% of electricity from renewable sources where it has operational control. The electricity purchased comes from renewable tariffs supported by Renewable Energy Guarantees of Origin (REGO). The Group continues to prioritise the use of REGO-backed tariffs, ensuring minimal Market-based emissions are reported under Scope 2 Purchased Electricity.

Our transition to net zero operation emissions by 2030 continues with significant progress in Scope 1 and Scope 2 emissions Operational emissions in 2025 have reduced by 57% compare to 2024 and reduced 71% from our 2022 baseline.

Notable achievements include the installation of a new air source heat pump at one of our Chatham offices, as well as the disposal of three offices no longer in use as a result of consolidation programmes. This means all but one of our offices and branches are heated and powered by electric heating solutions.

• Direct Operations – Reduce Scope 1 and Scope 2 emissions to net zero by 2030 from a 2022 baseline. (Scope 2 emissions are calculated using Market-Based methodology).

Find out about our Direct Operations

Reducing the emissions from our mortgage lending

The Group continues to measure the emissions from our mortgage lending portfolio using the Partnership for Carbon Accounting Financials (PCAF) methodology.

Approximately 97% of our total emissions stem from financed emissions, which arise from the properties we finance. These emissions are a key focus of our climate strategy.

In 2025 we reviewed the ongoing suitability of the financed emissions target. We looked at the scenario that underpins the target, the methodology, and the data used to calculate the baseline and report performance. The review has resulted in the Group restating baseline financed emissions for 2022 which are 301,331.30 tCO2e.

The previous baseline contained erroneous data taken from the EPC public register that overstated property level emissions. This was identified and corrected for 2023’s reporting onwards. By restating the baseline we provide a more accurate representation of emissions and progress.

The Group’s financed emissions target is to reduce the emissions intensity (kgCO2 e/m2) of our mortgage lending by 25% by 2030 from a 2022 baseline. To achieve this the Group are reliant on a number of external dependencies for progress, including energy grid decarbonisation, pace of retrofitting, heat pump roll out, government policy, education and cost.

Find out about our Intermediate Finance Emissions Targets

Connecting our customers

In 2025, the Group funded a customer Energy Performance Certificate (EPC) pilot programme working with a third-party property data specialist. Several Buy-to-Let customers had the opportunity to find out more about the energy efficiency of their properties through assessments. We were seeking to understand what data and insight landlords found most useful, beyond what is available within the existing standard EPC, given its limitations, and where, as a specialist lender we can support and add value. Using a third-party tool, we analysed 10,000 Buy-to-Let properties, synthesising property specific energy-efficiency data sets and optimised action plans, showing cost effective routes to achieving an EPC rating of C. We offered participating landlords access to the reports and insights specific to their portfolios. Larger landlords fed back that they were aware of pending regulations and had plans in place to manage their portfolios. We are working with medium and smaller landlords to determine the use cases for the data and insight we have made available to them.

Providing customers with transition friendly products

We continued to offer products to support energy efficiency in property refurbishments for our Buy-to-Let customers under the Precise brand, however, uptake remains limited with just 32 applications in 2025. Through our InterBay brand, we offer a commercial product with reduced rates for properties with an Energy Performance Certificate (EPC) rating of C or higher, with completions totalling £287.2m in the year. Within the Group’s transformation programme, lending platforms have been designed to allow greater flexibility in energy-efficiency specific products. We recognise the importance of providing customers with supportive financing options for energy-efficiency and retrofit works in order to deliver progress towards our 2030 interim target. We expect that as landlords respond to increased requirements under the Minimum Energy Efficiency Standards, there will be increased interest in funding for retrofit works.

Scope 3 emissions

The Group account for its Scope 3 emissions as part of our environmental sustainability efforts. Scope 3 emissions refer to indirect emissions that occur in the value chain, outside of the company’s direct control. Annually, the Group undertakes a materiality assessment to determine which of the 15 categories within Scope 3 are relevant to us. Relevance is determined based upon: size (contribution to total emissions); degree of influence the Group has; the risk presented by the emissions; stakeholder interest; whether the service is outsourced; and sector specific guidance. The Group continues to review and evolve this process in line with the latest information.

To date the relevant scope 3 categories are Category 1 Purchased Goods and Services, Category 2 Capital Goods, Category 3 Fuel and Energy Related Activities, Category 5 Waste, Category 6 Business travel, Category 7 Employee commuting, Category 8 Upstream leased assets and Category 15 Investment (Financed Emissions).

Staff transportation impact reduction

To help reduce unnecessary travel related emissions, we support remote collaboration through telephone, video, and web conferencing, minimising the need for physical meetings and travel. Where travel is necessary, we encourage the use of low-emission or environmentally friendlier vehicles. These efforts reflect our commitment to embedding sustainability into our workplace culture and reducing our overall carbon footprint.

Waste management approach

The Groups waste management approach is part of its broader environmental commitment to sustainability and responsible operations. The Group aims to minimise waste generation across its sites and prioritises reuse, recycling, and recovery wherever possible. To ensure compliance, the Group installed new recycling and food waste stations across our offices and branch locations. An education programme was launched to guide colleagues through these changes. In 2025, we generated 212 tonnes of total waste (2024: 259 tonnes).

Our operational processes do not generate hazardous waste or pollutants beyond those typically found in an office environment. All hazardous waste, such as batteries and electrical equipment, is stored and disposed of in accordance with UK regulations. The Group also tracks waste metrics to monitor performance and drive continuous improvement.