Short Abstract

Evaluation of the UK Public Sector Decarbonisation Scheme shows how evidence shaped policy and delivery, using mixed methods and adaptive feedback loops. Findings highlight barriers, context, and strategies for influencing decisions in dynamic net zero programmes.

Description

The UK’s Public Sector Decarbonisation Scheme (PSDS) represents a flagship investment in reducing carbon emissions across public buildings, aiming to accelerate progress toward net zero targets. This evaluation examines how evidence from PSDS has influenced policy and programme design, the barriers encountered in translating findings into decision-making, and the adaptive strategies that emerged in response to a dynamic delivery context.

Our mixed-methods evaluation explored implementation across diverse local authorities, schools, health trusts and other public sector bodies, focusing on the interplay between technical feasibility, organisational capacity, and funding mechanisms. Findings revealed that while the scheme catalysed significant carbon savings and innovation in heat decarbonisation, systemic challenges—such as compressed delivery timelines, supply chain constraints, and variable readiness among public bodies—limited the scale of impact. Context proved critical: organisations with strong energy management capacity leveraged the scheme effectively, while others struggled to navigate technical and procurement complexities, underscoring the need for differentiated support models. These insights prompted iterative changes to the policy, including adjustments to eligibility criteria, options for extended timelines, and enhanced guidance for applicants, demonstrating how evaluation can shape programme evolution in real time.

However, influencing policy was not without barriers. Competing priorities, fiscal pressures, and the urgency of climate commitments underscored the challenge of balancing vision with feasibility. Our evaluation highlights the importance of framing evaluation evidence in ways that resonate with decision-makers—emphasising cost-effectiveness, risk mitigation, and co-benefits such as improved building performance.

The evaluation adopted a mixed-methods design combining quantitative analysis of project-level data (including a quasi-experimental analysis of carbon savings) with qualitative insights from over 100 stakeholder interviews and case studies. A theory-based approach underpinned the evaluation, mapping causal pathways from funding inputs to decarbonisation outcomes. Rapid feedback loops were embedded through interim reporting and stakeholder workshops, enabling adaptive learning and informing programme adjustments during implementation. This approach ensured that evidence was both rigorous and timely, supporting decision-making in a fast-moving policy environment.

The evaluation illustrates the value of adaptive approaches in uncertain policy contexts. Rapid feedback and stakeholder engagement helped the programme navigate uncertainties such as inflation and technology availability. These strategies not only improved delivery but informed future rounds of PSDS and wider decarbonisation policy, embedding lessons on flexibility and resilience.

This case study offers practical insights for evaluators and policymakers working in complex, high-stakes domains. It demonstrates that evaluation is most influential when it moves beyond retrospective assessment to become an integral part of programme governance—providing timely, actionable intelligence that bridges the gap between evidence and decision-making. By reflecting on what worked, what did not, and why, this evaluation contributes to a deeper understanding of how evidence can drive adaptive, context-sensitive policy change in pursuit of net zero.

This will be a joint presentation between GC Insight as evaluators and the Department for Energy Security and Net Zero as the client.