Non-Technical Summary
Scottish Infrastructure Strategy
AECOM has been commissioned to undertake a Strategic Environmental Assessment (SEA) in support of the emerging Scottish Infrastructure Strategy on behalf of the Scottish Government. This Environmental Report is the main output of the SEA process, following on from the Screening and Scoping Report consulted on in December 2025 and January 2026.
The Infrastructure Strategy will set out Scotland’s infrastructure priorities for the period 2027-2037, providing a 10‑year framework to guide infrastructure planning, investment, and delivery across the country. It will build on the work of the Infrastructure Commission for Scotland, the Infrastructure Investment Plan (2021-2026), the 30‑year Needs Assessment, and a range of national policy documents including National Planning Framework 4, the Place Principle, and the National Strategy for Economic Transformation.
The Infrastructure Strategy does not contain specific projects or proposals. Instead, it provides high‑level priorities and principles, shaping how future Spending Reviews and Budgets will align with climate, nature, economic and place‑based objectives.
What is Strategic Environmental Assessment?
Strategic Environmental Assessment (SEA) is a structured process for identifying, reporting and mitigating the environmental impacts of an emerging plan or strategy. It ensures environmental considerations are integrated into decision‑making at an early stage and helps identify potential significant effects, explore reasonable alternatives, and improve transparency.
This Environmental Report has been prepared in accordance with the Environmental Assessment (Scotland) Act 2005, which implemented European Directive 2001/42/EC.
This Environmental Report
This Environmental Report accompanies the draft Infrastructure Strategy for consultation. It presents:
- An overview of the stages undertaken to date for the SEA;
- An assessment of reasonable alternatives;
- An assessment of the draft Infrastructure Strategy;
- A proposed monitoring framework; and
- Next steps for the SEA process.
What is the Scope of the SEA?
In line with the 2005 Act, the Scottish Government consulted Historic Environment Scotland, SEPA, and NatureScot on the scope and level of detail to be included in the Environmental Report. A Screening and Scoping Report was issued via the SEA Gateway in December 2025.
Scoping identified a range of environmental topics that form the focus of the assessment:
- Air quality;
- Biodiversity, flora and fauna;
- Climatic factors;
- Cultural heritage;
- Landscape and geodiversity;
- Material assets;
- Population and human health;
- Soil; and
- Water.
These topics were translated into a set of SEA objectives forming the assessment framework (available in Chapter 4 in the main body of this report).
Appraisal of Reasonable Alternatives
Assessing ‘reasonable alternatives’ is a key requirement of the Strategic Environmental Assessment process, as set out in the Environmental Assessment (Scotland) Act 2005. The Act requires that the Environmental Report must identify, describe, and evaluate the likely significant environmental effects of both the proposed strategy and any reasonable alternatives.
For the Infrastructure Strategy, alternatives were developed around four strategic themes:
- Timescales and Sequencing;
- Infrastructure Investment Hierarchy;
- Environmental Ambition; and
- Role of a Place‑Based Approach.
The SEA evaluated how a range of options could lead to different environmental outcomes across the nine SEA topics.
Timescales and Sequencing
- Option T1: 5‑year Strategy
- Option T2: 10‑year Strategy
Option T2 performs more favourably across the SEA topics due to the longer planning horizon, better alignment with the 30‑year Needs Assessment, and greater certainty for sequencing investment. Option T1 performs less favourably due to reduced capacity to plan larger or long‑lead interventions.
Infrastructure Investment Hierarchy
- Option IH1: Strengthened ‘maintain and enhance first’ model
- Option IH2: Balanced approach
- Option IH3: Greater emphasis on new build
Option IH2 performs more favourably across the majority of SEA topics as it balances asset optimisation with flexibility for new development. Option IH1 performs favourably for several SEA topics where minimising land‑take and resource use is beneficial, while Option IH3 performs less favourably across many topics due to greater potential for construction‑related environmental effects.
Environmental Ambition
- Option E1: Highest environmental ambition
- Option E2: Minimal compliance
- Option E3: Balanced ambition
Option E1 performs more favourably across the majority of SEA topics due to stronger integration of environmental protection. Option E3 performs moderately across the topics, and Option E2 performs less favourably across many topics because it provides only baseline environmental safeguards. The highest level of environmental ambition (Option E1) performs best across almost all SEA topics.
Place‑Based Approach
- Option PB1: Strong place‑partnership model
- Option PB2: Nationally led approach
- Option PB3: Locally determined approach
Option PB1 performs more favourably across the majority of SEA topics because coordinated decision‑making supports more consistent environmental outcomes. Option PB2 performs moderately across the topics, while Option PB3 performs less favourably across several topics as wholly local approaches may lead to inconsistency across boundaries. A strong place‑partnership approach (Option PB1) performs best across all SEA topics, supporting coordinated and context‑sensitive decision‑making.
Preferred Approach for the Infrastructure Strategy
The preferred approach for the Infrastructure Strategy brings together a 10‑year strategic horizon, a balanced application of the Infrastructure Investment Hierarchy, a higher level of environmental ambition, and a strong place‑partnership model.
This approach seeks to maximise long‑term environmental, social, and economic outcomes while ensuring infrastructure investment remains fiscally responsible and aligned with the diverse needs of Scotland’s people and places.
Appraisal of the Draft Infrastructure Strategy
Chapter 6 of the Environmental Report presents the assessment of the draft Strategy against the SEA topics. Key findings are summarised below.
Air Quality
The Infrastructure Strategy is expected to result in mixed but broadly beneficial effects on air quality. Cleaner transport modes, reduced dependence on fossil‑fuel heating, increased use of green and blue infrastructure, and the prioritisation of existing assets all contribute to long-term significant beneficial effects. Moderate short term adverse effects are likely during construction and delivery phases of schemes and in areas experiencing cumulative major development.
Biodiversity, Flora and Fauna
The Infrastructure Strategy is likely to result in mixed effects on biodiversity, flora, and fauna. Significant long ‑term beneficial effects may arise from nature based solutions, expansion of green and blue infrastructure networks, reduced land‑take through asset optimisation, and ecological opportunities linked to place‑based regeneration. Adverse effects may occur in the short to medium term, primarily through construction disturbance, habitat loss, and potential cumulative pressures in areas targeted for substantial economic activity. The overall significance will depend on how well biodiversity considerations are embedded across programme development, spatial prioritisation, and investment governance.
Climatic Factors
The Infrastructure Strategy is anticipated to deliver significant long ‑term beneficial effects on climate change mitigation and adaptation. Significant long-term beneficial climate mitigation effects are expected from decarbonisation of heat, energy, and transport, and from reduced embodied emissions through asset optimisation. Significant beneficial adaptation outcomes are expected to be generally beneficial over the medium to long term, though the significance will depend on local siting, design, and coordination across sectors. Minor short ‑term adverse effects may arise from construction emissions and from increased energy demand associated with new industrial activity.
Cultural Heritage
The Infrastructure Strategy is expected to generate mixed effects on cultural heritage. Moderate beneficial long ‑term effects may arise from asset reuse, heritage‑led regeneration, and the alignment of infrastructure planning with place‑based principles. Potential significant adverse effects are most likely where construction and development pressures lead to disturbance of historic fabric, buried archaeology, or the setting of valued landscapes. A degree of uncertainty remains, with the overall significance depending on the strength of heritage‑sensitive design, early assessment, and appropriate mitigation across infrastructure programmes.
Landscape and Geodiversity
The Infrastructure Strategy is likely to lead to mixed effects on landscape and geodiversity. Significant long ‑term beneficial effects may arise from nature-based solutions, high‑quality regeneration, and reduced land‑take through asset reuse. However, long-term significant adverse effects may also arise, particularly where large‑scale energy or industrial infrastructure affects sensitive rural or coastal landscapes, or where construction disturbs geological features. The overall significance of effects will depend on spatial choices and the strength of landscape‑responsive design.
Material Assets
The Infrastructure Strategy is expected to have mixed effects on material assets. Significant beneficial long‑term effects are likely from reduced demand for primary minerals due to asset reuse, improved resource efficiency, and strengthened circular‑economy practices. Potential significant short to medium term adverse effects may arise from increased material demand associated with major infrastructure projects and from the generation of construction and demolition waste. The overall significance will depend on how effectively mineral safeguarding, waste‑minimisation measures, and circular‑economy principles are embedded across delivery programmes.
Population and Human Health
The Infrastructure Strategy is likely to have significant long-term beneficial effects on population and human health, particularly through improved access to services, enhanced local environments, reduced inequalities, and strengthened climate resilience. There remains some risk of short-term adverse effects, associated with construction disturbance, localised environmental pressures, or uneven distribution of economic development. Over time, benefits are expected to strengthen as place‑based approaches and regeneration programmes mature.
Soil
The Infrastructure Strategy is expected to have mixed effects in relation to soil. Long ‑term moderate beneficial effects are likely through asset reuse, brownfield regeneration, and nature‑based adaptation measures. While significant long-term adverse effects may occur primarily through soil disturbance, sealing, erosion, and peatland impacts associated with construction and land‑take. Cross‑boundary soil issues (especially relating to sediment movement and soil‑carbon loss) underscore the need for coordinated planning across catchments and regions. The overall effects will depend on the strength of mitigation and the degree to which soil considerations are embedded in project‑level decisions.
Water
The Infrastructure Strategy is likely to have mixed but broadly beneficial long ‑term effects on the water environment. Significant beneficial effects may result from nature‑based adaptation measures, improved drainage systems, catchment‑led approaches, and better alignment between strategic planning and water‑infrastructure investment. However, localised significant adverse effects may also arise through construction impacts, increased surface‑water runoff, pressures on wastewater systems, or risks to sensitive water bodies. Long‑term outcomes will depend on effective integration of water‑environment considerations across programme design and delivery.
Cumulative and In‑Combination Effects
Cumulative effects arising from the Infrastructure Strategy are expected to be mostly beneficial in the long term, with gains across several SEA topics. Localised adverse cumulative effects may arise where concentrated development occurs, including across environmental boundaries, but these are likely to be effectively managed through coordinated planning, embedded safeguards, and ongoing monitoring.
In‑combination effects are expected to be broadly beneficial where the Infrastructure Strategy works alongside other aligned plans, particularly in supporting climate resilience, biodiversity recovery, and sustainable place‑making. Adverse in ‑combination effects may occur in areas where overlapping programmes generate environmental pressures, including across ecological and hydrological boundaries, but these can be mitigated through joint planning, integrated assessments, and close coordination between national, regional, and local strategies.
Recommendations for Implementation
The Environmental Report identifies recommendations to support delivery of the Strategy, including:
- Strengthen references to air quality outcomes and air quality objectives;
- Acknowledge the climate and nature emergencies as drivers for decision‑making;
- Encourage whole‑life carbon assessments for major programmes;
- Promote Resource and Waste Plans and circular‑economy materials;
- Engage early with water and wastewater providers;
- Recognise opportunities to enhance the historic environment;
- Promote sensitive siting and design of major energy and industrial infrastructure; and
- Encourage catchment‑based approaches to water‑related infrastructure planning.
Recommendations are summarised in Chapter 6 of the Environmental Report.
Monitoring
Monitoring is an important part of the Strategic Environmental Assessment process. It helps track the environmental performance of the Infrastructure Strategy and ensures that the predicted effects occur as expected. It also allows for the identification of any unforeseen impacts, enabling timely action if needed.
The Environmental Report includes a proposed monitoring programme, which outlines how the implementation of the strategy will be tracked. This programme focuses on areas where significant environmental effects were identified and sets out:
- The environmental change or effect to be monitored;
- The relevant SEA topic;
- The indicator to be measured;
- The source of information and frequency of monitoring;
- The trigger for intervention if issues arise; and
For further detail, see the proposed monitoring programme in Chapter 7 of the Environmental Report.
Next Steps
This Environmental Report is being published alongside the draft Infrastructure Strategy for consultation. All comments received will be considered, and any changes to the Infrastructure Strategy will be assessed as required.
In accordance with Part 3 of the Environmental Assessment (Scotland) Act 2005, a Post Adoption Statement will be prepared and published once the strategy is adopted. This statement will explain:
- The reasons for choosing the preferred proposals in light of other reasonable alternatives;
- How environmental considerations were integrated into the proposals’ development process;
- How consultation responses were taken into account; and
- The measures decided for monitoring the significant effects of the proposals.
This ensures transparency and demonstrates how the SEA process has informed the final adopted strategy.
