Tiering of Environmental Assessment in spatial planning: Analysis of two case studies on and offshore

Emilia Ravn Boess (AAU), Jóhanna Sofia Guldbrandsø Nolsøe (AAU), Súsanna Rakul Foldbo Hjallnafoss (AAU), Tanja Kristensen (AAU), Lone Kørnøv (AAU)

This practice note investigates how the concept of tiering—where environmental assessments (EAs) at higher planning levels inform and streamline successive lower-level assessments—is implemented within spatial planning processes. It centers on two detailed case studies (one terrestrial, one offshore) to unpack how biodiversity considerations are carried through various planning stages.

Content & Structure:

• Context & Rationale: Introduces tiering methodologies in Environmental Assessment (EA), framing their significance in connected and multi-level planning workflows.
• Case Study Methodology: Details the selection of two spatial planning scenarios and outlines the tiering frameworks applied in each.
• Biodiversity Insight Flow: Evaluates how high-level biodiversity data and findings migrate through planning tiers.
• Comparative Analysis: Highlights differences in tiering efficacy between the onshore and offshore contexts, noting barriers and enabling factors.
• Conclusions & Recommendations: Summarizes key lessons and proposes practical guidance to reinforce biodiversity-sensitive planning via effective tiering.

Applications:

This resource is valuable for environmental planners, policy-makers, consultancies, and researchers engaged in spatial planning. It helps practitioners:

• Understand when and how to employ tiered EAs effectively.
• Improve coherence in biodiversity monitoring across planning scales.
• Implement best-practice recommendations to enhance policy alignment and environmental protection in multi-stage projects.

10.5281/zenodo.15607264