Summary
- Scotland’s new direction makes an EIA mandatory for proposed data centres with more than 50MW of available electrical capacity.
- The rule takes effect on 17 September, while projects below the threshold remain subject to case-by-case screening.
- The measure follows an August direction requiring councils to notify ministers of data centre applications above the same threshold.
The Scottish Government will require an environmental impact assessment for every proposed data centre exceeding 50MW of electrical capacity, introducing a fixed national threshold for large developments from 17 September.
The Town and Country Planning (Environmental Impact Assessment) (Data Centres exceeding 50MW Power Capacity) (Scotland) Direction 2026 means projects above the threshold will automatically be treated as EIA development rather than relying on case-by-case screening to determine whether a full assessment is required.
The direction defines power capacity as the total proposed electrical power available to the data centre. Developments below 50MW will remain subject to the existing EIA regulations, under which planning authorities consider whether their likely environmental effects justify a full assessment.
The measure follows a separate direction introduced in August requiring planning authorities to notify Scottish ministers within seven days when validating applications for new data centres above 50MW. That notification requirement also applies to qualifying applications already under consideration.
DataCentral has previously reported on ministers requiring an EIA for a proposed data centre development in Fife. The new direction turns environmental assessment into a nationwide requirement for every new project above the threshold rather than an intervention applied to individual schemes.
A fixed trigger for large projects
The 50MW threshold gives developers and planning authorities a clearer test at the start of the development process. A qualifying project will now enter planning with the knowledge that an environmental report must form part of the application, affecting the amount of survey, design, and assessment work required before a decision can be reached.
An EIA does not determine whether planning permission should ultimately be granted. It requires the likely significant environmental effects of a proposal to be identified and assessed so that they can be considered alongside other planning factors.
The Scottish Government identified energy consumption, water use, construction and operational greenhouse gas emissions, biodiversity, soils, noise, landscape effects, and air quality among the potential issues associated with large data centres. Backup generators can add a further emissions and air-quality consideration where fossil-fuelled plant forms part of the resilience design.
Those impacts will differ substantially by project. Cooling architecture, generation mix, grid connection, site location, building form, backup-power strategy, and local environmental sensitivity all influence the eventual assessment.
The direction therefore creates a common requirement without prescribing one technical outcome. Developers will still need to demonstrate the effects of the particular electrical, mechanical, and construction systems proposed for each site.
Planning scrutiny moves earlier
Scotland’s approach places more of the environmental work at the front of the development process. The government said identifying the requirement for an EIA early gives developers greater scope to build mitigation into site selection and design and could reduce the risk of environmental issues causing delay later.
That comes as large data centre proposals place growing pressure on planning authorities to consider issues extending well beyond the buildings themselves. A 50MW-plus facility can require substantial grid infrastructure, backup plant, cooling equipment, construction activity, and associated utility works, while its effect on electricity demand can extend beyond the immediate planning boundary.
The threshold also makes the electrical scale of a scheme a more explicit planning parameter. Data centre projects are frequently described through floor area, rack count, or campus size, but the direction makes proposed available power the legal trigger for mandatory assessment.
The government said the rule will be reviewed periodically as technology and evidence develop. That leaves scope for future changes as rack densities, cooling systems, power architectures, and the environmental evidence around large digital infrastructure evolve.
For projects entering the Scottish planning system from 17 September, the immediate position is now clearer. Facilities above 50MW face mandatory environmental assessment alongside the existing ministerial notification requirement, adding another defined planning step before large blocks of proposed data centre capacity can move towards construction.
