The short version
- Find the application on your council’s planning website and note the deadline for comments.
- Read the water, energy, noise and environmental documents — or check whether they are missing.
- Put your questions in writing, to the planning officer and your councillors, and keep copies.
- If information is not published, ask for it formally through WhatDoTheyKnow. It is free.
- Get free, independent advice from Planning Aid (details below).
Step by step
Find out what is proposed
Search your local council’s online planning register for the site address or the words “data centre”. Proposals can also appear first in local news, in a developer’s leaflet or public exhibition, or in government announcements such as “AI Growth Zones”. Your town or community council is usually consulted on applications in its area, so ask them too.
Work out what stage it has reached
Is it still an idea, a formal pre-application consultation, a submitted application, a decision, or an appeal? The timeline on the home page shows why this matters: the earlier you engage, the more can still change. In Wales, developers of major schemes must consult the community before they submit an application — that is often your first real chance.
Read the key documents
Look for: the planning statement; the design and access statement; any water, energy or drainage statements; noise and air-quality reports; and, above all, whether an Environmental Impact Assessment (EIA) is being carried out. Councils decide early whether a full EIA is needed through a “screening opinion” — it is worth checking what was decided and why. Our plain guide to EIA explains what to look for. If a document you would expect is missing, that is itself a question to ask.
Ask your questions in writing
Email the planning officer named on the application and your local councillors. Be specific and polite, and keep a copy. Each issue page has questions drafted in full that you can copy, adapt and send. You can also write to your Member of the Senedd or MP, and to the relevant government minister.
If the information isn’t published, ask for it formally
Public bodies must answer requests under the Freedom of Information Act and, for anything about the environment, the Environmental Information Regulations — normally within 20 working days. The easiest way is WhatDoTheyKnow, a free service that sends your request and publishes the reply so others can see it too. Water companies are covered by the Environmental Information Regulations.
Comment formally, and on time
Planning comments count most when they deal with “material planning considerations”: impacts on water, traffic, noise, landscape, ecology, the local economy and so on. General objections to AI or to a company do not carry weight on their own. Check the deadline on the notice — it is often three weeks — and send comments in writing.
Get free advice
Planning Aid Wales and Planning Aid England give free, independent help to individuals and community groups on how to respond to planning applications.
Keep going after the decision
Permission usually comes with conditions — on noise, water, generators and so on. Ask who will monitor them and how the results will be published. Ministers can sometimes “call in” an application and decide it themselves. In August 2026 the Welsh Government issued a holding direction on a proposed data centre in Cardiff while it considered whether to do so.
Which questions should I ask?
Start with the two issues most people feel first:
Water
How much on the hottest day of a drought, and who is cut off first?
Power and the grid
Who pays for the grid upgrades, and what else waits in the queue?
Or use the fifteen-question checklist to test the whole proposal.
A word of caution
This page is general information to help you take part in the planning process. It is not legal advice about any particular case. If you are considering a legal challenge, time limits are short and you should take professional advice promptly.