UK Planning Guidance
Modular planning permission delays projects more than construction
Modular buildings can simplify construction, but many UK projects slow down earlier — at the planning stage. Most delays come from avoidable assumptions or missing information, not the building method itself.
Key takeaway
Most modular delays happen before mobilisation — during validation, clarifications, and re-submission risk.
3 common UK planning mistakes (and how to avoid them)
Below are three common planning mistakes seen on UK modular projects, along with practical checks that reduce the risk of redesign or re-submission.
Mistake 1
Permitted development assumptions
Assuming a modular building is “permitted by default” can lead to rework. While some proposals may fall under permitted development, many still require full planning consent depending on use, size, siting, permanence and how the proposal relates to the existing site.
Common misconception
“Modular” describes the build method — it does not automatically determine whether permission is required.
How to avoid it
Check permitted development rules and confirm your planning permission requirements are aligned with the specific site and proposal (including constraints and prior conditions where relevant).
Planning officer lens
Submissions move faster when the proposal is described consistently across forms, drawings and supporting statements.
Mistake 2
Unclear planning drawings
Planning officers need clear, consistent information to assess impact and compliance — including elevations, materials, heights and site context. Generic layouts or marketing-led visuals can trigger requests for further information or refusal.
How to avoid it
Prepare planning-ready drawings showing key dimensions, finished height, external materials/colour, and how the building sits within the site. Where relevant, reference local validation guidance.
Mistake 3
Unreviewed site constraints
Site-specific constraints can affect what is acceptable and deliverable. Access, drainage, servicing routes, boundaries, neighbours, flood risk and local policies can all influence outcomes.
Early checks reduce rework
Checking constraints before the design is fixed reduces late changes that force updates to drawings and supporting documents.
How to avoid it
Review site constraints and access considerations before finalising the design, so the submission reflects practical realities and avoids late redesign.
