Do I Need Existing and Proposed Floor Plans for Planning Permission?
Whether you need floor plans for planning permission depends on what you are applying for, the size and type of the project, and whether it falls under Permitted Development. Here is how the requirement works.
The short answer
Most planning applications for home extensions and alterations require existing and proposed floor plans as part of the submission. They help the council understand what is there now and what is being proposed. However, some smaller projects under Permitted Development do not require a full planning application, and therefore do not require formal floor plans.
When floor plans are required
A full planning application for a home extension, alteration or change of use normally requires existing and proposed floor plans at a standard scale — usually 1:100 or 1:50. The plans show the current layout and the proposed layout, including any walls, doors, windows, stairs and room uses. They are a standard part of the application forms and validation requirements for most local authorities in England.
When you may not need formal floor plans
If your project falls under Permitted Development — such as a single-storey rear extension within the permitted limits — you may not need a planning application at all, and therefore may not need formal floor plans submitted to the council. However, you still need to be sure the project is within the Permitted Development limits, and a breach of those limits can result in enforcement action requiring removal of the work.
What floor plans show that photos cannot
Photos show the current condition of a property but not the precise dimensions, layout relationships, or how the proposed changes fit within the existing structure. Floor plans give the council and any structural engineer a precise basis for assessing the work. They also help builders understand the scope and help avoid expensive mistakes on site.
Existing vs proposed plans
Existing floor plans show what is there now. Proposed floor plans show what will be there after the work is completed. The difference between the two — the delta — is what the council is assessing. For a simple wall removal, the existing plan shows the wall and the proposed plan shows the opening. For an extension, the existing plan shows the current footprint and the proposed plan shows the new footprint.
When to get the plans done
For a planning application, existing and proposed floor plans are typically needed at the point of submission. For a project that is still at the idea stage, a rough sketch is enough to explore the options. The plans become important when the design is being finalised, when the planning application is being prepared, or when builder prices are being sought.
Written by the PlanBuildCo team
9 years designing extensions and renovations in Poole, Dorset.
Ready to take the next step?
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