1. What is Permitted Development (PD)?
Permitted Development rights allow you to perform certain extensions and alterations without submitting a formal planning application, saving months of wait time.
- Single-Storey Rear Extensions: Can extend up to 3m from the original rear wall for terraced/semi houses, or 4m for detached houses.
- Larger Home Extension Scheme: Under prior approval, you can extend up to 6m (terraced/semi) or 8m (detached), provided neighbors do not object.
- Height Limits: Extensions must not exceed 4m in height, or 3m if within 2m of a boundary.
2. When Planning Permission is Mandatory
You will need to submit a formal planning application if your project falls outside PD limits, or if your property is subject to special restrictions:
- Conservation Areas, AONBs, or National Parks: Permitted Development is heavily restricted or removed.
- Listed Buildings: Any alteration (internal or external) requires Listed Building Consent.
- Flats and Maisonettes: flats do not have Permitted Development rights; you always need planning permission for extensions.
3. Building Regulations: Always Required
Do not confuse planning permission with Building Regulations. Even if your extension does not need planning permission, it MUST comply with Building Regulations. This covers foundations, insulation, ventilation, fire safety, and structural support.
Conclusion & Next Steps
To protect your investment, always apply for a Lawful Development Certificate (LDC) from your local council if building under Permitted Development. This provides legal proof that the extension was lawful at the time of construction.
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