Mastering the Prior Approval Process
The Prior Approval Process has become an increasingly popular route for homeowners and developers looking to extend or convert properties in the UK. By avoiding the lengthy full planning permission route, developers can streamline their projects significantly.
Introduced under the Town and Country Planning (General Permitted Development) Order 2015, this streamlined planning route allows certain types of development to proceed under Permitted Development Rights. However, this is strictly subject to the local planning authority approving specific aspects of the build. Understanding how this system works can save both time and capital, while ensuring your development remains fully compliant with UK regulations.
Unlike a full planning application, this streamlined route focuses solely on particular considerations such as the impact on neighbouring properties, design and external appearance, flood risks, and the preservation of natural light in habitable rooms.
When Do You Need to Navigate the Prior Approval Process?
You will likely need to engage with this framework for several specific types of residential and commercial projects:
1. Larger Home Extensions
If your planned extension exceeds the standard permitted development limits—such as deeper rear extensions—you will likely be required to submit an application. The local authority must consult with your immediate neighbours before granting permission.
2. Commercial to Residential Change of Use
Converting offices, high-street shops, or agricultural buildings into homes often falls under these specific rules. If you are planning an Office to Flats conversion or transforming Barns to Dwellings, checking your eligibility under these rights is a vital first step.
3. Additional Storeys and Complex Loft Conversions
Some upward extensions and loft developments require approval, particularly when adding significant height to the existing roofline.
The Core Benefits for Developers
Choosing to utilize this planning route offers several distinct advantages for your project timeline and budget:
Faster Decisions: Local authorities are typically required to reach a decision within 56 days.
Reduced Costs: Application fees are generally less expensive than those associated with full planning applications.
Targeted Scope: The assessment focuses only on key planning issues rather than a subjective review of the entire development.
However, it is important to note that permission is not guaranteed. Detailed supporting information and structural evidence are still strictly required.
Essential Documentation and Drawings
A successful application relies heavily on the quality of the information submitted. You will usually need to provide:
Existing and proposed architectural drawings.
Site location and detailed block plans.
A design and access statement (required in specific conservation scenarios).
Detailed daylight and sunlight assessments for conversions.
Comprehensive structural information.
For official statutory guidance on what constitutes Permitted Development and the associated limitations, you should consult the UK Government’s Planning Practice Guidance.
Why Structural Engineering is Vital in the Prior Approval Process
Although this is fundamentally a planning procedure, the physical execution of the project—especially loft conversions and heavy extensions—requires expert input from a structural engineer early in the timeline.
A qualified structural engineer from WeStruct will:
Assess Load-Bearing Elements: Before removing walls for a larger extension, we calculate how the loads will be redistributed.
Design Steelwork: We provide the necessary Beam Design and calculations required to support the new structure securely.
Ensure Building Regulations Compliance: Securing planning is only half the battle; the structure must still pass rigorous Building Regulations.
Evaluate Foundations: Upward extensions add significant weight to a property. We may recommend a Structural Inspection to determine if the existing foundations can handle the increased load.
Common Reasons for Refusal
Applications can still be rejected by the local authority. Common pitfalls include:
Proposals that negatively impact neighbouring amenity (such as overshadowing).
Inappropriate scale or poor external design matching.
Insufficient technical information provided in the initial submission.
Failure to meet the strict permitted development criteria limits.
Careful preparation and professional structural guidance significantly improve your chances of a first-time approval.
Comparing Your Options
Understanding the difference between the available planning routes is critical for project strategy.
| Aspect | Prior Approval Process | Full Planning Permission |
| Scope | Limited to specific technical considerations | Full subjective assessment of the entire project |
| Timeframe | Approximately 56 days | Usually 8 to 13 weeks |
| Cost | Lower application fees | Higher application fees |
| Flexibility | Highly restricted to set criteria | More flexible, open to negotiation |
If your project falls outside the strict permitted development rights limits, full planning permission will absolutely be required.
Final Thoughts on Your Development Strategy
The Prior Approval Process is a highly efficient route for many residential developments across the UK. However, success depends entirely on proper initial planning, accurate architectural drawings, and robust structural engineering.
Before committing capital to your next development, consult with the experienced architectural and structural professionals at WeStruct to guide you safely through the statutory process.