What is Building Regulations Approval? When You Need It and How to Apply
Building Regulations approval is separate from planning permission and applies to the technical standards your building work must meet. This guide explains when it is required and how the process works.
Published: 16 Mar 2026 · Updated: 16 Mar 2026 · 6 min read
Planning Permission vs Building Regulations, What Is the Difference?
Planning permission is concerned with whether development is acceptable in principle, its use, appearance, and impact on the surrounding area. Building Regulations approval is entirely separate: it governs how the building work is carried out to ensure the structure is safe, energy efficient, accessible, and fit for purpose.
You may need planning permission, Building Regulations approval, both, or neither, depending on the nature of the work. It is common for homeowners to confuse the two or to assume that because planning permission is not required, Building Regulations do not apply, this is incorrect.
When Building Regulations Approval Is Required
Building Regulations approval is required for:
| Type of work | Building Regs required? |
|---|---|
| Extensions (any size) | Yes |
| Loft conversions | Yes |
| Garage conversions to habitable space | Yes |
| New structural openings (e.g. removing a wall) | Yes |
| New bathroom or kitchen installation | Usually (drainage and ventilation) |
| Re-roofing (more than 25% of roof area) | Yes |
| Installation of a new boiler | Yes (Part J/L) |
| New electrics (new circuits, consumer units) | Yes (Part P) |
| Internal decoration and like-for-like repairs | No |
| Installation of cavity wall or loft insulation | No (exempt) |
The Technical Standards, The Approved Documents
The Building Regulations 2010 (as amended) set out the legal requirements. Compliance with the detailed technical guidance is demonstrated by following the Approved Documents (Parts A to S), published by MHCLG. Each part covers a specific area:
- **Part A**, Structure
- **Part B**, Fire safety
- **Part C**, Moisture resistance
- **Part F**, Ventilation
- **Part L**, Conservation of fuel and power (energy efficiency)
- **Part M**, Access and use
- **Part P**, Electrical safety in dwellings
How to Apply
There are two main routes to Building Regulations approval for domestic work:
Full Plans Application
You submit detailed drawings and specifications to the local authority Building Control department (or a private Approved Inspector / Registered Building Control Approver) before work begins. The plans are checked and approved in advance, giving certainty that the proposed work will comply. A site inspection is carried out during construction. On completion, a **completion certificate** is issued.
This is the recommended route for significant works such as extensions, loft conversions, and structural alterations.
Building Notice
For smaller works, a Building Notice can be submitted without full plans. Work can begin 48 hours after submitting the notice. The inspector checks compliance during construction. Note: a completion certificate may not always be issued under this route, and building notices are not suitable for all types of work.
The Completion Certificate
The completion certificate is the most important document produced by the Building Regulations process. It confirms that the completed works have been inspected and comply with the Building Regulations in force at the time.
Mortgage lenders and buyers will require the completion certificate when you sell. Without it, you may need to obtain retrospective indemnity insurance, which adds cost and complexity to the sale.
Property Passport UK allows you to store completion certificates, approved plans, and other Building Control correspondence against your property record, ensuring they are never lost and are immediately available when you sell or remortgage.
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