When work requires Building Regulations approval in England and Wales, you must notify the relevant building control body before work begins. There are two principal routes for most domestic projects: the building notice and the full plans application. Choosing correctly matters — the wrong route can leave you without the documentation needed when you sell or insure the property, or expose you to costly remedial work if an inspector raises concerns mid-build.
A third option, a regularisation certificate, applies retrospectively to work that was carried out without consent — covered briefly at the end.
The Core Difference
A building notice is a simple declaration that work is about to start. You submit it to the local authority building control (LABC) or an approved inspector (now called a registered building control approver, RBCA) at least 48 hours before work begins. No plans are submitted for checking or approval — instead, the building control officer inspects at key stages and raises any concerns on site.
A full plans application submits detailed drawings and a specification for checking before work begins. Once approved, you receive a stamped set of plans confirming the design meets the Building Regulations. Work can then proceed against those approved plans, with stage inspections confirming the build follows them.
Comparison Table
| Feature | Building Notice | Full Plans Application |
|---|---|---|
| Plans submitted for check | No | Yes |
| Approval decision required before work | No (48 hours notice only) | Yes (within 5 weeks, or 2 months with agreement) |
| Design certainty before starting | Low | High |
| Useful for straightforward/small works | Yes | Yes (overkill for minor works) |
| Useful for complex or large projects | Risky | Recommended |
| Accepted for HMOs, flats, commercial | No | Yes |
| Provides approved plans for sale/mortgage | No | Yes |
| Typical fee (domestic single-storey extension, plan check + inspections) | £900–£1,200 | £900–£1,400 |
| LABC fee structure | Fixed by local authority | Fixed by local authority |
| Approved inspector / RBCA fee | Market rate | Market rate |
When to Use a Building Notice
Building notices work well for:
- Simple domestic projects where the building regulations requirements are well understood: a loft conversion using a standard trussed rafter approach, a single-storey extension on a detached house, a new bathroom, or an internal partition removal.
- Projects where the contractor is very experienced with the relevant type of work and unlikely to deviate from accepted practice.
- Urgent repairs where waiting 5 weeks for full plans approval would cause further damage or disruption — for example, structural repairs following a flood.
- Where the client accepts the risk that the BCO may require changes on site, potentially adding cost.
A building notice cannot be used for:
- Work on buildings containing flats (dwellings above other dwellings)
- HMOs (houses in multiple occupation) and most commercial premises
- Work in a designated area where full plans are mandated by condition
- Projects subject to a fire safety engineer report requirement
When to Use Full Plans
Full plans approval is the safer, more expensive route and is recommended for:
- Extensions, loft conversions, and structural alterations of any significant complexity — where structural calculations, SAP energy assessments, or drainage design need checking before work begins
- Any project where you want certainty — the approved drawings provide a clear baseline and protect you if the BCO or an RBCA raises a dispute during construction
- Properties you intend to sell — mortgage lenders and conveyancers frequently ask for approved drawings, not just a completion certificate. A building notice completion certificate alone has been sufficient in the past, but solicitors are increasingly asking for the full package
- New-build and large-scale renovation — the formal checking process catches design errors before they become expensive construction errors
- Warranty schemes (NHBC, LABC Warranty) — most require full plans submission as a condition
Fees in England and Wales
Building control fees are set by individual local authorities for LABC applications. Fees vary by authority — a single-storey rear extension might be £900 at one council and £1,300 at another once the inspection charge is included; quotes under about £900 almost always exclude the inspection element. Most authorities publish fee calculators online. Approved inspectors (RBCAs) set their own fees commercially and may be cheaper or more expensive depending on the project and their workload.
| Project Type | Typical LABC Fee (Full Plans) |
|---|---|
| Single-storey extension (up to 40 m²) | £900–£1,200 |
| Two-storey extension | £1,000–£1,500 |
| Loft conversion | £1,000–£1,500 |
| New dwelling (single house) | £1,800–£3,000+ |
| Basement conversion | £1,200–£2,000 |
| Internal alteration (e.g. one RSJ beam) | £300–£600 |
Building notice fees are typically 50–75% of the full plans fee at most local authorities, reflecting the reduced checking work involved.
The Process Step by Step
Building notice route:
- Submit building notice form (online or paper) to LABC or an RBCA at least 48 hours before starting
- Pay the fee
- Begin work — inform building control at each inspection stage (foundations, damp proof course, structural steel, drainage, insulation, completion)
- Receive a completion certificate once all inspections are passed
Full plans route:
- Prepare and submit drawings, calculations, and specification — usually done by an architect, structural engineer, or specialist designer
- Building control checks the submission within 5 weeks (or 2 months if the applicant agrees)
- Receive conditional or full approval — respond to any conditions before work begins
- Carry out work and notify building control at each stage inspection
- Receive a completion certificate
Regularisation (Retrospective Approval)
If work was carried out after 11 November 1985 without a building notice or full plans application, you can apply for a regularisation certificate retrospectively. This involves an inspection of the completed work — sometimes requiring opening up floors, walls, or ceilings to expose structural or services elements. The fee is typically 1.25 to 1.5 times the normal full plans fee. Regularisation cannot be used by an RBCA — it must go through the local authority.
A regularisation certificate confirms that the building control officer was satisfied with the work at the time of inspection. It is not the same as a formal completion certificate under a live application and is treated differently by some mortgage lenders — worth checking with your conveyancer before relying on it.
Choosing the Right Route
For small, straightforward domestic jobs — fitting a new boiler, replacing a bathroom, taking out a non-structural wall — a building notice is practical and cost-effective. For anything involving structural work, a new dwelling, fire safety engineering, or a project you plan to sell or refinance, full plans is worth the additional cost and wait. The approved drawings and completion certificate together provide a robust paper trail that stands up to lender scrutiny and protects you against disputes with the contractor or subsequent owners.
If you are unsure, call the building control department at your local authority before submitting — they will advise on which route is appropriate and are generally helpful at the pre-application stage.
