Building Notice vs Full Plans Application

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) at least 48 hours before work begins; a registered building control approver (RBCA, formerly an approved inspector) cannot accept a building notice, because the RBCA route runs on an initial notice given jointly by you and the RBCA to the local authority.¹² No plans are submitted for checking or approval (an extension needs only a 1:1250 site plan with the notice), instead, the building control officer inspects at key stages and raises any concerns on site.³

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

When to Use a Building Notice

Building notices work well for:

• Simple domestic projects where the building regulations requirements are well understood: a simple rooflight loft conversion in a traditional cut-timber roof, 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.⁴ For genuine emergency repairs you can start first and give the building notice as soon as reasonably practicable afterwards.⁵
• 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 a building the Regulatory Reform (Fire Safety) Order 2005 applies to, or will apply to once the work is done, which takes in buildings containing flats (dwellings above other dwellings), HMOs (houses in multiple occupation) and most commercial premises⁵
• Erecting a building that fronts onto a private street⁵
• Work to which requirement H4 applies: building over, or close enough to interfere with, a drain or sewer shown on the map of sewers⁵

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 is often sufficient, but some solicitors ask 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), check the provider’s requirements before choosing a route, as some expect a full plans approval

Fees in England and Wales

Building control fees are set by individual local authorities for LABC applications.⁶ Fees vary by authority, a single-storey rear extension might be about £900 at one council and £1,200 at another once the inspection charge is included. Many councils list the plan charge and the inspection charge separately: Crawley, for example, charges £308 to check the plans for a loft conversion of up to 40 m² and £560 for the inspections, so check that a quoted figure covers both.⁷ Most authorities publish fee calculators online. Registered building control approvers (RBCAs) set their own fees commercially and may be cheaper or more expensive depending on the project and their workload.⁶

Do not assume a building notice is the cheaper route: the site inspections are the same either way, and some councils charge more for a building notice. Crawley, for example, charges £924 for a building notice on a loft conversion of up to 40 m², against £868 for full plans.⁷ Check your council’s fee schedule.

The Process Step by Step

Building notice route:

1. Submit building notice form (online or paper) to LABC at least 48 hours before starting (if you use an RBCA, they give the local authority an initial notice instead)⁶
2. Pay the fee
3. Begin work and notify building control when you reach each stage it has asked to inspect, such as foundations, damp proof course, structural steel, drainage and insulation. The council sets those stages in writing, choosing the ones it intends to inspect according to risk.¹ Within five days of finishing, tell building control the work is complete.¹
4. Receive a completion certificate once all inspections are passed

Full plans route:

1. Prepare and submit drawings, calculations, and specification, usually done by an architect, structural engineer, or specialist designer
2. Building control checks the submission within 5 weeks (or a longer period if the applicant agrees in writing)⁴
3. Receive conditional or full approval, respond to any conditions before work begins
4. Carry out work and notify building control at each stage inspection
5. Receive a completion certificate

Regularisation (Retrospective Approval)

If work was carried out on or after 11 November 1985 without a building notice or full plans application, you can apply for a regularisation certificate retrospectively.⁸ 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 usually higher than for a normal application: Crawley, for example, charges £1,155 to regularise a loft conversion of up to 40 m², against £868 for full plans.⁷ Regularisation cannot be used by an RBCA, it must go through the local authority.⁸

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 that need approval, such as a new bathroom with fresh drainage, a building notice is practical and cost-effective, and a new boiler fitted by an installer registered with a competent person scheme needs no application at all.⁹ 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.