Full Plans Building Regulations Application: Process and Inspections

A full plans building regulations application is the formal route to getting your design approved against the Building Regulations 2010 before you start building in England. You send detailed drawings, structural calculations, and written specifications to a building control body, which reviews them and issues a written decision.¹ It’s the approval route that gives the most certainty, because compliance problems get caught on paper rather than in finished concrete. For some buildings it’s the only legal choice; for others, it’s the sensible one.

When You Must Use Full Plans

Most building work in England needs building regulations approval, and you can usually pick between a Full Plans application and a simpler Building Notice. Regulation 12 of the Building Regulations 2010 takes that choice away in three situations, and Full Plans becomes compulsory.²

The building is (or will be, once the work is finished) covered by the Regulatory Reform (Fire Safety) Order 2005. That captures most non-domestic buildings, including offices, shops, schools, restaurants, hotels, and blocks of flats with shared areas.³
The new building fronts a private street rather than a publicly maintained highway.
The work is being built near or over a public sewer.

Outside those categories, Full Plans is optional but common on larger or complex projects. Approved plans lock in the design before construction spending climbs, and if a dispute emerges later you have a written approval to point to. A Building Notice never produces that document.

Building regulations are devolved across the UK. This route is for England; Wales, Scotland, and Northern Ireland run their own systems.

Full Plans or Building Notice?

A Building Notice is the stripped-down alternative. You send in a form and a fee without detailed plans, and building control inspects the work as it progresses.⁴ For a bathroom refit or a straightforward ground-floor extension, that can be enough. The risk is that nobody checks the design in advance, so a problem raised on site can mean tearing out finished work.

Full Plans gives you a formal written decision before you start: full approval, conditional approval, or rejection. Anything that touches structure, fire safety, or drainage is worth putting through the Full Plans route even when the regulations don’t require it.

A separate track exists for certain installation work under approved competent person schemes, where a registered tradesperson self-certifies compliance and notifies the local authority without any application from you. That’s outside the scope of Full Plans and only applies to the specific work types listed in Schedule 3 of the Regulations.⁵

What to Include in the Application

The whole point of Full Plans is that the building control body reviews your design in detail, so an incomplete submission gets sent back. You’ll typically need:

Architectural drawings — floor plans, elevations, and cross-sections at scales like 1:50 or 1:100, showing internal layout, external appearance, and how structural components fit together.
Structural calculations prepared by a qualified structural engineer, showing the building can carry the loads it will face.
Written specifications for materials and their performance ratings, including insulation thickness, glazing performance, and heating efficiency to satisfy Part L of the Building Regulations.⁶
A block plan showing the building’s position relative to property boundaries, neighbouring structures, and existing drainage.
Fire safety details for buildings covered by the Fire Safety Order — escape routes, compartmentation, fire detection, and alarm systems.
Evidence that ventilation and sound insulation meet the relevant requirements.

The application form asks for the building’s intended use, the site address, and a description of the proposed work. You can submit through the Planning Portal or directly to your local authority’s building control team.¹ Including manufacturer data sheets for key products such as fire doors, insulation boards, and boilers helps speed the review, because the assessor can verify British Standards compliance without chasing you.

Fees

Full Plans fees come in two parts. The Plan Charge is paid when you deposit your plans and covers the review of your drawings and calculations. The Inspection Charge covers site visits during construction and usually becomes due after the first inspection.

The amount depends on the type and scale of the project. A single-storey domestic extension costs considerably less than a new commercial building. Each local authority publishes its own fee schedule, so there’s no single national price list. Domestic extensions commonly run to a few hundred pounds for each charge; larger or commercial projects can reach several thousand. Check your specific council’s building control page, or use a fee calculator on the Planning Portal, before budgeting.

The Decision and How Long It Takes

Once you submit a complete application, the building control body checks your plans against every relevant part of the Building Regulations 2010.⁷ The statutory decision period is five weeks from the date of deposit. You and the authority can agree in writing to extend that to two months, which often happens on complex projects.

You’ll get one of three outcomes:

Full approval. Your plans meet all requirements and you can build as designed.
Conditional approval. The plans are broadly acceptable, but specific modifications or further details are needed before certain stages of work can start.
Rejection. The plans don’t comply. You’ll receive written reasons and can revise and resubmit, usually without a fresh Plan Charge.

A rejection is not the end of the road. Finding a fire safety shortfall in a set of drawings costs time; finding one mid-build costs money.

How Long Approval Lasts

Approval isn’t indefinite. If work hasn’t commenced within three years of your application being submitted, the approval lapses automatically, and a fresh application would be assessed against whichever version of the regulations is then in force.⁸

“Commenced” has a specific technical meaning that depends on what you’re building. For most homes and horizontal extensions, work counts as commenced when the entire sub-surface structure is complete: foundations, any basement level, and the ground floor structure. For more complex buildings (those on shared foundations, with more than one underground storey, or public buildings holding 100 or more visitors), commencement means completing the foundations and the structure of the lowest floor level. For other types of building work, 15% of the proposed work must be finished.⁸ Digging a trench and walking away won’t keep the approval alive.

After Approval: Inspections and Completion

Approval is the first step, not the last. Once construction begins, building control stays involved through site inspections to check that the actual work matches the approved design.

Before you start, give the building control body at least two working days’ notice of your intention to begin work.⁹ For higher-risk buildings overseen by the Building Safety Regulator, the notice period is five working days. You must also notify building control within five days after the work satisfies the definition of commencement.

The authority then decides which stages of the build it wants to inspect, based on a risk assessment.⁹ Common inspection points are foundation excavations, damp-proof courses, structural steelwork, drainage runs before they’re covered, and insulation before plastering. You’ll be told in writing which stages need notification and how long the work must remain visible before being covered up. Miss a notification and an inspector who can’t see the drainage because it’s already buried can require it to be dug up.

Notify building control within five days of completion. If the authority is satisfied that the work complies, it issues a Completion Certificate within eight weeks of receiving that notice.¹⁰ That certificate is your proof the work meets legal standards. Solicitors acting for buyers routinely request it during conveyancing, and its absence can stall or kill a sale. Mortgage lenders and insurers look for it too.⁴

What Happens If You Skip the Process

Building without approval, or building in a way that doesn’t match approved plans, is a criminal offence under Section 35 of the Building Act 1984.¹¹ The Building Safety Act 2022 significantly toughened the penalties.¹² In the Magistrates’ Court, conviction can bring imprisonment, an unlimited fine, or both. In the Crown Court, the sentence rises to up to two years’ imprisonment, an unlimited fine, or both. For a continuing offence, a further fine of up to £200 per day can apply for each day the breach continues after conviction.

There is no time limit on prosecution for building regulation offences.¹³ Work done a decade ago without approval can still lead to charges.

Building control also has a separate enforcement power under Section 36 of the Building Act 1984. It can serve notice requiring the owner to pull down non-compliant work or alter it to comply, and this notice can be issued up to ten years after the work was completed. If the owner doesn’t comply within 28 days (or a longer period granted by a court), the authority can carry out the work itself and recover the costs.¹⁴

If work has already been done without approval, whether by you or by a previous owner, you can apply to the local authority for a regularisation certificate under Regulation 18 of the Building Regulations 2010.¹⁵ Regularisation doesn’t shield you from prosecution, but it can resolve the compliance status of the building for conveyancing and insurance. You’ll submit a written application describing the unauthorised work, along with plans and any remedial work needed to bring it up to standard. Expect the authority to require opening up parts of the building — lifting floorboards, removing plasterboard, exposing drainage — so it can see what was actually built. Regularisation fees are typically higher than standard Full Plans fees, and the certificate isn’t guaranteed. If the authority can’t satisfy itself that the work meets, or can be brought to meet, the regulations that applied when the work was originally done, no certificate will issue.

1
Planning Portal. Full Plans
2
Legislation.gov.uk. The Building Regulations 2010 – Regulation 12
3
Legislation.gov.uk. The Regulatory Reform (Fire Safety) Order 2005
4
GOV.UK. Building Regulations Approval – How to Apply
5
Legislation.gov.uk. The Building Regulations 2010 – Schedule 3
6
GOV.UK. Conservation of Fuel and Power – Approved Document L
7
Legislation.gov.uk. The Building Regulations 2010
8
GOV.UK. Circular Letter – Changes to the Building Control Process
9
Legislation.gov.uk. The Building Regulations 2010 – Regulation 16
10
Legislation.gov.uk. The Building Regulations 2010 – Regulation 17
11
Legislation.gov.uk. Building Act 1984 – Section 35
12
Legislation.gov.uk. Building Safety Act 2022
13
Planning Portal. Failure to Comply With the Building Regulations
14
Legislation.gov.uk. Building Act 1984 – Section 36
15
Legislation.gov.uk. The Building Regulations 2010 – Regulation 18