When To Apply For Building Control

Knowing when to apply for Building Control can save weeks of delay, prevent failed inspections and keep your project legally compliant. Building Regulations approval is separate from planning permission and focuses on how work is designed and constructed. Get the timing wrong and you risk having to open up finished work, pay for repeat inspections or, in extreme cases, undo non compliant construction.

This article primarily covers building control procedures in England under the Building Act 1984 and the Building Regulations 2010. Wales, Scotland and Northern Ireland have separate regulations, technical standards and application systems. A short summary for each nation appears below.

The guide sets out when to apply, which route to choose, typical costs and timelines, statutory notices, inspection preparation and the documents you should retain after completion.

What Building Control Is and Why Timing Matters

Building Control checks compliance with the Building Regulations, which cover structural safety, fire safety, energy efficiency, drainage, ventilation, electrical safety, sanitation and access. In England, the main legal framework sits under the Building Act 1984 and the Building Regulations 2010, as amended.

For most domestic projects, you can use a local authority building control service or appoint a private registered building control approver. Higher risk building work is handled through a separate Building Safety Regulator process.

Timing matters because approval is not just a paper exercise. Inspectors must see elements at the correct stage, such as foundation excavations before concrete is poured or insulation before plasterboard conceals it. If you miss those opportunities, Building Control may require trial holes, photographs, calculations or exposure work to verify compliance.

Building Control approval does not replace planning permission, listed building consent, Party Wall procedures, freeholder consent or restrictive covenant checks. Each regime has a different purpose and may follow a different timetable.

If you are unfamiliar with the technical scope, it is worth reviewing Understanding UK Building Regulations for Extensions before starting. It explains what parts of a build are regulated and why.

Geographical Scope Across the UK

The Full Plans and Building Notice procedures described in detail here apply to England. The other UK nations use their own systems.

• Wales. Building regulations are devolved to the Welsh Government. Local authorities provide building control services, while private building control work is subject to the registered approver regime. Check current Welsh guidance through Welsh Government building regulations.
• Scotland. Scotland uses building warrants rather than the English Full Plans and Building Notice routes. A building warrant normally needs to be granted before work starts. Guidance is available through Scottish Government building standards.
• Northern Ireland. Applications are made to the building control service at the relevant district council. Full Plans and Building Notice options are available, but the legislation, forms and procedures are specific to Northern Ireland. See Northern Ireland building regulations guidance.

If your property is outside England, confirm the correct route before commissioning technical drawings or starting work. Do not assume that English Approved Documents or notice periods apply elsewhere.

When To Apply For Building Control Approval

You should choose your building control provider and application route before any work on site begins. In practice, the ideal submission date depends on the complexity of the design, the construction programme and whether planning consent is also required.

Full Plans application, best for most projects

Apply once your drawings and core specifications are ready, typically after the architectural design and structural calculations are complete. This route involves submitting detailed plans for assessment before work starts. The local authority checks the information against the Building Regulations and relevant Approved Documents.

A proper Full Plans submission normally includes a completed application form, the correct fee, location plan, existing and proposed drawings, sections, construction details, structural calculations and relevant energy information. Drainage layouts, ventilation details and fire precautions may also be required.

Under the statutory procedure in England, a local authority generally has five weeks to determine a Full Plans application. This can be extended to two months where the applicant agrees. These are statutory decision periods, not guaranteed design review times.

In practice, an initial response may arrive sooner, especially for a clear domestic submission. Approval can take longer if drawings are incomplete, consultees are required or revised calculations must be supplied. Allowing five to eight weeks in the project programme remains sensible, but homeowners should distinguish that practical allowance from the formal determination period.

The authority may approve the plans, reject them or approve them subject to conditions where the legislation permits. Queries raised during the check should be answered by the designer or structural engineer before site work reaches the affected detail.

Use Full Plans for extensions, loft conversions, structural alterations, basement works and projects involving steelwork, unusual foundations or a complex fire strategy. It gives the client and contractor an agreed technical basis and reduces the risk of expensive decisions being made during construction.

Plan approval does not guarantee that the finished work will comply. The contractor must build in accordance with the approved information, and changes should be reported before they are covered up.

Building Notice, a quicker route for simpler jobs

In England, a Building Notice must generally be given to the local authority at least two working days before work starts. There is no formal approval of detailed plans before construction, so compliance is assessed through information requested during the work and through site inspections.

The submission usually requires an application form, fee, site location details and a description of the proposed work. The authority can ask for plans, structural calculations or other information where needed to assess compliance.

This route can suit straightforward internal works, small alterations and projects where an experienced designer and competent builder have resolved the construction details. It carries more risk because there is no approved set of plans confirming the proposed approach before work begins.

A Building Notice cannot be used for every project. Restrictions can apply where work relates to premises covered by fire safety consultation requirements, where a new building fronts a private street or where construction is proposed over or near a public sewer. Check eligibility with the local authority and the sewerage undertaker before relying on this route.

It is not usually the best choice for complex work, flats, substantial changes to fire separation or projects involving several designers. Party Wall matters are separate and do not determine whether a Building Notice can be used.

For a clear comparison, see Building Notice vs Full Plans Which Building Control Route Is Right for Your Renovation.

Regularisation, only if work has already been done

If unauthorised work was carried out on or after 11 November 1985, you may be able to apply for a Regularisation Certificate through the local authority. This is a retrospective route and is not available through a registered building control approver.

Expect intrusive inspections, exposure work and a higher fee. The authority may ask for walls, floors, drains, beams or foundations to be opened so hidden construction can be assessed. There is no guarantee that a certificate will be issued without remedial work.

Regularisation does not remove the physical consequences of defective construction. A structurally unsafe alteration, inadequate fire separation or poor insulation may still need substantial correction. Speak to the local authority before opening up work so the inspector can identify what evidence is required.

Application Information and Supporting Documents

A technically complete submission is easier to assess and less likely to hold up the start date. The exact requirements vary with the project, but an extension or loft conversion commonly needs the following:

• A location plan showing the property and site boundaries
• Existing and proposed floor plans, elevations and sections
• Foundation size, depth and construction details
• Structural calculations for beams, posts, lintels and padstones
• Wall, roof and floor build ups, including insulation thicknesses
• Drainage routes, inspection chambers and connection points
• Fire protection, escape and smoke alarm information
• Ventilation rates and extract fan provision
• Window, door and safety glazing specifications
• Energy calculations where required by Part L
• Details of accessible entrances, sanitary provision and circulation where relevant
• The names and contact details of the client, principal designer and principal contractor

Drawings should agree with the structural engineer’s information. A common source of delay is a beam shown in one position on the architectural plan and in another position on the engineering plan. Resolve clashes before submitting or ordering steel.

The application should also identify whether the work involves a building subject to the higher risk regime. Ordinary house extensions and loft conversions are not normally higher risk building work, but work to tall residential buildings may fall within the Building Safety Regulator’s remit.

Statutory Notices and Inspection Milestones

Submitting an application is only the first step. The client must make sure the required notices are given and that Building Control can inspect work before it is concealed.

For local authority controlled work in England, notice must generally be given at least two working days before the work starts. Under the amended regulations, the client must also notify the authority of the date on which work is treated as commenced. This commencement notice must be provided not more than five working days after commencement.

For larger projects, commencement has a defined legal meaning and is more than basic site preparation. For a new building, it generally requires work such as foundations and ground floor construction to reach the prescribed stage. For other building work, commencement depends on the project and whether a material operation forming part of the regulated work has started. Ask the building control body to confirm the relevant threshold where the programme is phased.

The client must also provide a completion notice within the required period, generally no later than five days after the work has been completed. This includes signed declarations from the client, principal designer and principal contractor confirming their appointments and duties. Supplying the notice does not itself certify compliance. Building Control must still be satisfied with the work and supporting evidence.

Site inspection arrangements vary between local authorities and registered building control approvers. Do not assume that every stage carries a universal 24 hour or 48 hour notice period. Some councils request notice by a stated time on the preceding working day, while others use online booking systems or agree stages directly with the surveyor.

Confirm the local procedure before starting. Common inspection points include:

• Commencement of the regulated work
• Foundation excavations, before concrete is poured
• Completed foundations where requested
• Oversite preparation, hardcore and damp proof membrane
• Dampproof course and ground floor construction
• Drainage installation before backfilling, plus testing
• Structural elements, including steels, floor structures and restraint straps
• Roof structure before insulation and finishes conceal it
• Thermal insulation and airtightness details before plasterboarding
• Fire protection to beams, floors, walls, doors and escape routes
• Completion, including testing, commissioning and certification

First fix electrical or plumbing work may be reviewed where it affects fire stopping, ventilation, drainage or the structure, but it is not a universal inspection stage on every domestic project.

A good builder will coordinate inspection requests and retain written records. The client should still check that visits happened and that any actions raised by the surveyor were closed before the work moved on.

Costs You Should Expect

Fees vary by council, project size and inspection requirements. Registered building control approvers set their own charges. Below is a realistic guide for domestic work in England.

Project type	Typical fee range	What it covers
Small internal alterations	£300 to £700	Plan check and inspections or Building Notice
Single storey extension up to 40m²	£500 to £1,200	Full Plans check and site inspections
Two storey extension	£900 to £1,800	More inspections and structural review
Loft conversion	£600 to £1,400	Fire and structure focused inspections
Regularisation application	25 to 50% higher than standard fees	Extra administration and intrusive checks

Check whether the quoted charge includes all anticipated site visits, plan assessment and VAT. Local authority charging schemes vary, while a private quotation may be based on the expected number of inspections. Design changes, repeated failed visits or work outside the original scope can attract additional charges.

Engineering calculations are separate. Structural engineer fees for beams and foundations typically range from £300 to £1,000 depending on complexity. Thermal calculations for energy compliance may add £150 to £400. More involved energy modelling, air testing or sound testing will cost more.

Allow a contingency for opening up and remedial work if the project starts before details have been resolved. Saving a few hundred pounds on drawings can lead to several thousand pounds of rework on site.

Typical Timelines From Design to Sign Off

Planning and Building Control often run in parallel but serve different purposes. A realistic programme for a standard extension might look like this:

• Design and surveys, 2 to 6 weeks
• Planning permission if required, normally 8 weeks for a householder application
• Structural design and technical details, 1 to 4 weeks
• Full Plans statutory decision period, normally 5 weeks or up to 2 months by agreement
• Practical allowance for resolving technical queries, commonly 5 to 8 weeks
• Construction, 8 to 16 weeks depending on size and complexity
• Final inspection and certificate, often within several days or weeks once all work and paperwork are satisfactory

A certificate is not guaranteed immediately after the last site visit. Missing electrical certificates, air test reports, drainage test results or dutyholder declarations can delay the file even where the visible construction is complete.

If you are preparing to start, a structured setup helps avoid delays. This checklist complements your application timeline, Pre Construction Checklist for UK Home Renovations Surveys Utilities Notifications and Site Setup to Avoid Costly Delays.

What Building Control Will Check on Site

Inspectors are not there to manage the project or supervise the builder. They inspect selected work to assess compliance. Responsibility for correct design and construction remains with the project dutyholders.

Expect close attention on these areas:

• Structure, foundation depth, bearing capacity, beam sizes, padstones and lateral restraint
• Fire safety, escape windows, protected stairways, fire doors, cavity barriers and smoke detection
• Thermal performance, U values for walls, roofs and floors, plus continuity of insulation
• Ventilation, background ventilation and extract rates in kitchens, utility rooms and bathrooms
• Drainage, falls, connections, access points, bedding and testing
• Electrical safety, Part P compliance and certification by a suitably competent installer
• Gas safety, works by registered engineers listed on Gas Safe Register
• Safety glazing, guarding, stair geometry and headroom
• Moisture resistance, weather protection and damp proofing
• Energy systems, controls, commissioning and provision of operating information

Official guidance is published by the UK Government in the Approved Documents. You can reference them here, Approved Documents.

Approved Documents give recognised methods of satisfying the regulations, but they are not the regulations themselves. Alternative solutions may be accepted if the designer demonstrates compliance with suitable evidence.

Full Plans vs Building Notice, a Practical Comparison

The choice affects when you apply and your risk profile on site.

Criteria	Full Plans	Building Notice
When to apply	Before work starts, with time allowed for the statutory decision and queries	At least 2 working days before starting
Upfront detail	Detailed drawings and specifications required	Less paperwork at submission, although information can be requested later
Certainty	Higher, as many issues are resolved on paper	Lower, as details may be assessed during construction
Best for	Extensions, lofts and structural works	Simple internal alterations
Risk of rework	Lower if approved details are followed	Higher if site details do not comply

Dutyholder Responsibilities

The amended Building Regulations introduced clearer dutyholder roles for building work in England. Legal responsibility does not sit solely with the homeowner or solely with the builder.

The dutyholder regime generally identifies the client, designers and contractors. Where more than one designer or contractor is involved, the client must appoint a principal designer and principal contractor in writing.

The client must make suitable arrangements for planning, managing and monitoring the work so that it complies with the Building Regulations. This includes allowing enough time and resources, appointing competent people, sharing relevant information and making sure the required notices are submitted.

A domestic client is a homeowner having work carried out for purposes not connected with a business. Some duties may be carried out on the domestic client’s behalf by the principal designer and principal contractor, but the homeowner should still confirm appointments, keep records and avoid instructing non compliant work.

Designers must ensure that their design work, if built, would comply with the Building Regulations. They must provide sufficient information to other dutyholders, consider information supplied by others and cooperate with the wider project team. A designer should not accept work beyond their competence.

The principal designer controls the design phase and coordinates design compliance. This role is different from merely preparing planning drawings. The principal designer must identify design gaps, coordinate specialist input and maintain relevant records.

Contractors must carry out work in accordance with the regulations and the agreed design. They must have the skills, knowledge, experience and behaviours needed for their work, or the organisational capability where a company is appointed.

The principal contractor coordinates the construction phase. This includes checking that site work follows the compliant design, managing changes, cooperating with designers and ensuring that information needed for completion is gathered.

All dutyholders must cooperate, communicate relevant information and refuse work they are not competent to undertake. Product substitutions and site changes should be recorded and assessed rather than agreed informally after the original detail becomes difficult to build.

Practical Checklist Before You Apply

• Measured survey and accurate existing drawings
• Proposed plans, sections and elevations with construction build ups
• Structural calculations for beams, lintels and foundations
• Site investigation for soil type if foundations are significant
• Drainage layout and proposed connections
• Thermal specifications to meet Part L
• Ventilation strategy for Part F
• Fire strategy for lofts and multi storey layouts under Part B
• Written appointment of the principal designer and principal contractor where required
• Confirmation that designers and contractors are competent for their roles
• Builder appointed or shortlisted so details are buildable
• Programme that allows for notices and inspections
• A system for retaining drawings, photographs, test results and change records

Work That May Be Exempt

Some small buildings and alterations can be exempt from Building Regulations, but the exemptions are subject to detailed conditions. Planning permission or listed building consent may still be required.

A detached single storey building with an internal floor area not exceeding 15m² is often exempt if it contains no sleeping accommodation. A detached building between 15m² and 30m² may also be exempt if it contains no sleeping accommodation and is either at least one metre from the boundary or constructed substantially from non combustible materials.

A porch or conservatory at ground level may be exempt where its internal floor area does not exceed 30m², the existing external entrance door remains in place and safety glazing requirements are met. Any new electrical installation must still comply with Part P. A conservatory with an open connection to the house or significant heating alterations may not qualify.

Certain repairs and replacements do not require a building control application. However, replacing windows, boilers, roof coverings or electrical installations can still be controlled work. Installers registered under an authorised competent person scheme may self certify eligible work and issue the relevant compliance certificate.

Removing a loadbearing wall, forming a new opening, converting a loft, altering drainage or changing the use of a building will commonly require approval. Ask the building control body for written confirmation if relying on an exemption.

Common Mistakes to Avoid

Starting work before the correct notice. Even with a Building Notice, you must submit the application, allow the statutory period and arrange inspections. Starting early risks enforcement action and missed inspection stages.

Assuming planning permission covers Building Regulations. They are separate. You can have planning consent and still fail Building Control.

Inadequate drawings. Vague plans lead to queries, conditions or rejection. Missing details on insulation, ventilation or fire protection often cause delays.

Skipping structural calculations. Steel sizes and padstones must be calculated. Guessing on site invites failure.

Missing inspection stages. Pouring foundations before inspection is a classic example. The inspector may require trial holes or exposure at your cost.

Changing approved details without review. Moving a beam, reducing insulation or changing a door specification can affect several parts of the regulations. Send material changes to the designer and Building Control before proceeding.

Non certified electrical and gas work. Use suitably qualified tradespeople and obtain the correct certificates. Without evidence of compliance, final certification may be delayed.

Poor record keeping. Keep photographs of key stages, delivery tickets for insulation, product data, marked drawings and test results. These records can resolve queries quickly.

What Can Go Wrong, Real World Examples

Under specification insulation. A rear extension built with insufficient wall insulation failed at the inspection before plastering. Sections had to be opened and additional insulated plasterboard installed, adding £1,200 and a week of delay.

Incorrect foundation depth. Clay soils near trees required deeper foundations than expected. Without approval at excavation stage, the builder poured at 750mm. The inspector later required substantial remedial work to sections, costing several thousand pounds.

Loft conversion fire strategy. Missing fire doors and inadequate escape provisions led to refusal at completion. Retrofitting doors, upgrading alarms and protecting the stair enclosure added cost and disruption.

Drainage fall issues. Poor falls prevented proper flow. Sections of the patio were lifted to correct pipe runs after a failed test.

Working With Your Builder and Inspector

Clear communication keeps everything moving. Agree early who will contact Building Control, provide notices and attend inspections. Many professional builders coordinate these tasks, but the client should verify that they have been completed.

Ask the contractor to provide at least several days of warning before an inspection point. This allows time to book the visit under the local service’s procedure. Do not let concrete, plasterboard, backfill or finishes be installed until the required inspection has taken place.

Invite the inspector to the agreed key stages rather than pushing for a single visit. If something is uncertain, ask for feedback before proceeding. Inspectors will not design the solution, but they can explain what evidence they need to assess compliance.

Keep a simple site diary. Record inspection dates, who attended, photographs taken and actions raised. Pair this with current drawings and written records of design changes. This becomes valuable if the surveyor changes, the contractor leaves or a query arises during a future sale.

Preparing for the Final Inspection

Book the final inspection only when the regulated work is substantially complete and safe to inspect. Rooms should be accessible, services should be commissioned and unfinished items should be limited.

Before the visit, check that stairs, guarding, smoke alarms, extract fans, fire doors, drainage access and safety glazing are complete. Confirm that insulation has been installed as designed and that all required fire stopping is in place around pipes, ducts, cables and structural steel.

Prepare a digital or paper completion pack. Give Building Control time to review specialist documents rather than sending them after the inspector arrives.

If the final visit identifies defects, ask for a written schedule. Agree which items require another inspection and which can be closed through photographs, certificates or revised drawings. Do not assume that a satisfactory verbal comment means the project has been certified.

From Inspection to Completion Documentation

At the end of the project, Building Control will carry out a final inspection and review the completion information. They may expect to see:

• Electrical installation certificate and any relevant Part P compliance notification
• Gas Safe documentation if gas work was carried out
• Commissioning certificates for boilers, heating controls and ventilation systems
• Glazing compliance, often through FENSA or CERTASS where eligible windows were replaced
• Air pressure or sound insulation test reports where required
• Drainage test results where requested
• Evidence of hidden insulation and fire stopping, including photographs
• Updated drawings and calculations for approved design changes
• The statutory completion notice and dutyholder declarations

Under the local authority route, the council can issue a Completion Certificate once it is satisfied that the completed work complies, based on the information and inspections available.

Under the registered building control approver route, the approver submits a Final Certificate to the local authority and provides the relevant parties with documentation. The Final Certificate is the key building control completion document for that route. It is not the same document as a local authority Completion Certificate.

Keep the application, approved or accepted drawings, decision notice, inspection correspondence, Completion Certificate or Final Certificate, structural calculations, warranties and all trade certificates. Store both digital and paper copies.

These records are commonly requested by conveyancers, buyers, surveyors and mortgage lenders. They also help future builders understand where beams, drains, insulation and concealed services were installed.

For a step by step explanation of passing final checks, see How to Get Building Control Sign Off in the UK for Home Renovations Inspections You Need, What to Prepare and Common Reasons for Failure.

Local Authority vs Registered Building Control Approver

For most domestic building work in England, you can use the local authority or appoint a private registered building control approver. Both assess work against the same Building Regulations, but the administration and completion documents differ.

Local authority teams are familiar with local ground conditions, drainage issues and housing types. Their fees follow the authority’s charging scheme. Surveyor availability and response times vary between councils.

A registered building control approver may offer flexible communication and continuity with a named surveyor. Fees are commercially quoted and can be higher or lower depending on project complexity and the expected inspection programme.

Under the building control regime introduced after 2023, private sector organisations performing building control functions must be registered as building control approvers. Building control professionals carrying out restricted activities and functions must also meet registration requirements as building inspectors.

For a private appointment, the client and registered building control approver submit an Initial Notice to the local authority. Work should not proceed under that private arrangement until the notice has been accepted or treated as accepted under the statutory process.

If the approver cannot continue, the Initial Notice may need to be cancelled and the work may revert to the local authority. This can require additional information, inspections and fees, so check the provider’s registration and terms before appointment.

Higher risk building work does not use the ordinary local authority or registered approver route. Applications for building control approval, changes and completion are made to the Building Safety Regulator under the separate regime.

FAQs

Do I need Building Control for non structural internal work?

Some internal work is exempt or outside the scope of an application, such as replacing certain fixtures on a like for like basis. However, changes to drainage, electrical installations, ventilation, fire safety or structure may require approval. Removing a non loadbearing wall can still affect fire separation, ventilation and escape routes. Ask Building Control before starting if the position is unclear.

Can my builder handle the application for me?

Yes, many builders submit Building Notices or coordinate Full Plans applications. However, duties are shared between the client, designers and contractors. Ensure the correct dutyholders are appointed, then obtain confirmation of submission, approved drawings where applicable, inspection records and final documentation.

What happens if I sell without completion documentation?

Buyers and lenders may flag missing certification. You could need to apply for Regularisation where available or provide indemnity insurance. Insurance does not correct unsafe or non compliant work and may not be available if the local authority has already been contacted. Missing documents can delay or disrupt a sale.

How far in advance should I book inspections?

Follow the notice procedure set by your local authority or registered building control approver. Requirements vary, so do not rely on a universal 24 hour or 48 hour rule. Agree the inspection stages and booking method at the start, then give as much warning as the construction programme allows.

Does a Building Notice save money?

Fees can be similar to Full Plans. Any initial saving can be lost through site changes or remedial work if details fail to comply. For anything beyond simple work, Full Plans often costs less overall because technical problems are identified before construction.

Does plan approval expire?

Building control applications can be affected if work does not commence within the relevant statutory period. For many applications in England, the authority may declare plans of no effect where work has not commenced within three years. Confirm the deadline shown on your decision notice, especially if planning or funding delays the project.

Can I change builder after work starts?

Yes, but update the dutyholder information and tell Building Control where required. Give the replacement contractor the approved drawings, inspection notes, calculations and change records. The incoming contractor should inspect unfinished work before accepting responsibility for the construction phase.

Final Thoughts

Apply for Building Control before you start, choose the correct route and plan notices and inspections as carefully as the build programme. Most problems arise from poor timing, unclear responsibility and missing information rather than unusually difficult regulations.

Get the drawings and calculations right, appoint competent dutyholders and keep a clear record of inspections and changes. At the end, retain the local authority Completion Certificate or registered building control approver Final Certificate alongside the technical and trade documents.

If you are ready to get started, post a job on BookaBuilderUK to receive free quotes from vetted local tradespeople who understand Building Control and how to pass it first time.