Building Control Explained: Approval Routes, Inspections, and Completion Certificates

**What the Building Regulations 2010 cover**:

The Building Regulations 2010 (as amended) set out the minimum standards that new buildings and alterations to existing buildings must meet. They are organised into 'Approved Documents' (Parts A through S), each covering a different aspect of building performance:

• •*Part A — Structure*: Structural stability and robustness; load-bearing capacity; resistance to wind and ground movement
• •*Part B — Fire safety*: Fire spread; means of escape; access for firefighting; structural fire resistance; cavity barriers
• •*Part C — Site preparation and resistance to moisture*: Subsoil drainage; ground moisture resistance; weather resistance of walls and roofs
• •*Part E — Resistance to sound*: Airborne and impact sound insulation between rooms and between dwellings
• •*Part F — Ventilation*: Minimum ventilation rates; extract fans in kitchens and bathrooms; whole-house ventilation
• •*Part L — Conservation of fuel and power*: Thermal insulation of new elements; U-value requirements for extensions and loft conversions; energy efficiency of new windows and doors; boiler efficiency standards
• •*Part M — Access to and use of buildings*: Accessibility requirements for new dwellings and significant extensions
• •*Part P — Electrical safety in dwellings*: Competent person self-certification for electrical installation work; notification to Building Control
• •*Part Q — Security*: Minimum security standards for doors and windows in new dwellings and extensions

**When Building Regulations apply**:

Most significant building works require Building Regulations approval. Key triggers for domestic projects:

☐ Any extension (regardless of size, if it adds floor area to the dwelling) ☐ Loft conversions creating habitable rooms ☐ Garage conversions to habitable use ☐ Structural alterations (removing or altering load-bearing walls, installing structural steels) ☐ Basement conversions ☐ Installing or replacing a boiler, heating system, or hot water cylinder (Part J and Part L) ☐ New electrical circuits or rewiring (Part P — self-certification by registered electrician, or third-party Building Control notification) ☐ Installing a new window or door (Part Q — self-certification by FENSA or CERTASS registered installer, or third-party Building Control notification) ☐ Cavity wall insulation, external wall insulation, or loft insulation above certain thresholds (Part L)

**When Building Regulations do NOT typically apply**:

• •Like-for-like repairs and maintenance (replacing tiles, painting, replacing plasterboard, repairing a roof with the same materials)
• •Small outbuildings (under 30m² floor area, used for non-habitable purposes, no sleeping accommodation, not within 1m of a boundary — see Part 1, Class E of the GPDO 2015 PD rights, but note these are two separate regimes)
• •Internal alterations that do not affect structure, fire safety, energy efficiency, or drainage (removing non-load-bearing partition walls — but check Part B implications for means of escape)

*When uncertain*: Contact the Building Control body (Local Authority BC or an Approved Inspector) for a pre-application discussion — most offer this free of charge.

**Route 1 — Full Plans Application**:

• Under the Full Plans route, you submit detailed drawings (typically prepared by an architect or technician) and supporting calculations (typically from a structural engineer where structural work is involved) to the Building Control body BEFORE work starts. The Building Control surveyor reviews the submission and either:
• •Approves the plans (issues a Full Plans Approval notice) — work can proceed
• •Issues a conditional approval with specific requirements (e.g., additional structural calculations required)
• •Rejects the plans with reasons — plans must be amended and resubmitted

• *Advantages of Full Plans*:
• •Design issues are identified and resolved before work starts — not mid-construction
• •Approved plans provide certainty for the contractor, avoiding on-site rework
• •Provides a clear technical specification for tendering purposes
• •If the approved plans change during construction, a 'Regularisation' or 'Amendment to Full Plans' can be submitted
• •Gives buyers' solicitors and mortgage lenders the clearest evidence of Building Regulations compliance

*Timescales*: Plan checking: 5 weeks (local authority BC) or typically 3–4 weeks (Approved Inspector). Work can start on site immediately after submitting a Full Plans application (before approval is given) at the applicant's own risk — most contractors prefer to wait for approval on structural matters.

*Fee*: Calculated by the Building Control body; typically £400–£1,500 for a domestic extension; includes all site inspections to practical completion and the issue of a completion certificate.

*Best for*: Extensions, loft conversions, structural alterations, basement conversions, garage conversions — any project where design is fixed before starting.

**Route 2 — Building Notice**:

Under the Building Notice route, you notify the Building Control body that you intend to start works (at least 2 days before starting), but no detailed plans are submitted for checking. Instead, the Building Control surveyor inspects the works at key stages as they progress and advises on compliance.

• *Advantages of Building Notice*:
• •No delay waiting for plan approval — work can start in 2 days
• •Simpler administration — no need to prepare full working drawings before starting

• *Disadvantages of Building Notice*:
• •No pre-construction design review — compliance issues are identified on site
• •If the BC surveyor requires changes on site (different structural solution, additional fire protection), rework costs fall on the contractor and ultimately the homeowner
• •No approved plans document — buyers' solicitors may request further evidence; some mortgage lenders prefer Full Plans approval
• •NOT suitable for work subject to Section 1 of the Regulatory Reform (Fire Safety) Order 2005, work in HMOs, or work to flats

*Fee*: Similar to Full Plans, but typically slightly lower.

*Best for*: Minor or straightforward works where a professional contractor is experienced in the Building Regulations requirements and the design is simple. NOT recommended for structural work, loft conversions, or HMO works.

**Approved Inspectors vs. Local Authority Building Control**:

• Building Control services can be provided by either:
• •*Local Authority Building Control (LABC)*: The Building Control team of the local council. Always available; fees are set by the local authority; well-known to local planning and structural engineers.
• •*Approved Inspectors (private sector)*: Independent Building Control bodies (e.g., NHBC Building Control, Bureau Veritas, Quadrant, etc.). Often faster plan review; competitive fees; same statutory powers as LABC. Must notify the LABC of their appointment (Initial Notice — the LABC has a right to reject the appointment in certain circumstances).

For most domestic projects, either route works well. Approved Inspectors can offer faster turnaround and sometimes more flexible scheduling of inspections.

**Key Building Control inspection stages**:

Regardless of the approval route, the Building Control surveyor must be notified to carry out inspections at key stages. Typical inspection stages for an extension or loft conversion:

1. *Commencement*: Notification that works have started (for Building Notice route, this is the initial 2-day notice; for Full Plans, a separate commencement notice) 2. *Excavation*: Before the concrete is poured — foundations must be inspected at this stage; if concrete is poured before inspection, the BC surveyor may require it to be broken out 3. *Concrete/oversite*: After the concrete foundation and oversite are laid; before the ground floor is constructed above 4. *DPC*: Damp-proof course inspection at the base of the external wall 5. *Frame*: Structural frame inspection (floor joists, roof structure, steel beam installation) before it is covered 6. *Insulation*: Confirmation that thermal insulation meets Part L requirements (U-values, continuity, no cold bridges) 7. *Drains*: Foul drain connections, fall, access provision, and test before backfilling 8. *Fire protection*: FD30S doors, protected staircase, fire-stopping to penetrations, intumescent seals — particularly critical for loft conversions 9. *Completion*: Final inspection of the completed works

Missed inspections are a serious problem — particularly the foundation inspection. If the BC surveyor cannot inspect a stage because it has been covered up, they have the right to require opening up (at the contractor's cost, ultimately at the homeowner's cost).

**The completion certificate**:

After the final inspection, the Building Control body issues a Completion Certificate confirming that the inspected works comply with the Building Regulations. This is one of the most important documents in a domestic project:

• •*Required on sale*: Buyers' solicitors routinely require a copy of the Building Regulations completion certificate (and for energy-related works, a copy of the Part L compliance calculation) for any significant works carried out since the property was built
• •*Required for mortgage applications*: Lenders may require a completion certificate as a condition of releasing funds on a purchase
• •*Required for HMO licensing*: Many councils require copies of Building Control completion certificates for notifiable works as part of the HMO licence application
• •*Evidence for insurance claims*: In the event of a fire, flood, or structural failure, compliance certificates demonstrate that the works met statutory standards at time of construction

**What happens if works are carried out without Building Control**:

Unauthorised works (works that required Building Control approval but did not have it) are a serious problem:

• •*Regularisation*: The homeowner can apply for retrospective approval — a 'Regularisation Certificate' — but the BC surveyor may require opening up of completed works to verify compliance. This can be costly and disruptive.
• •*Enforcement*: The local authority has 12 months from the date of infringement to issue an enforcement notice (for most Building Regulations contraventions). After 12 months, enforcement by the LA is time-barred, but the works remain without a certificate.
• •*Indemnity insurance*: For historic unauthorised works (typically more than 12 months old with no enforcement action), buyers' solicitors often accept an indemnity insurance policy in lieu of a completion certificate. However, this is not available where the works are recent or where there is an existing enforcement notice.