Topic 13

Building regulations and building control

Understand building regulations, your building control options, applications, inspections and completion documents.

42 articles

The basics

01What are building regulations, and does my project need approval?Building regulations set standards for the safety, health, accessibility and energy performance of building work. Extensions, loft conversions, structural alterations and many service installations need compliance and an appropriate approval or certification route, even when planning permission is unnecessary.02Which works are exempt from building regulations?Some building work is exempt, and some repairs do not need a building control application. However, an exemption depends on the precise building and work; planning permission, electrical safety and other requirements may still need separate attention.03Who is responsible for compliance: me, the builder or the designer?Compliance is a shared legal responsibility: clients must arrange and support compliant work, designers must address compliance in their design, and contractors must carry out compliant work. Building control checks the project but does not take those responsibilities away.04Your duties as a client: principal designer and principal contractor under the Building Safety ActThe building regulations dutyholder regime requires suitable arrangements and competent people to plan, design and build compliant work. Principal designer and principal contractor roles are not limited to high-rise projects, and they are distinct from the similarly named construction health-and-safety roles.

Council or private building control?

05Council building control vs a private registered building control approver: which should I choose?For most non-higher-risk work, you can choose the council or a registered building control approver. Compare competence, the proposed checking and inspection service, communication, fees and continuity; neither route removes your duty to deliver compliant work.06Choosing council or private building controlCompare the service commitments, availability and technical support offered by council and private building control for your project. Neither route is automatically faster; assess the actual provider and proposal.07Comparing building control feesThere is no single building control price for a London project, and the cheaper route cannot be identified without comparable quotations. Compare the total charge for the same scope, including plan checking, inspections, amendments and completion, rather than the first payment alone.08How to check that an inspector is registeredCheck both the building control organisation and the individual inspector using the Building Safety Regulator’s official registers. A private company’s registration as an approver and a person’s registration as an inspector are different checks; neither should be inferred from a logo or job title.09What happens if my private approver stops trading?Contact the council promptly and establish the status of the private approver’s initial notice. Depending on the circumstances, the work may transfer formally to another registered building control approver or revert to the council; it cannot simply continue under an informal replacement appointment.10Can I switch building control body during the project?Switching building control body can be possible, but the available route depends on whether work has started and on the status of the existing application or initial notice. Obtain agreement on the formal transfer, cancellation or reversion procedure before ending the current appointment.

Applications

11Full plans or building notice?Full plans provide a formal check of detailed drawings before construction; a building notice is a more limited route without the same formal plan approval. A building notice is not available for every project, so establish eligibility before choosing it for convenience or speed.12What building regulations drawings includeBuilding regulations drawings explain how the project will be constructed to meet the applicable technical requirements. They normally need coordinated construction details, specifications and relevant calculations, rather than only the layout and appearance shown in planning drawings.13Plan checks and approval subject to requirementsA full plans decision can approve the design, approve it subject to specified requirements, or reject it. Since the October 2023 procedural changes, the current council terminology is approval subject to “requirements”, even though older documents and conversations may refer to “conditions”.14The initial notice: starting with a private approverAn initial notice is the formal notice used to place eligible work under a registered building control approver rather than ordinary council building control. It is submitted jointly with the person intending to carry out the work, and its acceptance is not the same as technical approval of the plans.15Commencement notices, and when an approval lapsesNotifying building control that work will start, reaching statutory “commencement”, and completing the project are three different events. For ordinary non-higher-risk work, the post-October 2023 rules include separate start and commencement notifications, and an approval or notice can lapse if the defined commencement threshold is not reached in time.16How long does building regulations approval take?A council full plans application normally has a five-week decision period, extendable to two months by agreement. A building notice, a private initial notice and BSR approval follow different procedures, so there is no single approval timescale that applies to every route.

Inspections and sign-off

17Inspection stages for an extension, a loft conversion and a basementBuilding control inspects selected stages when important work can still be seen, followed by completion. The exact schedule depends on the project, so agree it before starting rather than relying on one universal list for extensions, lofts and basements.18Who books the inspections?The person carrying out the work must ensure the required building control notifications and inspections are arranged. In practice the builder may make the bookings, but the client should agree this explicitly and check that the responsibility is not being left to the designer or inspector by assumption.19Work covered up before inspection: what now?Contact building control before concealing any more work and explain exactly what has been covered. The inspector will decide what evidence is needed; photographs or certificates may help, but opening up or testing can be required and should not be assumed avoidable.20The completion certificate: why it mattersThe final building control document records statutory sign-off of the completed work: a council normally issues a completion certificate, while a private approver uses a final certificate. Keep it with the property records because a planning approval or an approved drawing set does not replace it.21Compliance declarations at the end of the jobCompletion declarations are statements from the relevant dutyholders confirming their responsibilities and compliance position at the end of the work. They are part of the completion process and do not replace inspections, test results or installation certificates.22What happens if work is never signed off?Work without final building control sign-off can leave unresolved compliance questions and cause problems when the property is sold. The next step depends on whether an application or initial notice already exists, whether the work is compliant, and what evidence is missing.

Self-certified work

23Competent person schemes: electrics, windows, gas, heat pumps and solarAn authorised competent person scheme lets a suitably registered installer self-certify specified work and notify building control through the scheme. The registration must cover the actual installation; it is not a general approval for all work by that company, and Gas Safe registration has a separate legal basis.24My installer isn't registered with a scheme: what now?An installer’s lack of competent person scheme membership does not always make the work unlawful, but notifiable work still needs a valid building control route. Establish that route before work starts; for gas work, the separate requirement to use an appropriately Gas Safe registered business must not be bypassed.

Drains, sewers and Thames Water

25Is there a public sewer under my extension? Sewer maps and CCTV surveysCheck sewer records early, then verify the actual drainage layout where it affects the extension. A sewer map is useful evidence but may not show every relevant pipe; Thames Water advises that a builder or drainage specialist can survey the location and size of sewers and drains on the property.26Build-over agreements: when you need one, cost and timescaleWhere Thames Water is the sewerage provider, relevant work to an existing property within three metres of a public sewer or one metre of a public lateral drain normally needs its build-over process. The fee and overall programme depend on the sewer and application class; the published 21-day technical review is not a guaranteed end-to-end approval period.27Manholes inside an extensionIf a public-sewer manhole lies within the proposed extension, Thames Water requires it to be relocated rather than left inside the building. A sealed internal cover is not a substitute for that requirement; agree the revised drainage and access arrangement before fixing the extension design.28Can a public sewer be diverted?A public sewer can sometimes be diverted, but its owner must assess and agree the proposal. Where Thames Water owns the sewer, use its diversion process rather than moving the pipe as an ordinary private drainage alteration; feasibility, land rights, design and cost need resolving before construction.29Rainwater: soakaways and sustainable drainageRainwater drainage should use the appropriate sustainable route rather than automatically connecting a new roof or driveway to the nearest sewer. Building regulations prioritise infiltration where practicable, then a watercourse, with sewer discharge considered where the earlier options are not reasonably practicable.

The technical requirements

30StructureThe structural requirements concern whether the building can safely carry its loads and remain stable. For an extension, loft or structural alteration, the design must account for the new work, the existing building and the ground, not just the size of an individual beam.31Fire safetyFire safety under building regulations concerns warning, escape, resistance to fire spread, structural fire performance and fire-service access. The appropriate solution depends on the building and the work: an ordinary house extension, a loft conversion and alterations to a block of flats need different assessments.32Ventilation and trickle ventsVentilation must provide suitable fresh air and remove pollutants and moisture; replacement windows should not leave the home with worse ventilation. Trickle vents are one way of providing background ventilation, but the correct approach depends on the existing and proposed ventilation system.33Energy efficiency: insulation, U-values, SAP and limits on glazingEnergy compliance depends on the type of work: new homes, extensions, replacement elements and renovated existing elements are not assessed identically. U-values describe heat loss through construction, while calculations and limits on openings address the performance of the wider design.34OverheatingPart O requires overheating risk to be addressed in new residential buildings within its scope. It does not automatically apply to every extension or loft conversion, but summer comfort still needs to be considered alongside glazing, ventilation and any relevant planning requirements.35Sound insulationPart E addresses resistance to sound, including separation between homes and relevant internal walls and floors. New-build dwellings and dwellings formed by a material change of use have different performance criteria, so the construction and testing strategy should be chosen for the actual project.36Stairs, headroom and guardingStairs must be designed for safe use, adequate headroom and suitable protection at open edges. The guidance differs between private stairs inside a home and common or other access stairs, so a domestic loft detail should not be copied into a shared stair serving several flats.37DrainageBuilding regulations require suitable arrangements for foul drainage, wastewater and rainwater, including access for maintenance. The design must identify where each system goes and how new work affects existing drains and public sewers; a convenient nearby pipe is not automatically a suitable connection.38AccessPart M addresses access to and use of buildings, with different guidance for dwellings and other buildings. For homes, establish whether the project must meet M4(1), M4(2) or M4(3); the applicable requirement depends on the work and any valid planning condition, not simply the owner’s present needs.39Electrical safetyPart P requires electrical installations in dwellings to be designed and installed safely, whether or not the particular work is notifiable. New circuits, consumer-unit replacement and specified work in special locations have notification requirements; agree the competent installation and certification route before work starts.40Water efficiencyFor new dwellings within the relevant Part G scope, the current calculated water-consumption limit is 125 litres per person per day. A lower 110-litre limit applies where the optional requirement is imposed through planning; proposed tighter standards should not be treated as current law.41EV chargingPart S requires electric-vehicle charging infrastructure for specified new buildings, changes of use and major renovations with associated parking. It does not mean that every extension or loft conversion needs a charger, and the detailed requirement depends on the building, parking and applicable exceptions.42SecurityPart Q addresses resistance to unauthorised access in new dwellings within its scope, focusing on doors and accessible windows. Compliance concerns the complete door or window assembly and its installation, not simply buying a lock described as high security.