Building Regulations Exemptions: Which Works Are Exempt and Which Are Notifiable

Quick Answer: Most building work in England requires Building Regulations approval, but Schedule 2 of the Building Regulations 2010 exempts specific categories (small detached buildings ≤15m² or ≤30m² depending on conditions, conservatories ≤30m², porches, carports). Some work is exempt from the application process but still must comply with the Regulations (notifiable electrical work under Part P registered competent person scheme). Always check before assuming exemption — penalties for unauthorised work include enforcement notice and uninsured liability.

Summary

The Building Regulations 2010 apply to building work in England and Wales (Wales operates a separate but similar regime). They cover the construction and material alteration of buildings, services, fittings and certain other works. Most work needs either a Full Plans Application (detailed drawings submitted in advance) or a Building Notice (commencement notice with site inspection) — both lead to a Completion Certificate at the end.

But not all work needs approval. Schedule 2 of the Regulations lists categories that are exempt from the application process. Common exemptions include small detached buildings (within size and proximity limits), conservatories with specified configurations, porches, carports, and certain agricultural buildings. The exemption is from the application process — exempt buildings still need to comply with the underlying performance requirements (a conservatory that collapses or is unsafe is still a problem; it's just that no Building Control inspector vetted it in advance).

Separately, some work is notifiable through a competent person scheme rather than via Building Control. The most common is notifiable electrical work under Part P — replacements and additions in special locations (bathrooms, near pools, outside) must be done by a registered electrician (NICEIC, NAPIT, ELECSA, STROMA) who self-certifies via the competent person scheme. This satisfies notification without a Building Control application.

For tradespeople, the rules separate three states: (1) exempt — no approval needed; (2) notifiable — needs Building Control or competent person scheme; (3) requires approval — full Building Regulations process. See building regs exemptions for Schedule 2 details and building regs overview for the regulations overview.

Key Facts

• Building Regulations 2010 — primary regulations in England; SI 2010/2214
• Schedule 2 — lists exempt categories
• Schedule 3 — lists self-certification schemes (Part P, gas, oil, others)
• Approved Documents — guidance on how to meet the regulations (Parts A through R + Appendix)
• Full Plans Application — submitted in advance; checked before work; preferred for complex work
• Building Notice — submitted just before starting; minimal upfront detail; inspector visits during build
• Completion Certificate — issued after final inspection; required for sale/mortgage
• Class 1 (Sch 2) — buildings controlled under other legislation (e.g. lighthouses)
• Class 2 (Sch 2) — buildings not frequented by people (telephone kiosks, plant rooms)
• Class 3 (Sch 2) — greenhouses and agricultural buildings within conditions
• Class 4 (Sch 2) — temporary buildings (≤28 days)
• Class 5 (Sch 2) — ancillary buildings (e.g. site huts)
• Class 6 (Sch 2) — small detached buildings (≤15m² no sleeping, OR ≤30m² with 1m boundary distance)
• Class 7 (Sch 2) — extensions: conservatories ≤30m², porches ≤30m², carports open on ≥2 sides
• Part P Notifiable Work — fuse box changes, new circuits, work in bathroom zones, outside
• Competent person schemes — Electrical (NICEIC, NAPIT, ELECSA, STROMA), Gas (Gas Safe), Oil (OFTEC), Solid fuel (HETAS), Heat pumps (MCS)
• Enforcement notice — requires unauthorised work to be removed or made compliant; 28-day appeal
• Regularisation — retrospective application for unauthorised work; higher fee; cannot guarantee compliance
• Penalty — £5,000 per offence + £50/day; Magistrates' Court

Quick Reference Table

Detailed Guidance

The three regulatory states

State 1: Exempt — work falls in Schedule 2 category and conditions are met. No application, no notification, no inspection. The work must still comply with the Regulations' performance requirements (structure safe, fire safe, etc.) but no proof of compliance is needed unless challenged.

State 2: Notifiable via competent person — work is notifiable but a registered scheme member (electrician, gas engineer, oil installer) can self-certify via their scheme. The scheme notifies Building Control on the homeowner's behalf and issues a compliance certificate. No Building Control inspection in person; the scheme oversees the registered person.

State 3: Building Regulations Application — Full Plans or Building Notice to Building Control. Site inspections at first fix and completion. Completion Certificate issued. Required for most material construction work.

Schedule 2 exemptions — class by class

Class 1 — Buildings controlled under other legislation Specifically: buildings controlled by the Explosives Acts, Civil Aviation Authority, Atomic Energy Authority, lighthouses. Rare for domestic tradespeople.

Class 2 — Buildings not frequented by people Detached buildings used for purposes not requiring people to be inside regularly. Conditions: more than 1.5× the building's height away from the nearest building used by people; or distance equal to height if shorter.

Typical: small electric substation kiosks, agricultural machinery stores.

Class 3 — Greenhouses and agricultural buildings Detached greenhouses; detached agricultural buildings used solely for agriculture (not sleeping accommodation or processing/sale of produce). Conditions specify boundary distance and use restrictions.

Class 4 — Temporary buildings Buildings intended to remain for not more than 28 days. Site huts, marquees with structural elements, etc.

Class 5 — Ancillary buildings Buildings on construction sites used for temporary accommodation, plant or material storage; small ancillary buildings to caravan sites.

Class 6 — Small detached buildings Two subclasses:

• ≤15m² floor area, no sleeping accommodation — exempt regardless of boundary distance
• ≤30m² floor area, ≥1m from any boundary, no sleeping accommodation, AND (if within 1m of boundary) non-combustible construction

Common application: detached garages, garden offices (without sleeping), workshops, sheds.

Watch points:

• "No sleeping accommodation" is strict — any provision for overnight sleeping voids the exemption
• The 1m boundary measurement is to the nearest part of the building, not the foundation
• "Non-combustible" means substantially non-combustible structure — typically masonry walls, metal frame, slate roof

Class 7 — Conservatories, porches and carports Conservatories must:

• Be ≤30m² floor area
• Be at ground level
• Be separated from the main dwelling by a door, window or wall (not just a curtain or opening)
• Have a roof of which at least 50% is translucent
• Have walls of which at least 50% are translucent

Conservatories not meeting these conditions are not exempt — they need Building Regulations approval and must achieve standard insulation U-values.

Porches must:

• Be ≤30m² floor area
• Be at ground level
• Have walls and roof of which at least 75% are translucent (varies by interpretation)

Carports must:

• Be ≤30m² floor area
• Be open on at least two sides

Part P notifiable electrical work

Part P applies to all fixed electrical installations in dwellings. The regulations specify:

• All work must comply with BS 7671 (the IET Wiring Regulations)
• Notifiable work (specific categories) must be either:
  • Done by a registered competent person who self-certifies; OR
  • Notified to Building Control in advance and inspected

Notifiable categories:

• Installation of a new circuit
• Replacement of a consumer unit
• Any addition or alteration in a special location (bathroom, swimming pool, sauna, outside)

Non-notifiable work (still must comply with BS 7671):

• Replacing a like-for-like socket/switch
• Adding a fused spur to an existing circuit (outside special locations)
• Replacing a light fitting
• Repairing damaged cables

For non-registered electricians, notifiable work must go through Building Control: application before starting + inspection + Building Control compliance certificate. This is slower and more expensive than registered competent person route — most electricians work via a scheme.

Gas work notification

All gas work in domestic property must be carried out by a Gas Safe registered engineer (unless the homeowner does basic work to their own appliance, which is permitted but generally inadvisable). Gas Safe Register handles the notification — the engineer notifies the scheme of installation, alteration or service.

Heating system replacements

Like-for-like boiler replacements: Gas Safe (or HETAS for solid fuel, OFTEC for oil) registered engineer notifies via their scheme. No Building Control application.

New boiler in different location, or new flue penetration, or major system changes: additional Building Control involvement may be needed (Part L compliance, F gas refrigerant handling, condensate disposal).

Replacement windows and doors

Glazed window or door replacements must achieve Part L U-value targets (typically 1.4 W/m²K for windows from 2021):

• FENSA registered installer: certifies compliance, notifies Building Control
• CERTASS registered installer: same as FENSA
• Non-registered: Building Notice to Building Control + inspection

A handful of cases are exempt (porch internal door, garage door not in dwelling envelope). Most replacement windows are notifiable.

When to apply for Building Regs

For non-exempt, non-self-certifiable work:

Full Plans Application:

• Submit detailed drawings, structural calcs, specifications
• Building Control checks before work starts
• Issues a Plans Decision (approval, approval with conditions, rejection)
• Inspection at first fix, completion
• Completion Certificate at end

Use Full Plans for: extensions, loft conversions, structural alterations, complex work where you want certainty before starting.

Building Notice:

• Submit short notice and basic drawings
• Building Control does NOT check before work starts
• Inspections during construction
• Completion Certificate at end

Use Building Notice for: simple work where you're confident of compliance, where you'd prefer to start immediately.

Consequences of unauthorised work

Work done without required approval is unauthorised. Consequences:

• Enforcement notice — requires removal or making compliant within 28 days
• Section 36 Notice (Building Act 1984) — Local Authority can require work to be cut into to verify compliance
• Prosecution — Magistrates' Court; £5,000 per offence + £50/day continuing
• Civil liability — uninsured if defective; potential injury liability
• Sale impact — solicitor will identify lack of certification; buyer may withdraw, demand price reduction, or refuse to proceed
• Regularisation — retrospective application possible (higher fee, ~150% of normal) but cannot guarantee approval; may not be possible if work doesn't actually comply

Frequently Asked Questions

Is a garden office an exempt building?

It depends on size, position and use. A detached garden office:

• ≤15m² with no sleeping accommodation — exempt
• 15-30m², ≥1m from boundary, no sleeping — exempt (non-combustible if within 1m)
• Larger than 30m² — not exempt
• Sleeping accommodation, however small — not exempt; full Building Regs apply

A "garden room" with a bed and toilet is effectively an annex/extension and needs Building Regs (and may need planning).

Does my customer need approval to replace their boiler?

If the replacement is in the same location with no flue route change: Gas Safe (or OFTEC for oil) engineer notifies via their scheme. No Building Control application needed.

If the location changes, flue route changes, or there are other significant alterations: additional Building Control involvement may be needed for Part L (energy efficiency), Part B (fire), Part J (combustion appliance) compliance.

Can I add sockets to an existing circuit without notification?

Outside special locations (i.e. not in a bathroom, not outside), yes — adding sockets or a fused spur to an existing circuit is non-notifiable and can be done by a competent householder or unregistered electrician. It must still comply with BS 7671 (the Wiring Regulations) but no Part P notification is required.

Inside a bathroom, near a swimming pool, or outside the dwelling — any addition is notifiable.

Why do I need a FENSA certificate for replacement windows?

Part L requires replacement windows to meet U-value 1.4 W/m²K. FENSA and CERTASS are competent person schemes for window installers — registered installers self-certify and the scheme notifies Building Control. The certificate proves compliance and is needed for property sale. Without a certificate, retrospective approval is needed (more expensive, may not be granted).

Are works to a listed building exempt from Building Regulations?

No. Listed Building Consent (from the local authority) is required IN ADDITION to Building Regulations — not instead of. The Listed Building consent covers heritage impact; Building Regulations cover structural/safety/energy compliance. Both processes are run in parallel.

What if I'm not sure whether work needs approval?

Contact the Building Control team at the local authority. They will advise on the specific circumstances. Most authorities offer this advice free or low cost — it's faster and cheaper than doing the work and then arguing about compliance. Some offer pre-application advice for a fixed fee.

Can I rely on the previous owner's Building Regs certificate?

For work done by the previous owner, yes — the Completion Certificate covers that work. For your new work, you need a fresh certificate (or competent person notification). The original certificate doesn't extend to subsequent alterations.

What's the difference between planning permission and Building Regulations?

Planning permission concerns whether the building can exist on the site (size, appearance, impact on neighbours, conservation). Building Regulations concern whether the building is safe and complies with technical standards (structure, fire, energy, accessibility). The two are independent — a building can be permitted development (no planning needed) but still need Building Regs approval. Likewise, planning permission doesn't certify Building Regulations compliance.

Regulations & Standards

• The Building Act 1984 — primary legislation

• The Building Regulations 2010 (SI 2010/2214) — current regulations

• Schedule 2 — exempt buildings categories

• Schedule 3 — notifiable competent person schemes

• Approved Documents A–R — practical guidance for compliance

• BS 7671:2018+A2:2022 — IET Wiring Regulations

• Gas Safety (Installation and Use) Regulations 1998 — gas work

• The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 — alarms

• The Town and Country Planning Act 1990 — planning (separate from Building Regs)

• The Listed Buildings and Conservation Areas Act 1990 — listed building consent

• The Construction (Design and Management) Regulations 2015 — CDM

• Building Safety Act 2022 — applies to higher-risk buildings; tightens regulatory regime

• Approved Documents (gov.uk)

• Schedule 2 — Building Regulations 2010

• Schedule 3 — Self-certification schemes

• Planning Portal — Building Regulations

• LABC — Local Authority Building Control

• building regs exemptions — Schedule 2 details

• building regs overview — Building Regulations Approved Documents overview

• planning vs building regs — planning vs Building Regs

• building regs part k — Part K Protection from falling

• electrical installation condition report — EICR for Part P

• hmo licensing — HMO licensing requirements