Building Regulations Part P: Electrical Safety in London Homes — What Requires Notification and Who Can Do the Work

**The fundamental rule under Part P**:

• Building Regulations Part P requires that electrical installation work in dwellinghouses is designed, installed, inspected, and tested in accordance with BS 7671 (the IET Wiring Regulations, 18th edition). It also requires that certain categories of 'notifiable' electrical work are either:
• •Carried out by a registered competent person (an electrician registered with a government-approved competent person scheme — NICEIC, ELECSA, NAPIT, etc.), who self-certifies the work, OR
• •Notified to the Local Authority Building Control before the work starts (or in an emergency, as soon as possible afterwards), and inspected and tested by a qualified inspector

**Notifiable electrical work under Part P (2025)**:

The following categories of electrical work in a dwellinghouse are notifiable:

• *1. Installation of a new circuit*:
• Any new circuit from the consumer unit (fuse board / distribution board) is notifiable — including:
• •A new power circuit (ring final or radial) for a new extension or room
• •A new lighting circuit
• •A new dedicated circuit for an EV charger
• •A new circuit for an electric shower or electric cooker
• •A new circuit for underfloor heating
• •A new circuit for garden power points

*2. Replacement of a consumer unit (fuse board)*: Replacing the consumer unit is notifiable. Consumer unit replacements are common on renovation projects where the existing board is old (pre-RCD protection) or insufficient for the additional circuits added by the extension.

• *3. Additional work (new cable, sockets, switches) in special locations*:
• Special locations include:
• •Kitchens (within 3m of the sink, basin, or cooking appliance zones in a kitchen)
• •Bathrooms, shower rooms, and wet rooms
• •Swimming pools, hot tubs, and outdoor water features
• •Around swimming pools and hot tubs

In these special locations, virtually any new wiring work is notifiable — adding a new socket, installing a light fitting, adding a fan — because these areas carry a higher risk of electric shock from moisture.

**What is NOT notifiable under Part P**:

• •Adding a new socket or light fitting to an existing circuit (other than in a special location)
• •Replacing an existing fitting like-for-like (replacing a socket, a light switch, or a light fitting with an identical type — not adding a new circuit)
• •Replacing cable damaged during fault repair (repair work)
• •Outdoor lighting connected to an existing circuit
• •Installing a self-contained low-voltage garden lighting system (plug-in or 12V)
• •Replacing a storage heater like-for-like (same circuit, same location)

**Why the distinction matters for a London extension or refurbishment**:

• For a standard single-storey rear extension, virtually all electrical work will be notifiable — because:
• •A new power circuit (ring or radial) will be installed for the extension sockets
• •A new lighting circuit will be installed for the extension lights
• •If underfloor heating is installed, a new circuit is required
• •If any sockets or fittings are installed in the kitchen (even in the extension area), that is notifiable work in a special location

For a full refurbishment, the electrical works are almost always entirely notifiable — new circuits throughout, typically a new consumer unit, new wiring in bathroom and kitchen (special locations).

**The implication for planning your London extension or refurbishment**:

• Because almost all extension and refurbishment electrical works are notifiable, the electrician carrying them out MUST be either:
• •A registered competent person (NICEIC, ELECSA, NAPIT, or another government-approved scheme member) who can self-certify the work and issue the Building Regulations compliance certificate directly, OR
• •A non-registered electrician who notifies Building Control, has the work inspected during and after installation, and obtains a completion certificate from Building Control

In London, most professional electricians working on residential extension and refurbishment projects are registered with a competent person scheme — NICEIC and ELECSA are the two most widely used. RCB's preferred electrical subcontractors are all registered with an approved scheme and issue the required documentation upon completion.

**Competent person schemes — how they work**:

A competent person scheme (CPS) is a government-approved scheme that allows trades to self-certify their work against Building Regulations without involving Building Control. For electrical works under Part P, the government-approved CPS operators include:

• •**NICEIC** (National Inspection Council for Electrical Installation Contracting) — the largest and most widely recognised scheme for residential electrical contractors
• •**ELECSA** — the scheme run by NICEIC for smaller/sole trader electricians
• •**NAPIT** — National Association of Professional Inspectors and Testers
• •**STROMA Certification**

• Electricians registered with these schemes:
• •Assess the installation against BS 7671 during and after installation
• •Issue an Electrical Installation Certificate (EIC) for new installations or a Minor Electrical Installation Works Certificate (MEIWC) for smaller additions
• •Notify the LPA Building Control of the completed work (the scheme does this on the electrician's behalf)
• •The LPA Building Control issues a Building Regulations Compliance Certificate to the homeowner confirming the work has been certified

**What is an Electrical Installation Certificate (EIC)?**

• The Electrical Installation Certificate (EIC) is the certificate issued by the electrician at the end of notifiable electrical works. It confirms that:
• •The installation has been designed in accordance with BS 7671
• •The installation has been installed in accordance with the design
• •The installation has been tested and inspected in accordance with BS 7671 Part 6
• •The test results are within the prescribed limits

For a London extension where new circuits have been installed, the electrician issues an EIC covering the new circuits. If the project involves replacement of the consumer unit, the EIC covers the whole installation (from the consumer unit onwards).

The EIC is one of the documents included in the health and safety file at practical completion and must be provided to the homeowner. Without it, the homeowner does not have documentation that the electrical installation was tested and certified — which is a problem at conveyancing.

**Electrical Installation Condition Report (EICR) — a different document**:

• The EICR (Electrical Installation Condition Report) is NOT the same as the EIC. The EICR is an inspection report on an EXISTING installation — checking its condition and identifying any departures from BS 7671. An EICR:
• •Is required every 5 years for HMO (Houses in Multiple Occupation) rental properties under the Electrical Safety Standards in the Private Rented Sector Regulations 2020
• •Is recommended every 10 years for owner-occupied properties (EICR on purchase is standard practice)
• •Identifies codes C1 (danger present), C2 (potential danger), C3 (improvement recommended), and FI (further investigation required)
• •Is produced by an electrician registered with a competent person scheme or a qualified inspector

For a London homeowner buying a property and planning a refurbishment: the pre-purchase building survey may recommend an EICR to assess the existing electrical installation before the refurbishment works are planned. This is good practice — particularly for properties with pre-1990 wiring or rubber-insulated cable (identifiable by its round cross-section and brown/black rubber insulation rather than modern PVC).

**Part P compliance at conveyancing — what buyer's solicitors ask for**:

• When a London property with recent electrical works is sold, the buyer's solicitor will ask as part of the property enquiries:
• •Whether any notifiable electrical works have been carried out since the property was built
• •Whether an Electrical Installation Certificate or Building Control Completion Certificate exists for those works

• If the seller cannot produce this documentation, the buyer's solicitor will typically require either:
• •Retrospective inspection and certification by a registered electrician (who inspects the existing works and certifies them if they comply with BS 7671) — cost: £200–£500 per installation
• •Indemnity insurance — which protects the buyer against the consequences of non-compliance but does not establish that the installation is actually safe

The best approach is always to obtain the EIC from the electrician at the time the works are completed — not to try to retrospectively certify works years later when the installation may have been modified or the original electrician may no longer be available.

**Part P and HMO properties**:

• For London HMO (Houses in Multiple Occupation) properties, the electrical requirements are more stringent:
• •An EICR must be obtained before the HMO is first let and renewed every 5 years (or after any rewiring)
• •All electrical installations must comply with the national minimum standards for electrical safety
• •Fire alarm systems must be BS 5839 compliant (typically at least Grade D, LD2 for small HMOs; Grade A/L1/L2 for larger HMOs)
• •Emergency lighting must comply with BS 5266 where required by fire risk assessment
• •All sockets, switches, and fittings must be in good working order

For a London HMO conversion project, the electrical specification must be planned from the start to meet both Part P (new circuit notification) and the HMO licensing electrical standards — these are separate but related requirements.

**EV charger installation and Part P**:

• Electric vehicle (EV) charger installations in dwellinghouses are notifiable under Part P because they require a new dedicated circuit from the consumer unit. In addition to Part P compliance, EV charger installations in England also require:
• •Building Regulations Part P notification (new circuit installation)
• •Compliance with the Electric Vehicles (Smart Charge Points) Regulations 2021 — which require that any EV charge point installed in a domestic premises after June 2022 is a 'smart' charge point capable of responding to time-of-use signals
• •OZEV registration by the installer (the installer of the EV charger must be registered with the Office for Zero Emission Vehicles to carry out domestic installations)

Cost of domestic EV charger installation in London (2025): £700–£1,200 for a 7kW single-phase smart home charger, including OZEV-registered installer fee and Part P notification. The Workplace Charging Scheme (WCS) and Electric Vehicle Infrastructure Grant (for domestic properties) may provide grant funding — check current eligibility.

For a London extension project where an EV charger is to be installed, the EV charger installation should be planned alongside the electrical works for the extension — ideally using the same electrician who is installing the extension circuits, to minimise consumer unit work and ensure coordinated testing and certification.

**Solar photovoltaic (solar PV) installation and Part P**:

Solar PV installations on a dwellinghouse involve both the AC connection to the consumer unit (which is notifiable under Part P and must be carried out by or certified by a competent person scheme member) and potentially planning permission (for roof panels on a listed building or in some conservation areas — otherwise typically permitted development for most residential properties in England under Class A of the GPDO).

• For a London extension incorporating a solar PV array on the new flat roof:
• •The PV panels and inverter installation: typically carried out by an MCS-registered (Microgeneration Certification Scheme) installer — this is required for Smart Export Guarantee (SEG) tariff eligibility
• •The AC connection to the consumer unit: notifiable Part P work — included in the electrician's EIC for the project
• •Consumer unit upgrade: typically required for PV installations of any significant size, to accommodate the additional circuit and the generation meter

**Underfloor heating (UFH) and Part P**:

• Underfloor heating in a London extension is typically electric (electric resistance mat or cable, particularly for wet room or tiled floor areas) or hydronic (water-based UFH from the central heating system, which is plumbing-based and not Part P). Electric UFH:
• •Requires a new dedicated circuit from the consumer unit (notifiable Part P work)
• •The circuit must include an appropriate overcurrent and RCD protection device
• •The thermostat/controller must be installed within the zone it controls (or remotely, in compliance with the UFH manufacturer's specification)

For a London extension with a tiled floor and underfloor heating, the electrical contractor must certify the UFH circuit as part of the overall EIC for the extension electrical works.

**What to do if Part P certification is missing for previous works**:

A common situation in London — particularly for older properties where electrical works were carried out before Part P was introduced (January 2005), or where previous owners had works done without proper certification — is that there is no EIC or Building Control certificate for existing electrical works.

Options for the current homeowner:

*Option 1 — Commission a retrospective inspection and EICR*: Have an NICEIC or ELECSA registered electrician inspect the existing installation and issue an EICR. If the installation is found to be in satisfactory condition (no C1 or C2 codes), the EICR acts as evidence of current compliance. Cost: £200–£400 for a standard domestic property.

*Option 2 — Notified rewire during a refurbishment project*: If the property is being refurbished, include a full or partial rewire in the scope of works and ensure the new works are carried out by a registered electrician who issues an EIC. This kills two birds with one stone: the installation is updated to current standards AND the documentation issue is resolved.

*Option 3 — Indemnity insurance at sale*: If the property is being sold and there is no documentation for previous electrical works, the seller's solicitor may offer indemnity insurance to the buyer. This is a last resort — it protects the buyer legally but does not establish that the installation is safe. Good buyers' solicitors in London will advise their clients to request an EICR before exchange rather than accept indemnity insurance for electrical works.