Building Regulations
& Legal Requirements
Building Regulations and the legal framework behind every compliant extension — explained in plain English so you know exactly what's required before, during and after your build.
Work on Your Own Home: The Legal Bit
Building work in England is governed by Building Regulations — and a key split: whether the work is notifiable (needs council sign-off) or non-notifiable. Here's what applies, and what you must do before, during and after.
Notifiable Work
- New builds, extensions and loft or garage conversions
- Structural alterations — removing load-bearing walls, underpinning
- New or altered drainage, bathrooms and WCs
- Electrical work in bathrooms, kitchens or outdoors, and new circuits
- Replacement windows and external doors (unless fitted by a competent person)
- Roof re-covering, cavity wall insulation and change of use
Non-Notifiable Work
- Like-for-like repairs and replacements (plaster, floorboards, radiators)
- Redecorating, painting and minor cosmetic work
- Replacing sockets or light fittings on an existing circuit (not in a special location)
- Minor drain repairs and routine maintenance
- Garden walls, sheds and small outbuildings within permitted limits
- Replacing a single floor covering on a like-for-like basis
Likely Duration & Trades
| Project | Indicative Duration | Trades on Site |
|---|---|---|
| Single-storey extension (20–30 m²) | 8–12 weeks | 6–8 trades |
| Two-storey extension | 16–24 weeks | 8–10 trades |
| Loft conversion | 6–10 weeks | 4–6 trades |
| Garage conversion | 4–8 weeks | 4–6 trades |
| Whole-house renovation | 12–24 weeks | 10+ trades |
Indicative only — larger or more complex projects take longer. We'll give a project-specific programme before we start.
Before works start
- Confirm whether Planning Permission is required (separate from Building Regs)
- Submit a Building Control application — Full Plans or a Building Notice
- Serve Party Wall etc. Act 1996 notices to adjoining owners if relevant
- Obtain structural calculations and construction drawings
- Arrange skip, materials-on-highway and scaffolding permits if on the road
- Commission an asbestos survey for any property built before 2000
- Check your home insurance covers the works; arrange a structural warranty
During the build
- Book Building Control inspections at set stages (foundations, damp-proof, drains, structure)
- Keep the site safe and segregated — protect neighbours, pedestrians and the highway
- Collect competence certificates (Gas Safe, NICEIC/NAPIT, FENSA) from each trade
- Retain test records for electrical, drainage and any structural elements
- Notify Building Control of any change to the approved design before it's built
After completion
- Obtain the Building Control Completion Certificate — keep it with your property records
- Secure electrical (Part P), gas and boiler commissioning certificates
- Finalise Party Wall agreements and any warranty registrations
- Retain a full set of as-built drawings, calcs and trade certificates for resale
- Notify your insurer once the works are complete and the property is reinstated
Planning ≠ Building RegsPlanning Permission and Building Regulations are separate regimes. Some work needs both, some only one, some neither. We identify exactly what your project requires up front so there are no surprises.
The Acts That Govern the Build
Construction work is one of the most heavily regulated industries in the UK. Even on your own home, a stack of statutes applies — and different duties switch on at different points in the project.
Health & Safety at Work etc Act 1974
The umbrella Act. Everyone on site — employer, self-employed and (for domestic projects) the contractor — owes a duty to protect workers, visitors and the public from harm.
Construction (Design & Management) Regs 2015
Applies to ALL construction work including on homes. Sets duty-holders (Client, Designer, Principal Designer, Principal Contractor) and requires a construction phase plan before work starts. For domestic clients, duties normally pass to the contractor or designer.
Work at Height Regulations 2005
Covers any work where a person could be injured by falling — roofing, scaffolding, working off stepladders or first-fix at height. Requires planning, competent people and suitable edge protection.
Control of Asbestos Regulations 2012
A duty to identify and manage asbestos before work in any property built before 2000. Disturbing asbestos without assessment is a criminal offence.
Control of Substances Hazardous to Health Regs 2002
Risk assessment and control of cement, solvents, adhesives, silica dust and treated timber. Applies whenever hazardous substances are used or created.
Electricity at Work Regulations 1989
Temporary site supplies, isolation and safe electrical systems must be maintained throughout the works.
Provision & Use of Work Equipment Regs 1998
All tools and machinery must be suitable, maintained and used only by trained, competent operatives.
Manual Handling Operations Regulations 1992
Assess and avoid risky lifting of heavy materials where reasonably practicable.
Control of Noise at Work Regulations 2005
Protects workers from harmful noise. Separate from the duty to avoid noise nuisance to neighbours under the Environmental Protection Act 1990.
Regulatory Reform (Fire Safety) Order 2005
Fire risk during hot works and for the finished building. A fire risk assessment is required for the completed premises.
When Each Duty Kicks In
Pre-construction & Design
- HSWA duty of care begins for all duty-holders
- CDM 2015 — Client appoints Principal Designer & Principal Contractor; a construction phase plan is prepared
- Control of Asbestos Regs — survey and risk assessment for pre-2000 properties
- COSHH — assessments for any hazardous substances to be used
Mobilisation & Set-up
- Work at Height Regs — assessment before erecting scaffolding or roof access
- PUWER — site tools and machinery checked and certified
- Electricity at Work Regs — temporary supply installed and isolated safely
- Manual Handling Regs — lift plans for heavy materials
Construction On Site
- Work at Height Regs active during roofing, scaffolding and high-level first fix
- COSHH applies whenever solvents, cement, adhesives or silica dust are present
- Noise Regs and Environmental Protection Act during demolition and power-tool use
- Fire Safety Order — permits and controls for any hot works (welding, soldering)
Handover & Completion
- Fire Safety Order — a fire risk assessment for the finished premises
- Electrical (Part P) and gas safety certificates retained
- Building Regulations 2010 — completion certificate issued
- All CDM records, risk assessments and trade certificates handed to the client
We carry the legal burdenAs your Principal Contractor we discharge these duties on your behalf — keeping you, your neighbours and the public protected and your project compliant end to end.
Building Regulations in England
An extension isn't finished when it's built — it's finished when building control signs it off. Here's what the rules now require, and the new regime that's reshaped building control and inspections.
Approval Is Required
Almost every extension needs Building Regulations approval — not to be confused with planning permission. Small exempt structures (e.g. a porch under 5m² or certain conservatories under 30m² with separating doors) are the narrow exceptions.
Two Routes to Comply
You can submit Full Plans for checking before work starts, or a Building Notice for smaller jobs. We'll advise which route suits your project and prepare the submission either way.
Completion Certificate
Once building control is satisfied, a Completion Certificate is issued. It's essential — lenders and conveyancers ask for it when you sell. We manage the process end-to-end so the paperwork is never missing.
New Rules for Building Control
New Building Control Regime
Under the Building Safety Act 2022, the old 'Approved Inspectors' are now Registered Building Control Approvers (RBCAs), overseen by the Building Safety Regulator. Higher standards, stronger accountability, and a clearer enforcement route — in force and being expanded through 2025.
Mandatory Inspections
Building control must inspect at set stages — foundations, oversite/damp-proof, structural elements, drainage and completion. Work can't proceed past a stage until it's signed off. We schedule and host every inspection.
Stricter Enforcement
The 2025 amendments tighten competence requirements for building control bodies and introduce new offence provisions for non-compliant work. Cutting corners now carries real legal and financial risk — proper compliance has never mattered more.
Key Approved Documents for Extensions
Conservation of Fuel & Power
Uplifted standards for fabric insulation, glazing and heating. Extensions must meet strict U-value targets and limit heat loss — directly supporting low-carbon goals.
Ventilation
Adequate ventilation must be designed in — trickle vents, extract fans and background ventilation — so a more airtight extension stays healthy and damp-free.
Overheating
New residential buildings (including extensions creating new habitable space) must limit solar gains and provide usable mitigation against overheating in summer.
Fire Safety
Means of escape, fire resistance, smoke alarms and — for multi-storey work — protected escape routes and interlinked detection.
EV Charging
Where new or renovated parking is provided, electric-vehicle charging infrastructure must be included.
Structure
Foundations, beams, walls and roofs must be structurally sound — calculated and signed off, particularly for openings and removed load-bearing elements.
The Inspection Journey
Commencement
Notice given to building control before works start.
Foundations
Inspection of excavation and concrete pour depth.
Oversite / DPC
Damp-proof course and sub-floor insulation checked.
Structure
Steelwork, beams, timber frame and structural elements.
Drainage
Below-ground drains tested before backfilling.
Completion
Final inspection and issue of Completion Certificate.
We Handle the LotFrom submission to final certificate, we manage building control on your behalf — coordinating inspectors, demonstrating compliance and keeping your project on the right side of the new regime.
Discuss Your ExtensionElectrical Work: BS 7671 & Part P
All electrical work in English homes must meet BS 7671 (the IET Wiring Regulations) and Part P of the Building Regulations. Some work must be notified to Building Control or self-certified by a registered competent person — here's what applies and when.
IET Wiring Regulations
The national standard for fixed electrical installation in the UK. The 18th Edition (plus amendments) defines how all domestic, commercial and industrial installations must be designed, installed and inspected. Not a statute, but cited by Building Regulations as the benchmark for compliance.
- Design, installation, inspection & testing requirements
- Updated periodically — currently Amendment 2 in force
- Applied alongside Part P for all domestic work
Building Regulations
Part P of the Building Regulations governs electrical safety in dwellings. All electrical work in homes — and in the special locations around them — must be safe, comply with BS 7671, and be either notified to Building Control or self-certified by a registered competent person.
- Applies to all electrical work in dwellings
- Requires compliance with BS 7671
- Completion recorded via Building Control or a competent person scheme
Notifiable Electrical Work
- New circuits and circuit alterations
- Consumer unit (fuse box) replacement
- Work in a bathroom, shower room or sauna
- Outdoor electrical installations and garden lighting
- Work near swimming pools or hot tubs
- Installation of electric showers or high-power appliances
Non-Notifiable Work
- Like-for-like replacement of accessories (sockets, switches, light fittings)
- Minor work on existing circuits outside special locations
- Replacing a damaged cable for a single circuit
- Installing extra sockets or lights on an existing ring or radial circuit (non-special location)
- Maintenance of existing equipment and re-fixing accessories
Competent Person Schemes
Notifiable work can be self-certified by an electrician registered with an approved scheme — they issue the certificate and notify Building Control on your behalf. No separate council application is needed.
National Inspection Council for Electrical Installation Contracting
National Association of Professional Inspectors and Testers
Electrical Contractors' Certification Scheme (now part of NAPIT)
Competent person scheme for building services
Special Locations
Bathrooms & shower rooms
Zones 0–2 require IP-rated fittings; RCD protection mandatory; metal parts bonded to earth.
Kitchens
RCD protection on all socket outlets; dedicated circuits for high-load appliances.
Outdoors & gardens
All outdoor circuits RCD-protected; weatherproof IP-rated enclosures; armoured cable for buried runs.
Swimming pools & hot tubs
Strict zoning; IPX-rated equipment; equipotential bonding; isolation switch within sight.
Bathroom Zones & Devices
BS 7671 splits a bathroom into zones based on water exposure. The zone dictates the minimum IP rating and which devices may be installed. No 13A socket outlet is permitted within 3 metres of the edge of a bath or shower.
IPX7 (immersion-proof). Only fixed equipment designed for submersion, e.g. underwater lights. SELV only (≤ 12V AC).
IPX4 minimum, up to 2.25m high / 1.2m radius. Only SELV shaver units, shower switches and IPX4-rated fixed equipment.
IPX4 minimum. Shaver sockets (BS EN 61558-2-5) and IPX4 lighting permitted. No general sockets.
General 13A sockets and wall switches permitted, RCD protected. Pull-cord switches always preferred.
| Device | Zone 0 | Zone 1 | Zone 2 | Outside | Notes |
|---|---|---|---|---|---|
| 13A socket outlet | Min. 3m from bath/shower edge, RCD protected | ||||
| Shaver socket (SELV, BS EN 61558-2-5) | Isolating transformer, no direct mains | ||||
| Light fitting | IPX7 | IPX4 | IPX4 | RCD | Rating depends on zone |
| Wall-mounted switch | Outside all zones only | ||||
| Pull-cord switch | Preferred for ceiling control | ||||
| Heated towel rail | IPX4 | IPX4 | Fixed, RCD protected | ||
| Electric shower unit | IPX4 | IPX4 | Manufacturer-rated for zone | ||
| Extractor fan | IPX4 | IPX4 | RCD protected, IPX4 if in zone |
IPX4 = splash-proof · IPX7 = immersion-proof (1m, 30 min) · SELV = separated extra-low voltage (≤ 12V AC). All circuits in a bathroom must be RCD-protected (30mA, 30ms).
EICR — Electrical Installation Condition ReportRental properties in England require an EICR every 5 years under the Electrical Safety Standards Regulations 2020. We arrange periodic inspection and testing so your installation stays certified and safe.
Party Walls & Boundaries
If your extension or excavation touches a shared wall or boundary, the Party Wall etc Act 1996 gives you a legal duty to notify your neighbours and, if they dissent, agree a binding Award before you start.
When the Act Applies
It covers shared walls, boundary structures and nearby excavation — not routine maintenance like plastering or fixing shelves.
Notifiable work
- Building astride or up to the boundary
- Cutting into a party wall (e.g. beam pockets)
- Raising, lowering or underpinning a party wall
- Demolishing / rebuilding a party wall
Excavation trigger
- Within 3 m & deeper than neighbour's foundations
- Within 6 m where it would undermine them
- Excludes ordinary household excavation
The Five-Step Process
Check the Act applies
Work is notifiable if it involves: building on or up to the boundary line; cutting into a shared wall (e.g. inserting a steel beam); raising, lowering, underpinning or demolishing a party wall; or excavating within 3–6 m of a neighbouring structure and below their foundation level.
Serve the notices
Give written notice to every affected adjoining owner at least two months before starting work on a party wall, or one month before excavation/party fence work. Notice must state the work, the date, the address and a clear description.
Wait for the response
Adjoining owners have 14 days to consent or dissent. If they consent in writing, work may proceed. If they dissent or do nothing, or your work affects both sides, a Party Wall Award (agreement) is required.
Agree a Party Wall Award
If a dispute arises, you and the neighbour jointly appoint an agreed surveyor — or each appoint your own — to draw up a binding Award covering how the work is done, a Schedule of Condition of the neighbour's property, and who pays the surveyor's fees (normally the building owner).
Carry out work to the Award
Work must follow the Award exactly. The Schedule of Condition is used to settle any later damage claim. The Act is a civil framework — breach can lead to injunctions and damages, but no criminal penalty. Notify neighbours again 14 days before you actually start.
The Statutory Forms
Party Structure Notice
Work to an existing party wall — raising, underpinning, cutting in beams or demolishing/rebuilding. Minimum 2 months' notice.
Line of Junction Notice
Building a new wall astride the boundary or wholly on your own land up to the line of junction. Minimum 1 month's notice.
Party Fence Wall Notice
Building or altering a wall that is a party fence wall (a wall that is not part of a building) on the boundary. Minimum 1 month's notice.
Notice of Adjacent Excavation
Excavating within 3 m (and deeper than the neighbour's foundations) or within 6 m (where the excavation would undermine their foundations). Minimum 1 month's notice.
Notice periods
2 months for party structure work; 1 month for line-of-junction, party fence and adjacent excavation notices.
The Award
A binding document prepared by surveyors. It includes a Schedule of Condition to settle any later damage claim and confirms who pays the fees.
If you skip it
The Act is civil — but neighbours can win an injunction stopping your build, plus damages. Self-builds and works to flats are all in scope.
Need party wall notices served?
We can prepare and serve the correct statutory notices, liaise with adjoining owners' surveyors, and keep your programme on track.
Need help with compliance?
We manage building control and the legal paperwork on your behalf — from first notice to final certificate.
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