London Building Regulations 2024

Building regulations ensure that construction work in London meets minimum standards for health, safety, energy efficiency, and accessibility. Whether you're planning an extension, loft conversion, basement development, or comprehensive renovation, understanding and complying with building regulations is mandatory. This guide explains the key regulations affecting North London homeowners in 2024, covering recent changes and practical compliance requirements.

What Are Building Regulations?

Building regulations are legal requirements set out in the Building Act 1984 and Building Regulations 2010 (as amended). They apply to most building work in England, including:

• Extensions and new buildings
• Loft and basement conversions
• Structural alterations
• Installation of heating systems, windows, electrics
• Drainage and sanitation
• Fire safety improvements

Regulations are organised into Approved Documents (Parts A-S), each covering specific aspects of building work.

Key Approved Documents for Home Renovations

Part A - Structure: Ensures buildings are structurally safe:

• Foundation design and construction
• Load-bearing walls and beams
• Structural calculations for extensions and alterations
• Requirements for underpinning and basement work

Part B - Fire Safety: Critical for loft conversions and extensions:

• Fire escape routes and protected stairways
• Fire-resistant doors and construction
• Smoke alarms on all floors
• Escape windows from loft bedrooms
• Stricter requirements for three-storey+ homes

Part C - Moisture Resistance: Prevents damp and water damage:

• Damp-proof courses and membranes
• Waterproofing for basements
• Protection from rain penetration
• Condensation control and ventilation

Part F - Ventilation: Ensures adequate air quality:

• Background ventilation (trickle vents in windows)
• Purge ventilation (openable windows)
• Extract ventilation in kitchens and bathrooms
• Mechanical ventilation with heat recovery (MVHR) for airtight buildings

Part G - Sanitation: Covers bathrooms, kitchens, drainage:

• WC, bathroom, and kitchen facilities
• Hot water supply and safety
• Drainage and waste disposal
• Water efficiency (maximum 125 litres per person per day)

Part H - Drainage: Foul and surface water systems:

• Connection to sewers or septic systems
• Surface water disposal (soakaways, drains)
• Protection from surcharging

Part J - Heating and Hot Water: Efficiency and safety:

• Boiler efficiency requirements
• Heating controls (thermostats, timers, zone controls)
• Insulation of pipes and hot water cylinders
• Carbon monoxide detectors where required

Part K - Protection from Falling: Stairs, balconies, windows:

• Staircase design (rise, going, handrails)
• Balcony and balustrade heights (1100mm minimum)
• Window safety and restrictors
• Level changes and trip hazards

Part L - Conservation of Fuel and Power: Energy efficiency:

• Insulation standards (walls, roofs, floors)
• Glazing performance (U-values)
• Airtightness requirements
• Heating system efficiency
• Updated significantly in 2021/2022 for improved energy performance

Part M - Access: Accessibility requirements:

• Accessible entrances where practical
• Ground floor WC requirements for extensions
• Door widths and circulation space
• Level or gently sloping thresholds

Part P - Electrical Safety: Electrical installations:

• Most electrical work must be certified
• Notifiable work requires building control or registered electrician
• Consumer unit (fuse box) location and design
• Bonding and earthing requirements

Building Control Approval Process

Two routes to building control approval exist:

1. Local Authority Building Control:

• Apply through your local council (Camden, Barnet, Haringey, Westminster, etc.)
• Submit plans and calculations
• Pay fixed fees (£300-£1,200 depending on work scope)
• Council inspectors visit at key stages
• Completion certificate issued when approved
• Timeline: 4-8 weeks for approval, inspections during work

2. Approved Inspector (Private Building Control):

• Private companies offering building control services
• Often faster and more flexible than council
• Competitive fees
• Same legal status as council approval
• Popular for larger projects

Full Plans vs. Building Notice

Full Plans Application:

• Submit detailed drawings and calculations before work starts
• Council reviews and approves (or requests changes)
• Provides certainty before starting work
• Required for complex projects
• Recommended for extensions, lofts, basements
• Fee: £200-£800 depending on project size

Building Notice:

• Submit basic details, work out compliance during construction
• Quicker to start
• Less certainty—may require changes mid-project
• Suitable only for simple, straightforward work
• Cannot be used for certain work types
• Fee: £150-£600

For home extensions and conversions, Full Plans route recommended—provides clarity and avoids costly mid-project changes.

Key Inspection Stages

Building control inspectors visit at critical stages:

1. Commencement: 2 days' notice before work starts
2. Foundation Excavation: Before concrete poured
3. Foundation Concrete: After pouring, before covering
4. Damp-Proof Course: Before building above DPC
5. Oversite/Floor Slab: Hardcore, membrane, insulation before concrete
6. Drains: Before covering
7. Pre-Plastering: All first-fix work visible (electrics, plumbing, insulation)
8. Final: All work complete and compliant

Failure to request inspections at proper stages can require demolition and reconstruction for inspection.

Recent Changes (2021-2024)

Part L (Energy Efficiency) - June 2022:

• Significantly higher insulation standards
• U-values reduced (better insulation required)
• Improved airtightness requirements
• Better glazing standards
• More efficient heating systems mandatory
• Aimed at reducing carbon emissions

Part S (EV Charging) - June 2022:

• New builds and major renovations require EV charging points
• Cable routes for future installation where immediate installation not feasible
• Applies to properties with parking

Part F (Ventilation) - June 2022:

• Updated ventilation requirements
• Better standards for indoor air quality
• MVHR systems increasingly common

Common Non-Compliant Work

Issues frequently identified:

• Missing Insulation: Extensions not meeting Part L standards
• Inadequate Structural Support: Beams undersized or poorly installed
• Fire Safety Failures: Missing fire doors, inadequate escape routes in loft conversions
• Poor Drainage: Incorrectly installed drains and waste pipes
• Electrical Work: Non-certified electrical installations
• Inadequate Ventilation: Missing extractors or trickle vents
• Glass Safety: Non-safety glass in critical locations

Consequences of Non-Compliance

Working without building control approval or failing inspections causes serious problems:

• Legal Issues: Council can serve enforcement notice requiring work removal
• Sale Problems: Buyers' solicitors require building control certificates
• Mortgage Issues: Lenders reluctant to lend on non-compliant properties
• Insurance: Home insurance may be invalid for unapproved work
• Safety Risks: Non-compliant work may be unsafe
• Retrospective Approval: Expensive and sometimes impossible to obtain

Regularization Certificates

For work completed without approval, regularization possible:

• Apply to building control for retrospective approval
• Inspection of completed work
• May require opening up walls, floors for inspection
• Fees typically double normal building control fees
• Not guaranteed—some work cannot be approved retrospectively
• Indemnity insurance alternative if regularization not possible

Working with Building Control

Making the process smooth:

• Apply early—don't start work before approval
• Use experienced contractors familiar with regulations
• Request inspections at correct times
• Keep good communication with inspector
• Address any concerns promptly
• Maintain site access for inspections
• Don't cover work before inspection

Costs and Timeline

Building Control Fees (Local Authority):

• Small extension/loft conversion: £400-£800
• Large extension: £800-£1,200
• Basement conversion: £1,000-£1,500
• Whole house renovation: £1,200-£2,000

Timeline:

• Full Plans approval: 5-8 weeks
• Inspections: Schedule 48 hours in advance
• Final certificate: 2-4 weeks after completion