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56 plain-English guides on project basics and the 18 lettered Parts of England’s building regulations. Start with the question that matters to your project.
England only · Sources checked 8 October 2026 · General information, not a project-specific design.
What are building regulations and why do they matter to my project?
Understand why building regulations matter to your extension, loft or chimney removal, how they differ from planning permission and what to arrange before starting.
Read the guidePROJECT BASICSWhat is a building regulations completion certificate and why do I need one?
Learn what a building regulations completion certificate means, how to obtain one, why it matters when selling and what to do if the paperwork is missing.
Read the guidePART A · StructurePart A building regulations explained
Understand Part A building regulations in England, including structural loads, ground movement and why alterations need a clear structural design.
Read the guidePART A · StructureCan I remove a load bearing wall
Find out what to arrange before removing a load bearing wall, from structural design and temporary support to inspections and completion records.
Read the guidePART A · StructureHow deep should extension foundations be
There is no single foundation depth for every extension. Learn how soil, trees, drains and neighbouring buildings affect the design and inspections.
Read the guidePART B · Fire safetyPart B building regulations explained
A simple guide to Part B fire safety in England, covering escape, fire spread, structural protection and the correct edition of Approved Document B.
Read the guidePART B · Fire safetyLoft conversion fire safety explained
Understand how a loft conversion changes fire safety, including escape routes, fire doors, alarms and why the existing floors must also be reviewed.
Read the guidePART B · Fire safetyWhen do you need a fire door
Learn when fire doors may be required, what a complete doorset includes and why installation, glazing and seals matter as much as the door itself.
Read the guidePART C · Site preparation and moisturePart C building regulations explained
Understand Part C requirements for site preparation, contaminated ground and protection against moisture in floors, walls and roofs in England.
Read the guidePART C · Site preparation and moistureDamp proof courses and membranes explained
Learn the difference between a damp proof course and membrane, how they connect and why bridges, thresholds and extension junctions need careful detailing.
Read the guidePART C · Site preparation and moistureDo I need radon protection for an extension
Find out how radon and ground gas risks affect extension design, what information to obtain and why membrane junctions and service penetrations matter.
Read the guidePART D · Toxic substancesPart D building regulations explained
Part D has a narrow role in building regulations. Learn how it addresses toxic fumes from cavity insulation and how it differs from other safety rules.
Read the guidePART D · Toxic substancesIs cavity wall foam insulation safe
Questions to ask before installing cavity wall foam insulation, including product identification, toxic fumes, wall suitability and compliance records.
Read the guidePART D · Toxic substancesDoes Part D cover asbestos and all toxic materials
Understand why Part D is not a general asbestos rule and how cavity insulation, ground contamination and wider material safety need separate checks.
Read the guidePART E · Resistance to soundPart E building regulations explained
Understand Part E sound insulation in England, including separating walls and floors, conversion projects and why construction details affect performance.
Read the guidePART E · Resistance to soundDo I need sound insulation testing
Learn when pre-completion sound testing may be needed, how the Robust Details route differs and what to arrange before new flats or homes are finished.
Read the guidePART E · Resistance to soundHow to improve sound insulation between flats
Understand sound paths between flats, the difference between airborne and impact noise and why a complete wall or floor design beats a single product.
Read the guidePART F · VentilationPart F building regulations explained
A simple guide to Part F ventilation, covering fresh air, extract fans, commissioning and the difference between current and published 2026 guidance.
Read the guidePART F · VentilationDo replacement windows need trickle vents
Understand when replacement windows need background ventilation and why trickle vent decisions depend on the existing home and its ventilation system.
Read the guidePART F · VentilationBathroom and kitchen extractor fans explained
Learn how bathroom and kitchen extract fans fit a ventilation system, why duct routes and airflow matter and what to check before installation.
Read the guidePART G · Water and sanitationPart G building regulations explained
Understand Part G water supply, hot water safety, sanitation and water efficiency, with practical questions to ask when planning bathrooms and kitchens.
Read the guidePART G · Water and sanitationWhat is the water efficiency limit for new homes
Understand the 125 litre and optional 110 litre water efficiency standards for new homes, how calculations work and why fittings must match the design.
Read the guidePART G · Water and sanitationHot water safety and the 48 degree bath limit
Learn what the 48 degree bath-water provision means, why cylinder storage temperature is different and what to ask about hot water safety controls.
Read the guidePART H · Drainage and waste disposalPart H building regulations explained
A simple guide to Part H drainage, covering foul water, rainwater, sewers and waste storage, with advice on planning routes before building an extension.
Read the guidePART H · Drainage and waste disposalCan I build an extension over a sewer
Find out what to check before building over or near a sewer, including pipe ownership, undertaker agreement, maintenance access and structural details.
Read the guidePART H · Drainage and waste disposalHow should an extension drain rainwater
Understand rainwater drainage for an extension, including infiltration, soakaways, other discharge routes and why roof gutters are only part of the design.
Read the guidePART J · Combustion appliancesPart J building regulations explained
Understand Part J combustion appliance safety, including air supply, flues, carbon monoxide alarms, building protection and fuel storage arrangements.
Read the guidePART J · Combustion appliancesDo I need approval to install a wood burning stove
Learn what to arrange before installing a wood burning stove, including building regulations, the flue, hearth, air supply and certification route.
Read the guidePART J · Combustion appliancesWhen is a carbon monoxide alarm required
Understand the Part J carbon monoxide alarm provision, its exception for appliances solely for cooking and why an alarm never replaces safe installation.
Read the guidePART K · Falling collision and impactPart K building regulations explained
Understand Part K protection from falls, collision and impact, including stairs, guarding, glazing and safe operation of windows and doors.
Read the guidePART K · Falling collision and impactStaircase building regulations explained
Learn what a staircase design needs to show, including rise, going, pitch, headroom, landings and guarding, before ordering stairs for a loft or extension.
Read the guidePART K · Falling collision and impactWhere is safety glazing needed
Understand safety glazing in doors, low windows and other critical locations, and why the complete glass assembly and guarding role must be checked.
Read the guidePART L · Energy performancePart L building regulations explained
Understand Part L energy performance in England, including insulation, glazing, services and the published 2026 guidance that generally starts in March 2027.
Read the guidePART L · Energy performanceCan an extension have large areas of glazing
Understand the Part L approach to glazing in extensions, the common 25 percent allowance and why larger areas may need a justified calculation route.
Read the guidePART L · Energy performanceWhen do the 2026 building energy rules start
The 2026 energy guidance is published, but the rules generally start in March 2027. Learn the key dates and why transition checks must be project specific.
Read the guidePART M · Access and usePart M building regulations explained
Understand Part M access and use requirements, the three dwelling categories and why non-domestic buildings have a different accessibility approach.
Read the guidePART M · Access and useDoes a house extension need wheelchair access
Find out why an ordinary house extension does not automatically need a new-home wheelchair layout and what existing access and design checks still matter.
Read the guidePART M · Access and useAccessible toilet requirements explained
Understand accessible toilet design under Part M, including usable space, door operation and the separate role of Part T toilet accommodation.
Read the guidePART O · OverheatingPart O building regulations explained
Understand Part O overheating requirements for new residential buildings, the available assessment routes and why glazing and ventilation must be coordinated.
Read the guidePART O · OverheatingDoes Part O apply to an extension
Learn why Part O normally concerns new residential buildings and why summer comfort still deserves attention when designing a glazed house extension.
Read the guidePART O · OverheatingHow can large windows avoid overheating
Learn how orientation, shading, ventilation and realistic opening assumptions affect overheating in a new home with large windows or extensive glazing.
Read the guidePART P · Electrical safetyPart P building regulations explained
Understand Part P electrical safety in homes, including compliance, notification, competent person schemes and the certificates to keep after electrical work.
Read the guidePART P · Electrical safetyWhich electrical work must be notified
Learn the main categories of notifiable domestic electrical work in England and why kitchens, bathrooms and existing circuits need careful distinction.
Read the guidePART P · Electrical safetyWhat electrical certificates should I receive
Understand electrical installation certificates, minor works certificates and building regulations records, and why an EICR is not automatically a substitute.
Read the guidePART Q · SecurityPart Q building regulations explained
Understand Part Q security for new dwellings, including relevant doors and windows, conversions and why a strong lock alone does not prove compliance.
Read the guidePART Q · SecurityWhat makes doors and windows Part Q compliant
Learn what to check when buying Part Q doors and windows, including evidence for the complete assembly, hardware, glazing and installation details.
Read the guidePART Q · SecurityDoes Part Q apply to replacement windows
Understand why ordinary replacement windows in an existing home do not automatically trigger Part Q and which other building regulations still need checking.
Read the guidePART R · Broadband infrastructurePart R building regulations explained
Understand Part R broadband infrastructure, the different rules for new dwellings and other work, and why ducts and network connections are separate issues.
Read the guidePART R · Broadband infrastructureDo new homes need gigabit broadband connections
Understand the Part R gigabit connection requirement for new dwellings, the 2000 pound cost cap and why a fallback still needs evidence and infrastructure.
Read the guidePART R · Broadband infrastructureDoes Wi Fi satisfy Part R
Learn why Wi-Fi equipment does not replace Part R broadband infrastructure, and what to check about entry points, service routes and future network installation.
Read the guidePART S · Electric vehicle chargingPart S building regulations explained
Understand Part S electric vehicle charging infrastructure, the different project categories and why parking, renovation scope and exceptions matter.
Read the guidePART S · Electric vehicle chargingDo new homes need electric car charge points
Learn how Part S applies to new homes with associated parking, why the number of spaces matters and what to check before accepting charger specifications.
Read the guidePART S · Electric vehicle chargingDo major renovations need EV charging provision
Find out how major renovation and parking conditions affect Part S, and why residential and commercial projects need different charging assessments.
Read the guidePART T · Toilet accommodationPart T building regulations explained
Understand Part T toilet accommodation in England, its non-domestic scope, exemptions and how it works alongside accessibility and sanitation requirements.
Read the guidePART T · Toilet accommodationSingle sex and universal toilets explained
Understand the difference between single sex and universal toilets under Part T, including enclosure, handwashing and the conditions for space-limited layouts.
Read the guidePART T · Toilet accommodationDoes Part T replace accessible toilet rules
Learn why Part T does not replace Part M accessible toilet requirements and how to coordinate toilet types, numbers, sanitation and usable space.
Read the guideNo matching guides. Try a shorter phrase, such as “fire”, “loft” or “drainage”.