The 18 Parts
Each Part of the Building Regulations explained in plain English.
Part A Structure: Foundations, Walls and Load-Bearing Rules
When you start cutting openings, removing walls or altering roofs, you're in Part A territory. This is the summary that makes Part A easier to use on site.
Part B Fire Safety: What the Regs Actually Require
This summary does NOT replace Approved Document B: Fire Safety — Volume 1: Dwellings (latest edition) or BS 9999 and relevant British Standards.
Part C Damp and Moisture: What Building Control Will Check
Part C is about making sure the site is suitable, keeping contaminants in the ground from harming people, and stopping moisture getting into the building.
Part D Toxic Substances: Cavity Insulation and Fumes
Part D covers cavity wall insulation and the chemicals it releases. When it applies, what your installer must certify, and the paperwork that proves compliance.
Part E Sound Insulation: What You Need Between Dwellings
Part E is about stopping noise passing between homes, between rooms in the same home, and around common areas in blocks and HMOs.
Part F Ventilation: When Do I Need Mechanical Ventilation?
This summary does NOT replace Approved Document F — Volume 1: Dwellings (2021 edition) or the Domestic Ventilation Compliance guidance now folded into it.
Part G Hot Water and Sanitation: Scalding, Storage and Flow Rates
The current Approved Document G sets requirements for cold water supply (wholesome/suitable water) and hot water supply and systems (including unvented).
Part H Drainage: Foul, Surface Water and Soakaways Explained
Part H covers foul drainage, rainwater, and soakaways. What order surface water must go, the rules per property type, and what building control check on site.
Part J Combustion Appliances: Boilers, Stoves, Flues and CO Risk
Part J covers solid fuel stoves and fires, gas and oil boilers, flues and chimneys, hearths, air supply, and fuel storage — plus CO alarms since the 2022 update.
Part K Stairs and Guarding: Heights, Handrails and Fall Protection
The aim of Part K is that people can move between levels without falling, and don't get badly hurt by low sills, big drops, unguarded landings or vulnerable glazing.
Part L Energy Efficiency: What U-Values Do I Need?
For dwellings Part L covers insulation levels, glazing performance, airtightness, heating and hot water efficiency, plus SAP and EPC numbers in the background.
Part M Access: Wheelchair Access and Step-Free Requirements
Category 3 is wheelchair user dwellings (optional, for a percentage of plots where required). This is a summary to make Part M easier to use on site.
Part O Overheating: The New Rules for Homes That Get Too Hot
Part O only applies to new residential buildings (new houses, flats, care homes, student blocks etc.), not extensions or conservatories added later.
Part P Electrical: Do I Need to Notify Building Control?
Part P says electrical work must be designed and installed so people are protected from fire and electric shock. That's the legal test you're working to.
Part Q Security: Door and Window Standards for New Builds
Part Q sets minimum standards for doors and windows in new dwellings so an opportunist burglar can't just lever them open quietly.
Part R Broadband: Gigabit-Ready Infrastructure Requirements
Part R is about making sure new buildings are wired so you can get high-speed internet without ripping the place apart later.
Part S EV Charging: When You Must Install a Charge Point
You must read and follow the full Approved Document S and the DNO or charger manufacturer guidance on load, cabling and protection.
Regulation 7: Materials and Workmanship Standards
Regulation 7 is the Building Regs rule on materials and workmanship that underpins every other Part. What it actually demands and where it trips people up.
Reference Guides
How building control works, which Parts apply, and key contacts.
Asbestos on Domestic Refurbs: What to Do When You Hit It
Rule of thumb: if it's pre-2000 and you're cutting, drilling, grinding or stripping back to structure, you need to think asbestos before you start.
Building Control: How It Actually Works (Step by Step)
This is how the system actually runs so you can work with it, not fight it and then get stitched up when the client tries to sell.
Building Regulations Glossary: Every Term in Plain English
AD (Approved Document) is government guidance showing one way to comply with a specific Part of the Building Regs — not law, but what BC usually work from.
Building Regs vs Planning Permission: What's the Difference?
Some builders mix these up on the edges. Here's the clean split between building regs and planning permission so you can stop arguing and start pointing at it.
CDM 2015 on Domestic Jobs: What Actually Lands on You
CDM 2015 is the Construction (Design and Management) Regulations 2015 — the health and safety law that sits over how construction projects are planned.
Competent Person Schemes: FENSA, NICEIC, NAPIT Explained
They notify the work centrally, BC get told, and the homeowner gets a certificate. It doesn't make the work optional — it changes who signs it off and how.
Conservation Areas and Listed Buildings: Extra Rules That Catch You Out
You need to know when you're in a special area, what extra consents are needed, and where you can't just standard-detail your way out of trouble.
Construction Waste: Your Duty of Care and the Fines If You Get It Wrong
You think you've paid for a skip and the job is done — but if that waste ends up in a lay-by with your invoice in it, the law still points at you.
Do I Need Building Regulations? The Quick Check
Not new builds, loft conversions, big extensions (those are obviously yes). This is where people think "it's only small" and get burned at sale.
Fire Safety Order 2005: What It Means for Your Jobs
Building Regs cover how you build it; the Fire Safety Order covers how it's managed once people are living or working in it.
Future Homes Standard: What's Changing and When
Think of it as: the SAP targets get tougher, gas boilers fade out on new builds, and there's more pressure to prove things are commissioned properly.
Building Regs Key Contacts: Who to Call and When
No fluff — just what each contact is for and how to find them. Statutory Building Control for your area handles notices, inspections and regularisation.
Party Wall Act: What Builders Actually Need to Know
The Party Wall Act is its own law that kicks in on a lot of lofts, extensions and boundary work, and it lives between your client and their neighbour.
COSHH on Construction Sites: What You Actually Need to Do
You don't feel silica dust on the day, but years later it can finish you. HSE are actively targeting dust now, not just helmets and boots.
SuDS and Surface Water: What Actually Matters on Small Jobs
Priority for surface water is soakaway or infiltration, then watercourse, and surface water sewer — only if you can't do the first two.
What Happens If You Don't Comply with Building Regs?
What actually happens when jobs are done off-regs or half-certified — on site, at sale, and with insurers and solicitors in the mix.
Which Building Regs Apply to My Job? The Quick Lookup
A one-page lookup: which Parts of the Building Regs apply to your job. Structural, fire, electrical, heating, and everything else matched to what you're doing.
Working at Height: Ladders, Towers or Scaffold? Which Do I Need?
The straight-talking version of when a ladder is enough, when it isn't, and what HSE actually expect to see when they walk up to your job.
Building Regs by Nation
The guides above cover England & Wales. These sections cover the systems in Scotland and Northern Ireland.
