Hiring a tradesperson in the UK quickly becomes an alphabet soup of acronyms. This glossary explains the 47 terms Kent homeowners and landlords most often bump into — certifications (Gas Safe, NICEIC, NFRC, MLA), electrical jargon (EICR, RCBO, Part P), plumbing and heating (CP12, Benchmark, TRV, combi vs system), roofing, building and legal terms that show up in quotes, invoices and contracts. Each entry includes a plain definition, why it matters for you as a homeowner, and a link to the relevant Kent trades listing or hiring guide.
Use the A–Z jump list below to find a term fast, or keep scrolling for the full set.
B
BenchmarkPlumbing & Heating
The industry commissioning record completed by a Gas Safe engineer when a new boiler or hot-water cylinder is installed. Records flow rates, gas pressure, flue analysis and installer details. Why it matters: A completed Benchmark is required for every major manufacturer warranty (Worcester, Vaillant, Baxi). A missing Benchmark is the single most common reason boiler warranty claims are refused.
BenchingBuilding
Reshaping the exposed floor of an old drainage manhole so flows sit in a smooth half-channel rather than a flat concrete base. Why it matters: Poor benching causes sewer blockages and odour. Rebenching is routine during drainage works on Victorian and Edwardian Kent homes.
BS 3621Legal
The British Standard for "thief-resistant" 5-lever mortice deadlocks on timber doors, marked with a kitemark on the faceplate. Why it matters: Most UK home insurance policies require BS 3621 (or equivalent TS007 for uPVC) on all final-exit doors. Non-compliant locks can void theft claims.
Building ControlBuilding
The local authority function (or a private Approved Inspector) that checks work against the Building Regulations. Notifiable work is inspected at key stages and signed off with a Completion Certificate. Why it matters: Without a Completion Certificate (or a competent-person scheme certificate) your work is unregulated, and your solicitor will ask for one when you sell.
Building RegulationsBuilding
The UK statutory minimum standards for building safety, energy, ventilation, fire, accessibility, and more. Grouped into "Parts" (Part A structure, Part B fire, Part L energy, Part P electrical, etc.). Why it matters: Almost any alteration that isn't a simple repair triggers at least one Part of the Building Regulations.
BattenRoofing
A thin strip of treated timber fixed across roof rafters to support tiles or slates. Typical roofing batten is 25×50 mm graded BS 5534. Why it matters: Ungraded or rotten battens fail at 20–30 years; a re-roof always includes new battens, regardless of tile condition.
C
CheckatradeCertification
A paid-membership trade directory that vets insurance and ID and collects customer reviews. Not a regulator and not a qualification — traders pay a monthly subscription for leads. Why it matters: Checkatrade membership is a positive signal but not a guarantee of skill. It's weaker evidence than a sector-specific scheme (Gas Safe, NICEIC, NFRC, MLA).
Combi BoilerPlumbing & Heating
A "combination" boiler that makes hot water on demand directly from the mains, with no hot-water cylinder. Why it matters: Combis suit 1–2 bathroom homes, save space, and are cheaper to install than system boilers. For homes with 3+ bathrooms or large families, a system boiler with a cylinder delivers more usable hot water at peak times.
Consumer UnitElectrical
The fuse board where the incoming mains supply splits into your home's final circuits, now typically a metal-cased unit with RCBO protection per circuit. Why it matters: Old plastic boards with rewireable fuses or dual-RCD layouts fail the 18th Edition spec and are the single most common upgrade on an EICR remedial list.
CP12 (Gas Safety Certificate)Plumbing & Heating
The landlord's gas safety inspection record, issued annually by a Gas Safe engineer, covering every gas appliance, flue and pipework in the property. Why it matters: Landlords must issue a current CP12 to every tenant and retain records for 2 years. Missing or expired CP12s are a common trigger for tenant complaints to the HSE.
CSCS CardCertification
The Construction Skills Certification Scheme card confirms site-level competence and health-and-safety training. Colour-coded by role: Green (labourer), Blue (skilled), Gold (supervisor), Black (manager). Why it matters: Near-universal on commercial sites and a reasonable standards filter for domestic work. A builder whose team has no CSCS cards rarely works on larger professional sites.
D
DNO (Distribution Network Operator)Electrical
The company that owns and operates the local electricity distribution network — in Kent, this is UK Power Networks. Separate from your energy supplier. Why it matters: Any high-load install (EV charger above 3.6 kW, solar, heat pump) requires DNO notification under G98 (fit-and-notify) or G99 (pre-approval) rules.
DPS (Deposit Protection Service)Legal
One of the three government-approved tenancy deposit schemes (alongside MyDeposits and TDS). Since 2007, every AST deposit in England must be protected within 30 days. Why it matters: Failure to protect exposes a landlord to 1–3× the deposit in penalties and blocks Section 21 possession.
E
EICR (Electrical Installation Condition Report)Electrical
A periodic inspection of a property's fixed wiring, resulting in a coded report. Codes: C1 (danger present), C2 (potentially dangerous), C3 (improvement recommended), FI (further investigation). Why it matters: Landlords in England must have a satisfactory EICR every 5 years under the 2020 Regulations; a C1 or C2 must be remedied within 28 days.
EIA (Environmental Impact Assessment)Process
A formal assessment of environmental effects required for certain major development proposals under the Town and Country Planning (EIA) Regulations 2017. Why it matters: Most domestic Kent projects are well below the EIA threshold, but larger barn conversions, rural new builds, and sites within AONB or SSSI often trigger screening.
EPC (Energy Performance Certificate)Legal
A rating of a property's energy efficiency from A (most efficient) to G (least). Valid 10 years. Why it matters: Required for sales, lettings, and most grant schemes. From 2026 proposals, rental properties may need minimum EPC C for new tenancies — check current rules before pricing works.
F
Felt (Roofing)Roofing
Bitumen-saturated fabric sheet used as an underlay on pitched roofs or as the covering on traditional flat roofs. Modern breathable membranes have largely replaced sarking felt. Why it matters: Felt flat roofs last 10–15 years; most Kent homeowners replacing felt in 2026 switch to EPDM rubber (25–35 years) or GRP fibreglass.
FENSACertification
The Fenestration Self-Assessment Scheme — a competent-person scheme for replacement windows and doors. FENSA-registered installers self-certify compliance with Building Regulations Part L and N. Why it matters: A valid FENSA certificate is required on sale and is the easiest evidence that your windows meet the thermal and safety standards.
F-Gas RegulationPlumbing & Heating
UK retained regulation governing fluorinated refrigerant gases used in heat pumps, air conditioning, and commercial refrigeration. Why it matters: Anyone handling refrigerant (installing or servicing a heat pump) must hold F-Gas certification. A heat-pump installer without F-Gas isn't legally allowed to charge or decommission the refrigerant circuit.
FMB (Federation of Master Builders)Certification
The UK's largest builders' trade association. Members are vetted on finance, insurance, and customer references and must follow the FMB code of conduct. Why it matters: Useful quality signal on medium-to-large building work, and FMB-backed contracts (JCT Homeowner / FMB Home Improvement) are a reasonable default for £10,000+ jobs.
G
Gas Safe RegisterCertification
The UK's official gas registration scheme, replacing CORGI in 2009. All operatives working on gas appliances, pipework, and flues must be on the Gas Safe Register. Why it matters: Working on gas without Gas Safe registration is a criminal offence. Always ask for the card and verify the number at gassaferegister.co.uk before any gas work.
G99 (and G98)Electrical
Engineering Recommendations from the Energy Networks Association covering how generators and chargers connect to the distribution network. G98 covers small single-phase connections (fit and notify); G99 covers larger or three-phase connections (apply first). Why it matters: EV chargers above 3.6 kW, solar arrays, and battery storage usually trigger G98 or G99 notifications with the DNO.
H
HMO (House in Multiple Occupation)Legal
A property rented by three or more people from two or more households, sharing a kitchen or bathroom. Large HMOs (5+ occupants) require a mandatory HMO licence in England. Why it matters: HMOs must meet additional fire safety, amenity, and space standards. Tradespeople working on HMOs should understand the extra standards before quoting.
L
LeadworkRoofing
Sheet-lead flashing and covering used around chimneys, parapets, valleys, dormers and tricky roof junctions. Graded by Code number (Code 3 to Code 8 — thicker for exposed positions). Why it matters: Poor leadwork is the leading cause of chimney and junction leaks on Kent homes. Specialist lead workers are worth the premium on Victorian and Edwardian roofs.
M
MCS (Microgeneration Certification Scheme)Certification
A standards and certification scheme for low-carbon technology installers — solar, heat pumps, biomass, solar thermal. Why it matters: Required to access government grants like the Boiler Upgrade Scheme (BUS) £7,500 heat-pump grant and Smart Export Guarantee (SEG) payments for solar. A non-MCS installer cannot get you the grant.
Master Locksmiths Association (MLA)Certification
The UK locksmith trade body. Members are vetted with a criminal record check, skills assessment, annual premises inspection and insurance check. Why it matters: Using an MLA-approved locksmith is the single easiest way to avoid the national call-centre "£49 call-out" scam that has long plagued the trade.
N
NAPITCertification
The National Association of Professional Inspectors and Testers — one of the major electrical competent-person schemes (alongside NICEIC). NAPIT-registered electricians can self-certify Part P notifiable work. Why it matters: Functionally equivalent to NICEIC for homeowners. Look for either on any Part P notifiable job.
NFRC (National Federation of Roofing Contractors)Certification
The main roofing trade body in the UK. Members are vetted on insurance, health-and-safety, financial standing and competence. Offers insurance-backed guarantees on completed works. Why it matters: A strong positive signal on larger roofing jobs. Small one-person roofing firms often aren't NFRC; larger firms and contractors usually are.
NICEICCertification
The National Inspection Council for Electrical Installation Contracting — the UK's oldest electrical competent-person scheme. Registered electricians self-certify Part P notifiable work and issue EICs. Why it matters: Together with NAPIT, the standard qualification to look for on any domestic electrical job. Check the registration at niceic.com before hiring.
O
OZEVCertification
The UK Government's Office for Zero Emission Vehicles, which runs EV-related grant schemes (workplace chargepoint grant, EV infrastructure grant for landlords). Why it matters: For workplace and rental EV-charger grants, the installer must be OZEV-authorised and the chargepoint on the OZEV approved list. The residential homeowner grant ended in 2022 but landlord and workplace grants continue.
P
Part L (Building Regs)Building
The energy-efficiency part of the Building Regulations, covering insulation, heating efficiency, air-tightness, and controls. Significantly tightened in 2022 (Part L 2021). Why it matters: Applies to new boiler installs (minimum SEDBUK rating), extensions (insulation U-values), loft conversions, and window replacements.
Part P (Building Regs)Electrical
The electrical-safety part of the Building Regulations in England and Wales. Notifiable electrical work (new circuits, consumer-unit changes, bathroom/kitchen additions) must be certified by a competent-person scheme electrician or notified to Building Control. Why it matters: Uncertified electrical work delays house sales and can void insurance. Always use a NICEIC/NAPIT registered electrician for notifiable work.
Party Wall AgreementLegal
A legal award made under the Party Wall etc. Act 1996, covering work on shared walls or excavation near a neighbour's structure. Must be served at least 2 months before wall work (1 month for excavation). Why it matters: Ignoring Party Wall Notices is a civil matter — neighbours can seek injunctions to stop the job. Budget £800–£1,500 per surveyor where required.
PAT TestingElectrical
Portable Appliance Testing — a visual inspection and electrical test of plug-in appliances. Not legally required by name, but part of a landlord or employer's duty to keep equipment safe. Why it matters: Commonly requested for furnished rentals and HMOs. A typical portable appliance test costs £1–£3 per item by a competent tester.
Planning PermissionBuilding
Consent from the local planning authority for development that isn't Permitted Development. Managed in Kent by the relevant district council (Maidstone BC, Canterbury CC, Tunbridge Wells BC, etc.). Why it matters: Building without required permission exposes you to enforcement and demolition orders. Always check Permitted Development carefully in AONBs, Conservation Areas, and for listed buildings.
R
RCBOElectrical
A Residual Current Breaker with Overcurrent protection — combines RCD (earth-leakage) and MCB (overload/short-circuit) protection on a single final circuit. Why it matters: Modern 18th Edition consumer units fit an RCBO per circuit so a fault on one circuit no longer takes out half the house. Upgrading from dual-RCD to RCBOs per circuit is a common EICR remedial.
RCDElectrical
Residual Current Device — a safety switch that disconnects a circuit if it detects earth leakage (typically over 30 mA). Cuts power within milliseconds, protecting against electric shock. Why it matters: RCD protection has been mandatory on most circuits in UK homes since the 17th Edition. An old board without any RCD is a Code 2 on an EICR.
Ridge TilesRoofing
The tiles that cap the apex (ridge) where two pitched-roof slopes meet. Traditionally bedded in mortar; modern installs use "dry-ridge" mechanical fixings. Why it matters: Loose or missing ridge tiles are a top cause of storm damage and roof leaks in Kent. Dry-ridge upgrades eliminate the mortar failure point for 40+ years.
S
Skimming (Plastering)Building
The final thin (2–3 mm) plaster coat applied over a backing coat, float coat, or plasterboard to give a smooth finish ready for paint or wallpaper. Why it matters: Quality of the skim is visible for the life of the room. A poor skim requires sanding and multiple mist coats to look acceptable; a good one takes paint perfectly on the first coat.
StopcockPlumbing & Heating
The mains water shut-off valve, usually under the kitchen sink or in a cellar/hallway of older UK homes. Also the external valve in the pavement chamber. Why it matters: Every household should know where the internal stopcock is. In a leak, turning it off fast limits damage. Stiff stopcocks seize when unused — test yours twice a year.
System BoilerPlumbing & Heating
A sealed-system boiler that works with a pressurised hot-water cylinder but no open tanks in the loft. Distinct from a combi (no cylinder) and a heat-only (with tanks). Why it matters: System boilers deliver simultaneous hot-water demand across multiple bathrooms that a combi can't. Best fit for 3+ bathroom homes or where peak demand matters.
T
18th Edition (BS 7671)Electrical
The current UK electrical wiring regulations — formally BS 7671:2018 as amended. Every qualified electrician works to this standard. Why it matters: All new and altered electrical installations in UK homes must comply with the 18th Edition. Consumer-unit replacements now require metal cases and RCBO protection per circuit.
TankingBuilding
Waterproofing applied to a wall, floor, or whole room to prevent water ingress or egress. Common in bathrooms, wet rooms, basements, and retaining walls. Why it matters: Skipped tanking is the root cause of most wet-room and basement damp issues. A tanked wet-room floor should last the life of the tiles; an untanked one fails within 1–3 years.
TDS (Tenancy Deposit Scheme)Legal
One of three government-backed deposit schemes (alongside DPS and MyDeposits) in which all AST deposits must be protected within 30 days of receipt. Why it matters: Unprotected deposits expose the landlord to 1–3× the deposit in penalties and block Section 21 possession. Most letting agents register with one scheme and use it exclusively.
TRV (Thermostatic Radiator Valve)Plumbing & Heating
A valve on each radiator that closes automatically as the room reaches its set temperature. Mandatory on new/replaced radiators under Part L 2022 (except the thermostat-hosting room). Why it matters: TRVs typically pay back in 1–3 years through gas savings and eliminate overheated rooms. Retrofitting is a common Kent plumbing upgrade in older homes.
TrustMarkCertification
A government-endorsed quality scheme for tradespeople. TrustMark-registered firms must belong to a scheme operator that monitors technical and customer-service standards. Why it matters: Required for many government grant-funded schemes (ECO, GBIS). A positive quality signal on general trades, though sector-specific bodies (Gas Safe, NICEIC, NFRC) usually matter more.
TS007Legal
The British standard for Euro-profile lock cylinders on uPVC and composite doors — awarded 1, 2, or 3 stars. A 3-star cylinder resists snapping, picking, drilling, and bumping. Why it matters: Most modern Kent home insurance policies want a 3-star cylinder (or 1-star cylinder plus 2-star handle) on every final-exit door. Older 1-star cylinders can be snapped in under a minute.
Use this with our Kent listings and guides
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