Home Improvement Glossary
An A–Z guide to building, plumbing, electrical and home improvement terms — explained in plain English so you can understand quotes, specifications and conversations with your tradesperson.
A
- Aggregate
- Coarse material (gravel, crushed stone) mixed with cement and water to make concrete. Used in foundations, driveways and structural work.Learn more →
- Architrave
- Decorative moulding fitted around door and window frames to cover the join between the frame and wall. Available in MDF, softwood and hardwood.Learn more →
- Artex
- Textured coating applied to ceilings and walls, popular in the 1970s–80s. Pre-2000 artex may contain asbestos — always test before disturbing.Learn more →
B
- Batten
- Thin strip of wood used to support roof tiles, create stud walls, or provide a fixing surface for cladding and plasterboard.Learn more →
- Bonding Coat
- A base plaster layer applied to walls before the skim finish coat. Provides a key for the finish plaster to adhere to.Learn more →
- BS 7671
- The IET Wiring Regulations — the national standard for electrical installations in the UK. All domestic wiring must comply with the current 18th Edition.Learn more →
- Building Regulations
- Legal standards set by local authorities that building work must meet. Cover structural integrity, fire safety, energy efficiency, ventilation and drainage. Separate from planning permission.Learn more →
C
- Cavity Wall
- A wall made of two skins (leaves) of brickwork with an air gap between them. The cavity can be filled with insulation to improve energy efficiency.Learn more →
- Consumer Unit
- Also called a fuse board — the main electrical distribution board in a home. Modern units use RCDs and MCBs for circuit protection.Learn more →
- Combi Boiler
- A combination boiler that provides central heating and instant hot water without a separate water tank. The most common boiler type in UK homes.Learn more →
- CP12
- The Gas Safety Certificate — a legal requirement for landlords. A Gas Safe engineer must inspect all gas appliances, flues and pipework annually.Learn more →
D
- DPC (Damp Proof Course)
- A horizontal barrier in a wall (usually at ground level) that prevents moisture rising from the ground into the building fabric. Can be physical or chemical.Learn more →
- DPM (Damp Proof Membrane)
- A waterproof sheet laid under concrete floors to prevent ground moisture penetrating upwards. Essential in all new builds.Learn more →
- Dormer
- A structural extension that projects from a sloped roof, creating additional headroom and floor space in a loft conversion.Learn more →
- Dry Lining
- Fixing plasterboard directly to walls (with adhesive dabs or battens) instead of wet plastering. Faster and less messy than traditional plastering.Learn more →
E
- EICR
- Electrical Installation Condition Report — a detailed inspection of a property's electrical system. Required for rental properties every 5 years since 2020.Learn more →
- EPDM
- Ethylene Propylene Diene Monomer — a durable rubber membrane used for flat roofing. Lifespan of 30–50 years with minimal maintenance.Learn more →
- Escrow
- A financial arrangement where a third party holds payment until work is completed satisfactorily. TradeMatch uses escrow to protect both homeowners and tradespeople.Learn more →
F
- Fascia Board
- A horizontal board fixed to the lower edge of a roof, supporting the guttering. Usually UPVC, timber or aluminium.Learn more →
- First Fix
- The initial stage of building work — plumbing pipes, electrical wiring, stud walls and joists installed before plastering. Not visible in the finished building.Learn more →
- Flashing
- Strips of lead, zinc or plastic used to waterproof joints in a roof — especially where the roof meets a wall, chimney or skylight.Learn more →
G
- Gas Safe Register
- The official registration body for gas engineers in the UK. It is illegal for anyone not on the Gas Safe Register to carry out gas work. Always check your engineer's Gas Safe ID card.Learn more →
- GRP
- Glass Reinforced Plastic (fibreglass) — used in flat roofing, bay roof canopies and door canopies. Durable, waterproof and low-maintenance.Learn more →
H
- Hip Roof
- A roof where all sides slope downward to the walls. A hip-to-gable conversion extends the hip end to create a vertical wall, maximising loft space.Learn more →
- Hot Water Cylinder
- An insulated tank that stores heated water for domestic use. Found in system and regular boiler setups but not with combi boilers.Learn more →
I
- Isolation Valve
- A small tap that shuts off the water supply to an individual appliance (tap, toilet, washing machine) without turning off the whole house.Learn more →
J
- Joists
- Horizontal structural timbers or steel beams that support a floor or ceiling. Floor joists typically span between load-bearing walls.Learn more →
K
- K-Rend
- A brand of silicone-based external render. Self-cleaning, breathable and available in a wide range of colours and textures.Learn more →
L
- Lintel
- A horizontal support (steel, concrete or stone) above a door or window opening that carries the weight of the wall above.Learn more →
- LVT
- Luxury Vinyl Tile — a durable, waterproof flooring that mimics stone or wood. Popular for kitchens, bathrooms and high-traffic areas.Learn more →
M
- MCS Certification
- Microgeneration Certification Scheme — required for solar panel and heat pump installers. MCS certification is necessary for homeowners to claim the Boiler Upgrade Scheme grant.Learn more →
- Monocouche
- A single-coat, through-colour external render applied in one pass. Quicker than traditional two-coat rendering but requires skilled application.Learn more →
N
- Noggin
- A short horizontal timber fixed between studs or joists to provide rigidity and a fixing point for heavy items like radiators or TV brackets.Learn more →
O
- OZEV
- Office for Zero Emission Vehicles — the government body that manages EV charger grants. OZEV-approved installers are required for grant-funded installations.Learn more →
P
- Party Wall
- A wall shared between two properties. The Party Wall etc. Act 1996 requires you to serve notice on neighbours before certain building works affecting shared walls.Learn more →
- Permitted Development
- Building work that can be done without planning permission, subject to limits on size, height and location. Most single-storey rear extensions qualify under PD rights.Learn more →
- Power Flush
- A process that cleans central heating systems by pushing water and cleaning chemicals through radiators and pipes at high velocity to remove sludge and debris.Learn more →
R
- RCD
- Residual Current Device — a safety device in your consumer unit that instantly cuts power if it detects an electrical fault, preventing electric shock.Learn more →
- Repointing
- Removing old, damaged mortar from between bricks and replacing it with fresh mortar. Essential for weatherproofing and structural integrity.Learn more →
- RSJ
- Rolled Steel Joist — a steel beam used to support structural loads, typically installed when removing a load-bearing wall.Learn more →
S
- Second Fix
- The finishing stage after plastering — fitting sockets, switches, radiators, door handles, skirting and architrave. The visible elements of the finished build.Learn more →
- Skim
- A thin (2–3mm) finishing coat of plaster applied over plasterboard or an existing surface to create a smooth, paintable finish.Learn more →
- Soakaway
- An underground drainage structure that disperses surface water into the surrounding soil. Required for driveways and hard surfaces that block natural drainage.Learn more →
- Soffit
- The underside of a roof overhang — the horizontal board between the fascia and the house wall. Often includes ventilation holes for roof airflow.Learn more →
T
- Tanking
- Waterproofing a basement or cellar by applying a waterproof coating or membrane to walls and floors to prevent water ingress.Learn more →
- TRV
- Thermostatic Radiator Valve — a self-regulating valve fitted to radiators that controls room temperature by adjusting hot water flow. Required on all radiators except in rooms with a room thermostat.Learn more →
U
- Underlay
- A material layer laid between the subfloor and floor covering (laminate, carpet, vinyl) for insulation, soundproofing and cushioning.Learn more →
V
- Valley
- The internal angle where two sloping roof surfaces meet. Valleys channel rainwater and are prone to leaks if flashing or lead lining fails.Learn more →
W
- Wet Room
- A fully waterproofed (tanked) bathroom where the shower drains directly into the floor. Requires specialist tanking and gradient work.Learn more →
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