Renovation Glossary

Clear definitions of renovation and construction terms, written for homeowners.

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Aggregate

Granular materials such as crushed stone, gravel, or sand that are mixed with cement and water to make concrete or used as a sub-base beneath foundations and floors.

Air Tightness

How well a building prevents uncontrolled air leakage through gaps, cracks, and holes in its structure — affecting energy efficiency, comfort, and moisture control.

Architrave

The decorative moulding fitted around a door or window frame to cover the joint between the frame and the wall.

B

Backsplash / Splashback

A protective wall covering installed behind a kitchen counter or bathroom sink to guard against water damage and staining.

Bespoke / Custom

Made to order for your specific requirements and measurements, rather than selected from a standard range of sizes or designs.

Bifold Doors

A set of door panels connected by hinges that fold back against each other in a concertina fashion, designed to open up an entire wall between indoor and outdoor spaces.

Bill of Quantities

A document listing all the materials, labour, and quantities needed for a renovation project, used to get accurate and comparable quotes from contractors.

The local authority department (or approved private inspector) responsible for checking that renovation and building work complies with building regulations — the safety and quality standards required by law.

Building Envelope

The physical barrier between the interior and exterior of a building — including walls, roof, windows, doors, and floors — that protects against weather, heat loss, and moisture.

Building Permit

Official approval from a local government authority (US) required before starting construction, renovation, or demolition work, ensuring the project meets local building codes and safety standards.

Building Regulations

UK statutory standards that set minimum requirements for the design, construction, and alteration of buildings, covering structural safety, fire safety, energy efficiency, and accessibility.

C

Cabinet Carcass

The basic box structure of a kitchen or bathroom cabinet — the sides, top, bottom, and back — before doors, drawers, and hardware are fitted.

Certificate of Completion

An official document issued by building control confirming that renovation or construction work has been inspected and complies with building regulations.

Certificate of Occupancy

An official document issued by a local government confirming that a building or renovated space meets all applicable codes and is safe and legal to occupy.

Change Order

A formal written document that modifies the original scope of work, price, or timeline of a renovation contract, agreed by both homeowner and contractor.

Combi Boiler

A combination boiler that provides both central heating and hot water on demand from a single unit, without the need for separate hot water cylinders or cold water tanks.

Composite Decking

An outdoor decking material manufactured from a blend of wood fibres and recycled plastic, designed to look like natural timber while requiring less maintenance.

Consumer Unit / Fuse Box

The main electrical distribution panel in a UK home that divides the incoming electricity supply into separate circuits, each protected by a circuit breaker or fuse.

Contingency

A budget reserve — typically 10-20% of the project cost — set aside to cover unexpected expenses that arise during a renovation.

Cost-Plus Contract

A renovation contract where you pay the actual cost of labour and materials plus an agreed percentage or fixed fee as the contractor's profit.

Coving / Crown Moulding

A curved or decorative moulding fitted where a wall meets the ceiling, softening the junction and adding a finished look to a room.

D

Dado Rail / Chair Rail

A horizontal moulding fixed to a wall at roughly chair-back height, originally designed to protect plaster from furniture damage and now used as a decorative feature.

Damp-Proof Course (DPC)

A horizontal moisture barrier built into the walls of a building, usually near ground level, to prevent rising damp — moisture from the ground travelling upward through masonry.

Day Rate

A daily charge for a tradesperson's labour, used as an alternative to a fixed project price — common for smaller jobs or work where the scope is hard to define upfront.

Defects Liability Period

A set period after a renovation is completed (typically 6-12 months) during which the contractor is obliged to return and fix any defects at no additional cost.

Demolition

The controlled removal of existing structures, walls, or fixtures during a renovation project, carried out safely and in compliance with local regulations.

Dot and Dab

A method of fixing plasterboard to walls using blobs of adhesive rather than screws or nails, commonly used for dry lining interior walls.

Double Glazing

A window or door construction featuring two panes of glass separated by a sealed air or gas-filled gap, providing significantly better thermal and acoustic insulation than single glazing.

Dry Lining

A method of finishing interior walls by attaching plasterboard to them without using wet plaster, often used to add insulation or create a smooth surface quickly.

E

En-Suite

A bathroom directly connected to and accessible only from a bedroom, providing a private bathing and washing area for that room's occupants.

Engineered Wood Flooring

A flooring product made from a real hardwood top layer bonded to a stable plywood or softwood base, offering the look of solid wood with improved dimensional stability.

EPC (Energy Performance Certificate)

A rating that shows how energy-efficient a property is, graded from A (most efficient) to G (least efficient), required when selling or renting a property in the UK.

Extractor Fan

A mechanical ventilation fan installed in kitchens, bathrooms, and utility rooms to remove excess moisture, odours, and stale air.

Extractor Hood / Range Hood

A ventilation unit mounted above a cooktop or hob that removes cooking fumes, steam, smoke, and odours from the kitchen through filtration or ducting to the outside.

F

Fascia

A long board running along the lower edge of a roof, fixed to the ends of the rafters, where gutters are typically attached.

First Fix

The rough installation phase of a renovation where plumbing pipes, electrical wiring, and structural carpentry are installed behind walls and under floors — before plastering and finishing.

Fixed-Price Contract

A renovation contract where the total cost is agreed upfront before work begins, giving homeowners cost certainty regardless of how long the work takes.

Flashing

Thin strips of metal or other waterproof material installed at joints and junctions in a roof to prevent water from seeping into the building structure.

Flat-Pack

Furniture or cabinets supplied as individual panels and components, packaged flat for transport and assembled on site during installation.

Formwork

Temporary moulds or frames, usually made from timber or plywood, used to hold wet concrete in shape while it sets and gains strength.

Freeholder

The person or entity that owns the land and the building on it outright, with no time limit on their ownership. In a block of flats, the freeholder owns the building while leaseholders own the right to occupy individual flats.

G

General Contractor

A professional who manages and coordinates a renovation or construction project, hiring and overseeing subcontractors, sourcing materials, and ensuring work is completed to specification.

Grout

A cement-based or epoxy paste used to fill the gaps (joints) between tiles after they are laid, providing a sealed, finished surface.

H

Handleless Kitchen

A kitchen design style where cabinets and drawers open without traditional handles, using push-to-open mechanisms, recessed channels (J-pull or C-channel), or integrated finger pulls.

HOA (Homeowners Association)

A governing body in a residential community — such as a condo complex, townhouse development, or planned neighborhood — that sets and enforces rules about property modifications, maintenance, and shared spaces.

HVAC

An abbreviation for Heating, Ventilation, and Air Conditioning — the systems that control a building's temperature, air quality, and humidity.

I

Induction Hob / Induction Cooktop

A type of cooktop that uses electromagnetic fields to heat compatible pans directly, rather than heating a surface beneath the pan.

Insulation

Material installed in walls, floors, roofs, and lofts to reduce heat loss from a building, improving energy efficiency and comfort.

Integrated Appliance

A kitchen appliance designed to be installed behind matching cabinet doors so it blends seamlessly with the rest of the kitchen cabinetry.

J

Joist

A horizontal structural beam, usually timber or steel, that supports a floor or ceiling and spans between walls or other supports.

K

Kitchen Island

A freestanding or fixed kitchen unit that stands independently from the wall-mounted cabinets, providing additional worktop space, storage, and often seating.

L

Leaseholder

A person who owns the right to live in a property (typically a flat) for a fixed number of years, as granted by the lease, but does not own the building or land itself.

Lintel

A horizontal structural beam placed above a door or window opening to support the weight of the wall above and transfer it to the sides of the opening.

Listed Building

A building in the UK that has legal protection due to its special architectural or historic interest, requiring Listed Building Consent for most alterations — including internal changes.

Load-Bearing Wall

A wall that supports the structural weight of the building above it — such as upper floors, the roof, or other walls — and cannot be removed without alternative structural support.

LVT (Luxury Vinyl Tile)

A synthetic flooring material made from PVC layers that realistically mimics the appearance of natural wood or stone, offering durability and water resistance.

M

Making Good

Repairing and finishing surfaces such as walls, floors, and ceilings after construction, plumbing, or electrical work has been carried out.

P

Party Wall

A wall shared between two adjoining properties — such as the dividing wall between semi-detached or terraced houses — with specific legal implications when renovation work affects it.

Party Wall Agreement

A legal agreement between neighbouring property owners required before carrying out renovation work that affects a shared (party) wall, governed in the UK by the Party Wall etc. Act 1996.

PC Sum (Prime Cost Sum)

A budget allowance included in a quotation for items you have not yet selected, such as tiles, fixtures, or fittings, so the contractor can provide a total price.

Permitted Development

A set of building works and changes you can carry out in the UK without needing to apply for planning permission, subject to specific conditions and limits.

Planning Permission

Formal approval from a local planning authority (UK) required before carrying out certain types of building work, changes of use, or alterations to the external appearance of a property.

Plasterboard / Drywall

A sheet building material made from a gypsum core sandwiched between paper liners, used to create smooth walls and ceilings.

Pointing

The visible mortar joints between bricks or stones in external walls — and the process of repairing or renewing those joints when they deteriorate.

Practical Completion

The point at which a renovation project is substantially finished and ready for the homeowner to use, even if minor snagging items remain.

Preliminary Costs

The overhead and setup costs a contractor charges for running a renovation project, separate from the actual construction work — such as site setup, scaffolding, skip hire, and project management.

Provisional Sum

An estimated allowance included in a quotation for work that cannot be accurately priced in advance, covering both materials and labour.

Q

Quartz Worktop / Quartz Countertop

An engineered stone kitchen surface made from approximately 90-95% crushed natural quartz bound with polymer resin, offering a durable, non-porous, and low-maintenance work surface.

Quotation

A formal written document from a contractor stating the fixed price they will charge to complete a specified scope of work, including materials and labour.

R

RCD (Residual Current Device)

An electrical safety device that monitors the flow of current and instantly cuts the power if it detects a fault that could cause electric shock or fire.

Rebar (Reinforcing Bar)

Steel bars placed inside concrete to add tensile strength, preventing cracking and structural failure under load.

Rendering

A protective and decorative coating applied to external walls, covering the underlying brickwork or blockwork with a smooth, textured, or patterned finish.

Retention

A percentage of each payment (typically 5-10%) withheld by the homeowner until the renovation is fully complete and any defects have been fixed.

Retrospective Planning Permission

An application for planning permission submitted after building work has already been carried out, used to regularise development that was done without the required approval.

Right to Light

A legal right, established through long use, to receive natural light through windows — which a neighbour's building work must not significantly obstruct.

Roof Window / Velux

A window installed in a sloped roof to bring natural light and ventilation into attic, loft, or top-floor rooms. Often referred to by the brand name Velux, the market leader.

RSJ (Rolled Steel Joist)

A steel beam — typically I-shaped — used to provide structural support when load-bearing walls are removed during a renovation, allowing open-plan layouts.

S

Sash Window

A traditional window style consisting of one or two panels (sashes) that slide vertically within a frame, commonly found in Georgian, Victorian, and Edwardian properties.

Scope Creep

The gradual, often unplanned expansion of a renovation project beyond its original scope, typically leading to increased costs and extended timelines.

Scope of Work

A detailed written description of all the work to be carried out in a renovation project, including materials, specifications, and deliverables.

Screed

A thin layer of cement-based material applied over a concrete subfloor to create a smooth, level surface for final floor finishes.

Second Fix

The finishing phase of a renovation where visible fixtures and fittings are installed — sockets, light fittings, taps, toilets, door handles, and skirting boards — after plastering is complete.

Service Charge

Regular payments made by leaseholders towards the maintenance, repair, and management of the building and its shared areas, such as hallways, roofs, and gardens.

Shaker Kitchen

A kitchen style featuring doors with a flat recessed centre panel surrounded by a simple raised frame, inspired by the clean-lined furniture of the American Shaker community.

Silicone Sealant

A flexible, waterproof sealant applied around baths, showers, sinks, and other wet-area junctions to prevent water from penetrating behind surfaces.

Skim Coat

A thin layer of finishing plaster applied over plasterboard or existing plaster to create a smooth, paint-ready surface.

Skirting Board / Baseboard

A board that runs along the base of an internal wall where the wall meets the floor, protecting the plaster and providing a decorative finish.

Snag List / Punch List

A list of minor defects, unfinished items, or work that does not meet the agreed standard, compiled near the end of a project and resolved before final payment.

Snagging

The process of inspecting completed renovation or construction work to identify defects, unfinished items, or work that doesn't meet the agreed specification.

Soffit

The underside of a roof overhang, or a boxed-in section inside a home used to conceal pipes, ductwork, or structural elements.

Soil Pipe

A large-diameter pipe (typically 110 mm / 4 inches) that carries toilet waste from the property to the underground sewer or septic system.

Specification (Spec)

A detailed written description of the materials, products, finishes, and standards to be used in a renovation project, ensuring everyone agrees on exactly what will be delivered.

Splashback / Backsplash (Tile)

A protective wall covering installed behind a kitchen hob, cooktop, or sink to shield the wall from water, grease, and cooking splashes.

Stopcock

The main shut-off valve that controls the flow of mains water into a property, allowing you to turn off the entire water supply in an emergency or for maintenance.

Strip Out

Removing existing fixtures, fittings, and finishes from a space before renovation work begins, leaving a blank canvas for the new design.

Stud Wall

A non-load-bearing internal wall built from a frame of timber or metal studs, clad with plasterboard on each side.

Subcontractor

A specialist tradesperson or company hired by a general contractor to carry out a specific part of a renovation project, such as plumbing, electrical, or tiling.

T

Tanking

A waterproofing treatment applied to walls and floors below ground level — such as basements and cellars — to prevent water ingress from the surrounding soil.

Thermal Bridge / Cold Bridge

A point in a building's structure where heat passes through more easily than the surrounding area, creating a cold spot that can lead to condensation and mould.

Three-Phase Power

A higher-capacity electrical supply that delivers power through three alternating currents, used in homes with large electrical demands such as heat pumps, EV chargers, or commercial-grade equipment.

Threshold / Transition Strip

A strip or bar fitted at a doorway to create a neat transition between two different flooring surfaces or levels.

Tongue and Groove

A method of joining wooden boards where a protruding ridge (tongue) on one board fits into a corresponding slot (groove) on the next, used for flooring, wall cladding, and ceiling panelling.

U

Underfloor Heating

A heating system installed beneath the floor surface that warms rooms from the ground up, using either hot water pipes (wet system) or electric cables (dry system).

Underlay

A layer of material installed beneath flooring to provide cushioning, sound insulation, thermal insulation, and moisture protection.

V

Vapour Barrier / Vapor Barrier

A sheet material installed within walls, floors, or roofs to prevent moisture from passing through the building structure, reducing the risk of damp and mould.

Variation

A change to the original agreed scope of work, price, or timeline during a renovation project, which should be documented in writing before the work is carried out.

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