Glossary of building terms
Building terms in plain English, from permitted development to padstones.
- Permitted development
- Building work that can go ahead without a planning application because national rules already allow it, within set limits.
- Prior approval
- A lighter application where the council checks specific matters, such as neighbours’ amenity, for work that is otherwise permitted development.
- Lawful development certificate
- A certificate from the council confirming that a proposed or completed project is lawful, often used to prove permitted development.
- Householder planning application
- The planning application used for extensions and alterations to a single house.
- Article 4 direction
- A council order that removes some permitted development rights in a defined area, often a conservation area.
- Conservation area
- An area of special architectural or historic interest where extra planning controls apply.
- Listed building
- A building on the national list of special architectural or historic interest; most works need listed building consent.
- Building regulations
- National standards for structure, fire safety, energy, ventilation, drainage and access that building work must meet.
- Building control
- The service that checks building work against the building regulations, run by councils or registered building control approvers.
- Registered building control approver
- A private body registered to carry out building control in England or Wales, an alternative to the council.
- Building warrant
- In Scotland, the approval from the council that must be granted before building work starts.
- Completion certificate
- The document confirming finished work met the building regulations; in Scotland it is submitted to the council for acceptance.
- Full plans application
- A building regulations application where drawings are checked and approved before work starts.
- Building notice
- A simpler building regulations route in England and Wales where work is inspected as it proceeds without approved plans.
- Party wall
- A wall shared between two properties, such as the wall between semi-detached or terraced houses.
- Party wall award
- An agreement drawn up by surveyors setting out how party wall work will be done and how the neighbour’s property will be protected.
- Build-over agreement
- Permission from the water company to build over or near a public sewer.
- Structural engineer
- An engineer who designs and calculates beams, foundations and other load-bearing parts of a building.
- Steel beam (RSJ)
- A rolled steel joist that carries the load of walls or floors above a new opening.
- Padstone
- A block of concrete or engineering brick that spreads the load from a beam into the wall below.
- Acrow prop
- An adjustable steel prop used to support floors and walls temporarily during structural work.
- Lintel
- A beam over a window or door opening.
- Foundation
- The base, usually concrete, that transfers the weight of the building into the ground.
- Trench fill
- A foundation where a trench is filled with concrete almost to ground level.
- Damp-proof course
- A layer built into walls near ground level to stop moisture rising.
- Cavity wall
- An external wall of two leaves of masonry with a gap between, usually filled or partly filled with insulation.
- U-value
- A measure of how much heat passes through a wall, roof, floor or window; lower is better.
- Roof lantern
- A raised glazed structure set into a flat roof to bring daylight into the room below.
- Rooflight
- A window set into the slope of a roof or into a flat roof.
- Dormer
- A box-shaped roof extension with vertical walls and a window, built out from a sloping roof.
- Hip
- A sloping roof end, as opposed to a vertical gable wall.
- Gable
- The vertical triangular wall at the end of a pitched roof.
- Mansard
- A roof with a steep lower slope, typically around 70 degrees, and a flatter upper slope.
- Ridge
- The highest horizontal line of a pitched roof.
- Eaves
- The lower edge of a roof where it overhangs the wall.
- Fascia and soffit
- The boards along the roof edge carrying the gutter (fascia) and closing the underside of the overhang (soffit).
- Head height
- The clear height under a ceiling or roof; about 2.2 m under the ridge is the usual minimum for a loft conversion.
- Protected escape route
- A fire-resisting route, usually the stairway, that lets people leave the building safely in a fire.
- Fire door (FD30)
- A door tested to resist fire for 30 minutes, often required on to the stairs after a loft conversion.
- Cavity drain membrane
- A studded plastic membrane used in basements to direct water to a drain and pump.
- Tanking
- A waterproof coating or membrane applied to walls and floors below ground or in wet rooms.
- Underpinning
- Deepening or strengthening existing foundations.
- Screed
- A levelled layer of sand and cement, or flowing compound, over a floor slab, often containing underfloor heating.
- First fix
- Electrical and plumbing work done before plastering, such as cables, back boxes and pipes.
- Second fix
- The finishing stage after plastering, such as sockets, switches, sanitaryware and doors.
- Snagging
- Checking a finished job for small defects and putting them right before handover.
- Provisional sum
- An allowance in a quote for work that cannot yet be priced exactly.
- Specification
- The written description of materials, products and finishes a price is based on.
- Structural warranty
- Insurance covering defects in a new home, usually for ten years, normally required by mortgage lenders.
- Zero-rated VAT
- VAT charged at 0%, which usually applies to building a new dwelling.