Automatic Door Glossary: Terms Explained

Access control: A system that decides who can open a door and when, using card or fob readers, keypads, intercoms or timers. On an automatic door it switches the operator between open access and controlled entry, usually with free exit from the inside. See access control for automatic doors.
Activation sensor: The sensor that tells an automatic door to open, usually mounted above the door on each side. It detects people approaching and starts the opening cycle. It is separate from the safety sensors that stop the door closing on someone, although one combined device can do both jobs.
Active infrared sensor: A sensor that sends out invisible infrared light and measures what is reflected back, so it can detect a person or object in a set area even when they are standing still. Active infrared is widely used for presence detection and safety on sliding and swing doors.
Approved Document M (England): Government guidance on access to and use of buildings in England. Volume 2, for buildings other than dwellings, says a powered door should be used where a self-closing entrance door would need more than 30 N at the leading edge to open in the first 30 degrees, or more than 22.5 N from 30 to 60 degrees. Wales has its own Approved Document M, which uses 20 N.
Battery backup: A rechargeable battery in or beside the operator that keeps an automatic door working, or lets it make a final safe movement such as opening fully, when the mains power fails. It is common on doors on escape routes and useful at home where getting in and out during a power cut matters.
Bi-parting door: A sliding door with two leaves that open from the middle, one to each side. It gives a wide opening and a quick cycle, and is the most common automatic door at shop, office and hospital entrances. See automatic sliding doors.
Bottom track: A rail along the floor that a sliding door runs in. Most automatic sliding doors do not have one, because the leaves hang from the track in the header and are kept in line by small floor guides. That keeps the threshold level for wheelchairs, buggies and trolleys and avoids a slot that collects dirt and causes trips.
Break-out (BEO): A feature that lets the sliding leaves of an automatic door, and often its side screens, be pushed outwards like swing doors in an emergency, giving a wide way out. Break-out doors are used where an automatic sliding door is on an escape route. See break-out escape route doors.
BS 7036-0: BS 7036-0:2014 is the UK code of practice for risk assessment and risk reduction at power-operated pedestrian doors. It is used alongside BS EN 16005 and is written for building owners and occupiers as well as installers. The older 1996 parts of BS 7036 were withdrawn when it was published.
BS EN 16005: The British and European standard for the safety in use of power-operated pedestrian doors. The current edition is BS EN 16005:2023+A1:2024, which replaced the withdrawn 2012 edition. It covers design, safety devices and testing for sliding, swing, folding and revolving doors. Standards are not law in themselves, but it is the recognised benchmark for showing a door is safe. See our guide to BS EN 16005.
Carriage and rollers: The carriages are the hangers that carry each sliding leaf from the track in the header, running on rollers or wheels. Worn rollers make a door noisy, sticky or prone to jumping off its track, and they are among the parts most often replaced at a service or repair.
Clear opening width: The usable width of a doorway when the door is fully open, measured between the leaves, frame or anything that sticks out. It decides whether a wheelchair, bed or trolley can pass. Guidance expects at least 1000 mm for public entrance doors in new buildings in England and Wales, and an 800 mm clear opening for an accessible entrance door in Scotland.
Closing edge: The edge of a door leaf that leads as the door closes, where it meets the frame, another leaf or a fixed screen. It is the main point where someone can be struck or trapped, which is why it is protected by presence sensors, safety edges or low-energy movement.
Crushing, shearing, impact and drawing-in hazards: The main ways a powered door can injure someone. Crushing is being squeezed between the door and a fixed part, shearing is a cutting action between parts moving past each other, impact is being struck by the moving leaf, and drawing-in is a hand or clothing being pulled into a gap. A risk assessment checks each one.
Curved sliding door: An automatic sliding door whose leaves and screens follow a curve, forming a half-round or full-round entrance. The curved glass and track are made to the radius of the entrance. Curved doors are often used at hotels, offices and shopping centres. See curved automatic doors.
Declaration of Conformity: A signed document in which the manufacturer of a machine declares that it meets the safety law that applies to it. A powered door is treated as machinery, so whoever puts a new or converted automatic door into service, which can be the installer, should provide one at handover with instructions and the correct marking.
Detection zone: The area a sensor watches. An activation sensor's zone is in front of the door, where people approach, and a presence sensor's zone covers the space the door moves through. Zones are adjusted on site so the door opens in time and stays safe without opening needlessly.
Disabled Facilities Grant: A means-tested grant that can help pay for adaptations so a disabled person can get into and around their home, which can sometimes include a door opener. It is available in England and Wales through councils and in Northern Ireland through the Housing Executive. Scotland has no Disabled Facilities Grant; councils help through their Scheme of Assistance. Approval is needed before work starts.
Draught lobby (vestibule): A space between two sets of doors at an entrance, so one set can close before the other opens. It cuts draughts and heat loss at busy entrances and can improve security at reception. See automatic entrance lobbies.
Electric lock: A lock that is locked and released electrically, controlled by the door operator, access control or fire alarm. Electromechanical locks move a bolt or latch, often inside the operator of a sliding door. Magnetic locks hold the door shut with an electromagnet and release when the power is cut. On escape routes, locks are chosen and wired so they release when needed.
Escape route: A route people use to get out of a building safely in an emergency, as set out in its fire strategy. Automatic doors on an escape route need special arrangements, such as failing safely to open or breaking out, so they never block the way out. See automatic doors on escape routes.
Fail-safe and fail-secure: Fail-safe means a door or lock goes to its safe state, usually open or with the lock released, if the power is lost or a fault is detected. Fail-secure means it stays locked when the power is lost. Doors and locks on escape routes are normally fail-safe, while fail-secure locks suit doors where security comes first and escape is provided another way.
Fire alarm interface: The connection between the building's fire alarm and an automatic door, hold-open device or electric lock. When the alarm operates, the interface tells each door to do what the fire strategy requires: open and stay open, close, or release its lock. It is tested at handover and as part of routine fire safety checks.
Floor guide: A small guide fixed to the floor, or to the side screen, that keeps the bottom of a sliding leaf in line and stops it swinging. It runs in a groove or channel along the bottom of the leaf. A worn or missing floor guide lets the leaf move when it is pushed, which can damage the door.
Frameless glass door: An automatic sliding door whose leaves are toughened or laminated glass held by small patch fittings or rails, with no full frame around each leaf. The operator sits in a slim header, giving an all-glass look. See frameless glass automatic doors.
Free-swing door closer: A fire door closer that lets the door move freely, as if no closer were fitted, so it is easy to open, and then closes the door when the fire alarm operates or the power fails. It is often used on bedroom doors in care homes, where residents may find a normal closer too heavy.
Full-energy operator: A swing door operator that opens and closes the door at normal speed, suitable for busy doors. Because it moves with more force, it needs safety sensors, such as presence sensors on both sides of the door, to stop or slow the door when someone is in its path. See low-energy or full-energy operators.
Hazard zone: A place where a moving door could injure someone, such as between a sliding leaf and a side screen, on the hinge side of a swing door or in the closing gap. The risk assessment identifies each hazard zone and how it is protected, whether by safe distances, guards, low force or sensors.
Header (transom): The horizontal section above an automatic sliding door that houses the operator, track, carriages and control unit behind a removable cover. It needs a sound structure to fix to, which is one of the first things checked at a survey. On framed doors it forms the top of the frame and is sometimes called the transom.
Hermetic seal: A seal around a sliding door that closes it airtight, or nearly so, so that air pressure, temperature and cleanliness on each side can be controlled. Hermetic doors press onto their seals as they close and are used for operating theatres, isolation rooms, laboratories and cleanrooms. See hermetic sliding doors.
Hold-open device: A device that holds a fire door open in normal use and releases it to close when the fire alarm operates or the power fails. It can be a wall or floor magnet or built into the door closer. Fire doors that are held open must close automatically when the alarm sounds. See fire door hold-open devices.
Hold-open time and opening speed: Hold-open time is how long an automatic door stays open before it starts to close; opening speed is how fast it moves. Both are set on site to suit the people using the door, with slower speeds and longer hold-open times for older or disabled users and quicker cycles at busy entrances.
Light curtain: A row of infrared beams, often in the side posts or along the leaf edge, that detects anything breaking the beams in the opening. It is used to stop a door closing on someone in the doorway and is common on sliding doors and as extra protection on swing doors.
Low-energy operator: A swing door operator that moves the door slowly and with low force, so it is less likely to injure someone it touches. It is used only where a risk assessment shows a low risk to vulnerable users, usually on doors that are not in frequent use, and the door can normally be opened by hand as well. See accessible door operators.
Manifestation: Markings on clear glass in doors and screens that make the glass obvious, so people do not walk into it. Guidance in England and Scotland places manifestation in two bands, between 850 mm and 1000 mm and between 1400 mm and 1600 mm above the floor. It can be a logo, pattern or strip.
Motion sensor (microwave or radar): An activation sensor that detects movement using microwave radar and opens the door when someone approaches. It can be set to react only to movement towards the door, so people walking past do not open it. It cannot detect someone standing still, so it is usually paired with a presence sensor.
Opening area (swing door): The area a swing door sweeps through as it opens. Anyone standing there, or approaching from that side, could be struck, so it is covered by a presence sensor or low-energy movement, and push pads are placed outside it. When open, the door should not project into a busy route.
Operator (drive unit): The motor, gearbox, control unit and drive that move an automatic door. On sliding doors it sits in the header and drives the leaves along a track; on swing doors an arm pushes or pulls the door. Replacing a worn operator can keep the existing frame and leaves. See drive unit replacement.
Partial opening (winter mode): A setting that opens a sliding door to only part of its full width for everyday traffic, cutting draughts and heat loss in cold weather. Depending on how it is set up, the door can still open fully when needed, for example when a wheelchair user presses a button or for deliveries.
Planned preventive maintenance: Servicing booked at regular intervals to keep a door working and safe, rather than waiting for it to break down. No law sets a fixed interval; it is set by the manufacturer's instructions and how heavily the door is used. We recommend a trained engineer checks the safety functions at least once a year. See automatic door servicing.
Power-assisted door: A door that opens by hand but has a motor that reduces the effort needed, or an operator that can run in a power-assisted mode. It suits people who can push a light door but not a heavy one. Building regulations guidance in England expects low-energy powered swing doors to work in manual, powered and power-assisted modes.
Presence sensor: A sensor that detects a person or object standing still in the door's path or in the area it moves through. It stops a closing door, or stops it starting to close, while someone is there. Presence detection is the main safety device on most modern automatic doors.
Programme switch: The selector that sets how an automatic door behaves. Typical modes are automatic (two-way traffic), exit only, permanently open, closed or night (locked) and partial opening for winter. It is usually key-operated or code-protected so only staff can change the mode, and a separate key switch can open or lock the door on its own.
Push pad: A large button, usually marked with a wheelchair or door symbol, that opens an automatic door when pressed with a hand, fist or elbow. Building regulations guidance in England, Wales and Scotland places manual controls between 750 mm and 1000 mm above the floor, set back so the opening door does not hit the user.
Radio push button: A wireless push button or fob that sends a coded radio signal to the door operator. It can be fixed anywhere without running a cable, carried by a resident or wheelchair user, or mounted on a wheelchair, so the door can be opened from a short distance away.
Reasonable adjustment: A change a service provider or employer makes so disabled people are not put at a substantial disadvantage, such as altering a heavy entrance door. The duty comes from the Equality Act 2010 in England, Wales and Scotland, and from the Disability Discrimination Act 1995 in Northern Ireland. An automatic door is a common adjustment, but fitting one does not on its own mean every duty is met.
Revolving door: A door with two, three or four wings turning inside a round drum under a canopy, so the entrance is never fully open to the outside. It cuts draughts at busy entrances. A revolving door is not accessible on its own, so an accessible swing or sliding door should be provided alongside it. See revolving doors.
Risk assessment: A site-specific look at who uses a door, how it is used and what could hurt someone, followed by the measures that reduce each risk. For automatic doors it follows BS 7036-0 alongside BS EN 16005 and should take account of children, older people and disabled people. It is reviewed when the door or its use changes. See safety inspections.
Safety edge: A pressure-sensitive strip on the edge of a door leaf that detects contact with a person or object and signals the operator to stop or reverse. It is one of the ways a powered door can be prevented from trapping someone, and is often used alongside presence sensors.
Service report: The written record left after a service, repair or inspection visit. It lists the checks made, the condition of the door and its safety devices, any faults found and any work recommended. Keeping these reports is the usual way to show a door is being maintained and kept in good working order.
Side-screen protection: Measures that protect people where a sliding leaf moves past a fixed glass screen or wall, a gap that can trap fingers and hands. Protection can be a safe distance, a physical guard such as a rail or brush, or a sensor that stops the door when someone is in the zone.
Single-slide door: A sliding door with one moving leaf that slides to one side of the opening. It suits entrances with wall space on only one side, or where a narrower opening is enough, such as an internal corridor or a smaller shop. See automatic sliding doors.
Technical Booklet R (Northern Ireland): The guidance on access to and use of buildings that supports Part R of the Building Regulations (Northern Ireland) 2012. Separately, those regulations require a powered door or gate to have a means to prevent it trapping anyone and a means to open it if the power fails.
Technical file: The records a manufacturer keeps to show a machine meets safety law: drawings, the risk assessment, component details, test results and instructions. For an automatic door assembled or converted on site, the installer may take on the manufacturer's duties, including compiling the technical file and making it available if asked.
Technical Handbook (Scotland): The guidance that explains how to meet the Building (Scotland) Regulations 2004. Section 4 of the non-domestic handbook covers accessible entrances and powered doors, including a clear opening of at least 800 mm for an accessible entrance door, where push pads go and what a powered door on an escape route must do if the power fails.
Telescopic sliding door: A sliding door with two or more leaves on each moving side that stack behind each other as they open. It gives a wider clear opening than a standard sliding door where there is little wall beside the opening. See telescopic sliding doors.
Test body: A standard-shaped object used to check that a door's safety sensors detect what they should, sized to represent parts of a person, including a small child. Engineers place it in the hazard zones during commissioning and inspection to prove the door stops, slows or reverses as it should.
Toothed belt: The reinforced rubber belt with teeth that links the motor to the carriages on most automatic sliding doors, pulling the leaves open and closed. Belts stretch and wear with use, so their tension and condition are checked at every service and they are replaced when worn.
UKCA and CE marking: Conformity markings showing that a product meets the safety law that applies to it. In Great Britain, machinery such as an automatic door can carry either the UKCA or the CE marking, as CE recognition has been extended indefinitely. In Northern Ireland, machinery carries the CE marking, with UKNI added where a UK body carried out the assessment.
Wave switch: A touch-free switch that opens a door when a hand is waved a short distance in front of it. It reduces shared touch points in healthcare, food and washroom settings and avoids the door opening for people who are only walking past. See touch-free and push-button activation.

Automatic door glossary

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