Annealed (glass)
Ordinary glass that has not undergone any process to make it a safety glazing material.

Anti-slam
Device that prevents spontaneous closure of a window.

Anti-sun glass
Glass with special coating that reflects heat and glare from the sun without reducing light levels - available in a choice of tinted finishes.

Arch
Shaped or curved top (window or door).

Architrave / quadrant / d mould
Internal PVCu trim.

Argon gas
Inert gas sometimes used in the cavity of a double glazed unit to aid thermal insulation.

Asymmetric
Not symmetrical - general reference to friction hinge.

Bars
Window 'bars' that form decorative stripes and rectangles, ie as in Georgian bar.

Bay pole
Reinforcing metal pole used in load bearing bay window installations.

Bay projection
Distance that a bay protrudes from an external wall.

Bay window
Window structure that protrudes from house - either in an arc or rectangular plan.

Beading
Moulded plastic strip that retains glazing unit or door panel.

Bell end
End of a Victorian conservatory containing frames set at an angle.

Bevels
Designs cut into glass at a 'bevel' or angle.

Bolt
Bar or rod that slides into a socket.

Box sash
Traditional sash window.

Bow window
Window structure that protrudes from house in an arc on a flat external wall.

BBA
British Board of Agrément - controlling body for building product standards.

BPF
British Plastics Federation.

BSI
British Standards Institute.

BS EN ISO 9002
Commercial operating standards of high quality.

Casement
An outward opening window.

Centre deadlock
Door and window locking device.

Cill (internal / external)
Flat PVCu projection at the bottom of a frame.

Colour overlays
Modern technique that mimics stained glass in windows.

Cockspur
Handle that latches onto a catch on a window.

Combination (victorian/edwardian)
Refers to conservatory usually comprising of period type and lean-to design.

Conservatory
Glazed domestic building normally attached to dwelling.

Crestings
Ornate trim running along the top of a conservatory.

Double-hung sash
Sash window with moving top and bottom sections. Single-hung versions have a fixed top or bottom section.

Dormer window
Projecting window that is built into a roof to provide headroom in a converted loft.

Double glazing
A unit of two pieces of glass joined by edge spacers and sealed to make a sandwiched, air tight gap.

Dummy sash / vent
Sash profile fixed to a frame to look as if it is an opener. Dwarf wall A low perimeter wall, usually constructed from brick.

End cap
A finishing cap, covering a cut end piece of window cill or similar profile.

Espagnolette
A sliding pinion, that locks into a striker plate on the window or door frame.

Etched glass
Glass, chemically treated to give it an obscure opaque finish - generally decorative.

Eurogroove
Channel incorporated in PVCU profile to accept hardware and mechanisms.

External bead
Bead securing glass in frame accessible from outside, therefore removable from outside.

Exit hinge (90)
Opens window to 90 degree, allowing unimpeded exit in case of emergency. Also allows for easy cleaning of both sides of window.

Fascia
Board running along the length of a roof on the end of the roof spars.

Fenestration
The arrangement of windows in a building.

Fire egress (egress, exit hinge)
Window that conforms to current fire safety standards, and can be used as an emergency exit.

Finial
Ornate spike at the peak of a conservatory.

Flipper gasket
Used as a bubble gasket on doors.

Flush coupler
Profile used to join two outer frames together whilst having load bearing properties.

Frame anchors
Screw within a nylon rawl-plug used to fasten frame to brick work.

French door
Double, hinged, opening doors Ð normally fully glazed.

Friction hinge
High security type hinge with asymmetric action.

• Bubble gasket - Cushioned seal between sash and window.
  
  
• Co-ex(truded) gasket - Seal between glazing panel and beading.
  
  
• Glazing gasket - Seals double glazed unit.

GGF
Glass and Glazing Federation.

Glass
Hard, brittle, translucent or transparent, non-crystalline solid.

Glass packer
Small pieces of plastic used whilst glazing a window to ensure double glazed unit rests properly in frame. Glass-to-ground Panels of glass from floor to roof.

Glazier
Person who fits glass.

Glazing bars
Narrow moulding used to divide an area of glass into smaller panes.

Glazing beads
Narrow moulding used to hold glass securely in its frame.

GWPP
Georgian wired polished plate. Type of glass containing wired mesh.

GWRC
Georgian wired rough cast. As above with obscure glass.

Heavy outer
Outer frame 72mm thick.

High security glazing unit
Comprising an external sheet of laminated glass and an internal sheet of toughened glass. Preferably in an internally beaded frame.

Hipped roof
A roof with all sides sloping.

Hook bolt
Hook shaped bolt that slides into and up, gripping a profiled plate in the surrounding frame.

Installation
Site where windows, etc. have been or will be installed.

Internal beading
Bead securing glass in frame from the inside - not accessible from the outside.

I - plus
Type of low emissivity glass.

I section
Thin piece of profile used to join the outer frame of two windows.

Leaded tight
Glazed part of a window that is decorated with leading.

Leaded window
Lead stripes are used to create a decorative pattern on a window - e.g. rectangles, diamonds, etc. Mimics technique of joining glass by lead strip. Used also in conjunction with colour overlays.

Locking wedge
2 PVCU wedges located on the hinge side of an opener to aid efficient location.

Low E
Glass that allows radiant heat from the sun to pass through, but reflects household heat back into the room.

Low threshold (aluminium or PVCu)
Thin profile or aluminium strip used at the bottom of a door sash for easy wheelchair access, etc.

Midrail
Heavy PVCU profile running horizontally in doors and sidescreens.

Mullion
PVCU profile running vertically between outer to outer frame, or outer to horizontal transom.

Mishandling device
Mechanism to prevent tilt and turn mechanism working both ways simultaneously.

Moulded glass
Glass with a moulded surface decoration. Used as purely decorative or to obscure the view through.

Multi-chamber
Method of constructing PVCU window frames with air gaps between inner and outer frames to provide superior insulation.

Multi-point locking
System of locks that operates along full length of a door or window frame.

Mushroom bolt
Broad head diameter bolt use in espagnolette locking.

Night vent
Slightly open, secondary window locking position for ventilation.

Outer frame
Profile that makes up the outside edge of a frame.

Outside view
The way a window drawing is seen from.

Pilkington K
Type of low e high insulation glass. See 'Low E'.

Pitch
Angle at which roof is set.

Polycarbonate
An opaque lightweight modern plastic used as a roofing material. Twin-and triple-wall polycarbonate have multi-layer constructions which provide superior levels of thermal insulation.

Plaster reveal
Thickness of internal plaster lining to which frame will abut.

Profile
PVCU or aluminium extrusions that make the frame, casement, cills and bars of window and door units.

PVC
Polyvinyl Chloride. A synthetic thermoplastic material made by polymerising vinyl chloride - used in many window and door components.

PVCu
Unplasticised version of Polyvinyl Chloride.

Reinforcement
Metal inserts into window and door profiles where ultimate strength is needed.

Residential door
Exterior domestic door.

Restrictor hinge
Hinge that restricts window opening as a safety factor for small children.

Reverse butt weld
Manufacturing process necessary to produce fully welded, internally beaded windows.

Sash
The part of a window that can be opened for ventilation.

Sash cord
Cord connecting sash weight to sliding sash.

Sash window
Window of two sashes arranged so that they can slide past each other in a vertical configuration.

Scotia bead
Ornate bead, often concaved.

Sealed unit
Hermetically (airtight) sealed glazing that consists of two layers of glass with an air gap between them.

Secondary glazing
Glazed frame fitted to the internal of existing frames.

Security glazing beads
Narrow moulding to prevent glazing being removed from its frame.

Soffits
Underside of barge board or fascia.

Spacer bar
Flat aluminium tube that separates two panes of glass in a double glazed unit.

Shootbolt
Bolt that 'slides' into a striker plate on the surrounding frame .

Sidescreen
Fixed full window to the side of a residential, French or patio door.

Silica gel
Compound that absorbs moisture, damp, etc.

Silicone sealer
Waterproof sealing compound.

Stay
Locking device on wooden window frames, used to hold a hinge window in an open position for ventilation.

Striker (plate)
The mechanism a bolt locks into.

Square drive
Standard square section shaft, operating lock mechanisms and handles.

Swept arch
Decorative panel that creates a decorative arch on glazing.

Thermal break
A physical barrier between external and internal temperatures. In PVCU, a thermal break is achieved with a multi-chamber construction.

Tie bars
Horizontal bars fastening opposing roof bars of a conservatory roof.

Tilt and turn hinge
Ingenious mechanism that allows a window to open inwardly with one action and to tilt to a locked position with a further action.

Tilt plate
Mechanism that allows tilt action of 'tilt and turn' window.

Toe and heel
Method of packing for glazing of doors or side hung vents.

Top-hung
Top-Hung window sashes are hung from hinges fixed along the top horizontal edge of the window opening.

Top light
Narrow height opening or fixed glazed panel above door or main window.

Transom
PVCU profile running horizontally between outer to outer frame, or outer to vertical mullion.

V - notch
Detail cut into point of weld.

Wall plate / ring beam
Plate from which roofing bars are attached for conservatory roofs.