Air infiltration: Industry test that measures the amount of air leakage through a window or door (the lower the number the better).
Apron: Decorative trim positioned directly underneath a window stool and installed flush against the wall
Arch window: 4 sided unit with a curve at the top
Art glass: Decorative glass in a variety of colors/shapes/patterns used to accent a window or door
Astragal: Center post of a double door attached to the fixed or inactive door panel
Awning window: A window hinged at the top the sash swings outward from the bottom.
Balancer: Counter-weight mechanism to assist raising or lowering of a double-hung or single-hung sash
Bay window: Window consisting of three or more units that angle out beyond the wall; often configured with a large center unit and two flanking units
Bow window: Window consisting of three or more units projecting out from wall to form a radius
High Altitude Capillary Breather Tubes: Very small diameter tubes placed within the unit that allows equalization of the air space due to high elevation pressure differences.
Brick mould: Exterior trim around the window frame traditionally used to attached the window to the wall
Casement window: A window hinged on either side the sash opens horizontally opposite the hinge.
Casing: Flat, decorative molding used on the interior perimeter of a window or door that covers the space between the unit and rough opening or between units
Check rail: Located on double-hung windows where the bottom sash and top sash meet and the lock/keeper is mounted
Circle Top™ (Half Round) window: Half circle unit consisting of a curved top and linear bottom
Cladding: Low maintenance covering or coating attached to the unit exterior to protect it from the elements
Clear opening area: The size of the opening created when a unit is in a full open position
Clerestory: Window located up high on wall; typically unreachable from ground level
Coil stock: Roll aluminum that is bent into shape to form a transition piece between the unit exterior and siding/trim
Condensation Resistance: Condensation Resistance (CR) measures how well a window resists the formation of interior condensation. CR is expressed as a number between 1 and 100. The higher the number, the more resistant to condensation formation. Condensation Resistance ratings are determined under specific laboratory conditions. Actual condensation performance is a function of temperature, humidity and air movement as well as other uncontrolled, site specific factors.
Combination unit: Storm window and insect screen contained in a single frame
Condensation: Water that collects as droplets on the glass/sash/panel interior or exterior under certain conditions (typically cold surfaces when exposed to humidity).
Conversion kit: Retrofit kit to add tilting capability to 1968 and newer Andersen® Perma-Shield® Narroline® windows
Cornice: An ornamental molding at the top of the window positioned above the exterior trim
Cottage window: Double-hung window where the upper sash is shorter than the bottom sash
Design Pressure: Pressure (measured in pounds per square foot-psf) required by building codes to meet windload requirements. Our product "PG" -Performance Grade rating is used to determine compliance.
Direct glazed/ direct set: Glass is directly glazed into frame; stationary unit
Double-hung: Venting upper and lower sash in a single frame that slide vertically past one another
Dowel joint: A corner joint created by precisely boring matching holes into a door rail and style and joining them together with a dowel pin
Drip cap: One piece aluminum or vinyl cover installed above windows/doors that directs water away from the top of the unit
Dual pane/Double pane glass: Two panes of uncoated (non-Low-E) glass with an air-filled cavity (not argon-blend gas-filled)
Egress window: A venting window large enough to be used as an emergency exit. Check local codes for egress requirements in your area.
ENERGY STAR®: A government-backed program to help consumers identify energy efficient products.
Equal lite: Window or door with equal spaced grille bars
Escutcheon plate: Decorative door handle plate that conceals the locking mechanism
Extension jamb: Wood component fastened to the interior of the window/door that extends the window frame out to the wall depth
Exterior trim: A decorative trim positioned around the exterior perimeter of a window or door
Extruded aluminum: Aluminum that is shaped by running it through a die, typically more durable than roll-formed material
Fenestration: Refers to any opening in a structure filled with a window, door or skylight.
Fibrex® material: Exclusive to Andersen, its a composite of wood fiber and PVC polymer thats 2x stronger than vinyl.
Fixed/Stationary: Non-venting or non-operable
Flashing: Water resistant material that directs water away from your windows
Flexiframe®: Andersen brand name for fixed geometric windows shapes (octagon, pentagon, trapezoid)
Folding door: Door unit with multiple hinging panels that can be folded together to create an large, unobstructed opening
Foot lock: Auxiliary lock used on gliding doors to secure the operating panel to the sill
Frame: Outer structure of a window or door that holds the sash or panel in position
French casement window: Unit with two venting sash that open outward to provide a large center opening with no center post
French door: Hinged door(s) with large glass area surrounded by a wide wood side stiles and a tall bottom rail
Full divided light: Grille intended to replicate the look of a True Divided Light unit; consists of an interior grille, exterior grille and spacer between the glass panes
Full frame: Frame intended for installation direct to the rough opening; opposite of insert window
Glazing: Glass in a window sash or door panel; the act of installing glass in a window sash or door panel
Glazing bead: Wood or vinyl pieces around the perimeter of the glass that covers the space between the glass edge and sash/panel
Gliding door/sliding door: Door with two or more panels where one panel slides horizontally past another
Gliding window/sliding window: Window with two sash, where one sash slides horizontally past the other
Grilles/Muntins/Dividers/Bars/Grids: Components used to simulate individual pieces of glass within a sash/panel
Grilles-Between-the-Glass (GBG's)/Finelight™: Grille bars that are placed between the glass panes; allows for easy cleaning
Gusset plate: Metal plate attached to a window or door to strengthen a window or door joint
Half insect screen: Insect screen that only covers the lower sash area of a double-hung windows
Handing: Opening direction of hinging windows and doors; direction is determined by location of hinge on unit as viewed from exterior
Head board/Seat board: Stain grade wood shaped to the angles of a bay or bow window that form the finished upper and lower interior surfaces
Header: Heavy beam extended across the top of the rough opening to divert the weight of the wall or roof around the window
Impact Resistant glass: Laminated glass frequently used in hurricane-prone areas for protection from wind-borne debris
Insect screen: A tightly woven mesh attached to a frame; allows outside air ventilation while keeping insects out
Insert window: A new window unit intended to be installed inside the frame pocket of an existing window
Insulating glass unit: Two or more glass panes that are sealed together to increase energy efficiency
Jalousie window: Louvered window with multiple horizontal glass sections that rotate open or closed
Jamb: Window or door frame members that form the top and sides of a unit
Jamb clips: Metal brackets used to secure a unit to the rough opening from the interior
Jamb liner: Interior frame cover surface where the sash slide on double-hung window
J-channel: Receiver components that surrounds a window intended to hide the seam between the window and siding
Keeper: Receiver on a sash that the lock engages
Keyed lock: Patio door lock that enables locking and unlocking from the home's exterior
Laminated glass: Layered glass that resists breakage and holds together when broken
Laminated Veneer Lumber (LVL): Engineered wood consisting of multiple layers of thin wood bonded together
Lift: Handle on the bottom of a double hung window that makes it easier to raise/lower the sash
Light/Lite: Individual glass panes within a window sash or door panel
Lock: Mechanism used to secure windows and doors into a closed position
Low-E glass: Glass with a low-emissivity coating that restricts heat loss
Masonry opening: Opening in a brick, stone or stucco wall where a window or door is installed
Measurement guide: Step-by-step tool to help in determining the dimensions of replacement windows
Meeting stile: Central location on a gliding window or door where the sash/panel overlap
Monolithic glass: Laminated glass that has no air space; used in specific situations such as some coastal applications
Mortise-and-tenon: Strong wood joint made by fitting together a slot (mortise) in one board and the matching projecting member (tenon) on the adjoining board
Mulling: Joining of two or more window or door units together; joint can run vertically, horizontally or both
Mullion: The vertical or horizontal joint between individual window or door units that form a combination
Multi-point lock: Lock that engages the sash or panel in multiple locations; activated by a single motion
Nailing flange / Installation flange: Narrow attachment strip on the window perimeter that typically used to secure the window to the rough opening and provide added protection from water infiltration
NFRC: National Fenestration Rating Council is an non-profit organization that provides for fair, accurate and credible energy performance ratings for windows, doors & skylights.
Obscure glass: Glass with a texture of pattern of various degrees of opacity that limits visibility through a window or door (see also patterned glass)
Operator: Metal arm, gear and handle used to open and close hinged windows
Outdoor/Indoor Transmission Class (OITC): Measurement standard used to indicate the rate of sound transmission between indoors and outdoors (see also STC)
OX / XO: "OX" or XO" are used to identify the opening direction of gliding windows/doors; "X" stands for operating while "O" stands for stationary
Palladian window: Large, arch-top window flanked by smaller windows on each side
Panel: Refers to the rail, stile and glass assembly on a door; similar to a window sash
Panning kerf: Narrow groove on the exterior outer frame edge of a unit typically used to accept trim or aluminum coil stock
Parting stop: A narrow frame molding that holds a sash or panel in position
PassiveSun™ glass: Andersen brand name for a glass type ideal for situations where solar heat gain is desired, typically in passive solar building designs.
Passive panel/sash: Panel/sash that will open only after active panel/sash is opened
Patterned glass:Glass than lets in light while obscuring vision (see also Obscure glass)
Performance Grade (PG): An industry rating for a unit that has been tested for air, water, structural and force entry performance. Used to determine compliance with code required design pressures.
Perma-Shield®: Andersen brand name for low-maintenance exterior cladding
Plinth block: Decorative wood block typically found at the top corners of the unit that creates a transition from vertical to horizontal interior trim
Pocket door: A door panel that can be concealed by a wall; panels slide into wall
Pre-finished: Factory painted or stained unit that is ready for installation; no finish coat required
Pultrusion: Strong, stiff composite material, in profile form, made from polymeric resin and glass fiber. Also used to refer to the process for producing these profiles
Push-out casement: A casement with no crank handle; window is opened by releasing sash lock and pushing the sash outward
Rail: Horizontal components of a window sash or door panel framework
Reinforced mull: Mull that uses a structural material (wood, aluminum, steel, LVL) to provide a stronger joint
Removable Interior grille: Interior grille that can be readily removed for cleaning
Reverse Cottage/Oriel window: Double-hung window where the upper sash is larger than the bottom sash
Rough opening: Opening in a wall for the installation of a window or door. The rough opening is larger than the actual unit to allow for shimming and insulating.
Sash: Rail, stile and glass components joined together the form the venting capability of a window
Sash glazed /Sash set: Fixed window with a separate sash and frame intended to replicate the look of nearby venting windows
Seal: A compressible surface that inhibits air and water passage
Segmented arch: Multiple arch windows mulled horizontally to provide a single continuous arch
Shim: A wedge often made of wood used to plumb and/or level a window or door in the rough opening
Sidelight: Tall, narrow unit placed alongside a window or door
Sill: Horizontal member that forms the bottom of a window or door frame
Sill Nose: Traditional exterior trim component that attaches underneath and extends out beyond the sill
Simulated divided light: Use of interior and exterior grille with no spacer between the glass panes; used to simulate the look of a window with multiple glass lites
Single-hung: Double-hung styled window in which the top sash is inoperable
SmartSun™ glass: Andersen brand of a glass option that reduces solar heating but allows high visible light transmission
Solar Heat Gain Coefficient (SHGC): A measurement of the sun's heat energy that passes through the window/door. The lower the value the less heat gain thru the product.
Sound Transmission Class (STC): Rating system used to measure how much sound is transferred through windows/doors (see also OITC)
Springline™ windows: Round top picture windows
Stile: The vertical components of a window sash or door panel
Stool: Flat, interior trim member located at the sill of a window or door, typically extending into the room and horizontally beyond the extension jambs
Stop: A trim member attached to the window or door intended to hold, position or separate components
Stormwatch® protection: An Andersen brand name for a series of upgrades you can specify to meet increased code performance in coastal areas. Check your local codes for performance requirements in your area
Sun glass: Tinted glass that reduces heat gain
Sustainable Forest Initiative (SFI): Forest certification standard dedicated to promoting sustainable forest management
Tempered glass: Safety glass that is stronger than annealed glass and breaks into small pieces
Threshold: Decorative wood component used as a transition door sill to the interior flooring
Top hung insect screen: Insect screen used on patio door and are secured from the top; results in smoother operation
Transition block: A decorative wood piece used to cover the joint between extension jambs or casings
Transom: Window positioned directly above another window/door
Triple pane: Glass construction consisting of three distinct layers of glass and two air-spaces
True Divided Light (TDL): Windows and doors in which multiple smaller glass lites are framed in a single sash or panel
TruScene® insect screens: Unique to Andersen this patented micro-fine stainless steel mesh provides 50% more clarity than typical Andersen insect screen cloth
U.S. Green Building Council (USGBC): Non-profit trade organization that promotes sustainability in how buildings are designed, built and operated
U-Factor: Commonly used measurement of heat transmission through a window/door. The lower the U-Factor, the better the insulating value.
Unobstructed glass opening: Visible glass area
UV protection: Percentage of Ultra-Violet (UV) transmission from the sun's energy. The lower the number, the potential for reduced fabric fading. (See Damage Function)
Vapor barrier: Watertight material used to prevent moisture migration around windows and doors
Vent Limiter: Device that restricts window operation and cannot be disengaged without tools or special effort.
Venting unit: Window or door that opens; operates
Vinyl: Polyvinyl chloride (PVC) material that is very durable and resistant to corrosion.
Visible light transmission: The fraction of the light allowed to enter through a window
Weatherstrip: Compressible material designed to seal the sash or panel to the frame
Weep holes: Small holes placed on the exterior of a window or door that allows for water drainage
Window Opening Control Device (WOCD): Device intended to restrict the opening dimension of a window when first activated to less than 4 inches, but can be disengaged to allow full opening of the sash for escape and rescue, but reengages when the sash is closed such that the sash will open to a less than 4 inch dimension when opened again.