Adaptive Reuse
Using a building for a different purpose than it was originally designed for. This probably would include changes to the building systems and perhaps a facade upgrade.
Air Infiltration
Unintended leakage of air through a building envelope, usually due to cracks in walls, windows, or doors.
A metal that is composed of more than one metallic element. Aluminum extrusion alloys
contain small amounts (usually less than five percent) of elements such as copper, manganese,
silicon, magnesium, or zinc. They enhance the natural properties of aluminum and influence the extrusion process.
A bolt or fastener that attaches a mullion to the building’s structure, and prevents movement against the action of dead or wind load.
Back Pan
A thin sheet of aluminum to create a weather barrier between the curtainwall and structure.
Backer Rod
A polyethylene or polyurethane foam material installed under compression and used to control sealant joint depth, provide a surface for sealant tooling, serve as a bond breaker to prevent three-sided adhesion, and provide an hour-glass contour of the finished bead.
A louvered or perforated sun-screen incorporated into the facade to reduce glare.
Butt Glazing
Glass lites structurally supported on only two edges (typically the head and sill) and silicone sealant weather seals between the unsupported edges.
Captured Glass
Glass edge fully enclosed on all three sides by a mullion.
Cassette System
A pre-assembled, modular facade system intended to facilitate on-site installation. Glass infill panels are pre-installed into an aluminum frame separate from the unit frame.
An artificial, stonelike material made by mixing cement and various aggregates such as sand, pebbles, gravel, or shale, with water and allowing the mixture to harden. It can be integrally clad with materials such as ceramic tile, brick, or stone, or panelized rain screen systems.
The preventive care of a building with the intention of extending its service life without altering its fundamental character or appearance. It is usually practiced with buildings of cultural or social significance.
A non-loadbearing facade system that is typically attached to the building structure at the floors or edge beams. Systems typically span floor-to-floor, but can also be designed to span multiple floors. Although not load bearing, systems must be engineered to resist live loads and to accommodate movements and deflections resulting from wind and seismic loads and from dead load deflection of the building structure. Traditional system designs include unitized, strip window, and stick built.
Differential Movement
Independent movement of curtainwall units and structural framing members relative to one another.
Double-Skin Facade
A facade with two layers that create a controllable cavity for active or passive environmental control. The cavity may range in depth from six inches to six feet.
An elastic material's ability to return to its original shape and position after the removal of load and excessive volumetric distortion.
The exterior building surface, including all foundation, façade, and roof elements. The envelope is also referred to as the building skin.
Rods, tubes or sections of specified shapes formed by pushing hot or cold metal and plastics through a shaped die.
Any surface of the building envelope exposed to the outdoor environment that is not a roof surface.
Facade Retrofit
Refers to any modification of the building facade through alteration or addition of components. This might be done for enhancing the appearance of the building, improving energy performance, or to correct failure on materials or components
Pre-formed strips of rubber or rubber-like components used to fill and seal a joint or opening.
Process of installing an infill material (typically glass, aluminum or stone panel) into a prefabricated opening.
Glazing Bead
A sealant or compound after application in a joint, however applied, such as caulking bead, glazing bead, etc. Also a molding or stop used to hold glass or other cladding panels in position.
Glazing Pocket
Three-sided opening on either side of a glass lite to allow for horizontal movement.
Highly Glazed
A facade system with a window-to-wall ratio greater than 50%.
Insulated Glass
Two or more lites of glass spaced apart and hermetically sealed to form a single-glazed unit with an annular space between each lite.
Intelligent Facade
Incorporates active or dynamic features to adapt automatically and intelligently for efficient environmental control.
Any material used to bond two lites of glass and/or plastic together to form a laminate.
Laminated Glass
Two or more lites of glass permanently bonded together with one or more interlayers.
Loadbearing Facade
An exterior enclosure system that is also the primary or secondary building structural system.
A horizontal or vertical member that structurally supports the cladding infill of a curtainwall against dead (in plane) or wind loads (out of plane).
Over Clad
The addition of another layer to an existing facade including sun screens and rain screens. A double skin facade can also be created through over-cladding.
Precast Concrete
A construction product produced by casting concrete in a mold, which is then cured in a controlled environment, transported to the construction site, and lifted into place.
The upkeep of a façade as closely as possible to its original condition through proper maintenance, repair, or any other physical treatment. Preservation or protection are frequently used in historic preservation field to refer to prevention of further change or deterioration.
Punched Window
An opening in a wall, typically square or rectangular, accepting a window unit.
The movement or distortion of a sash or frame causing a change in angularity.
The complete removal of an existing facade system and replacement with a new system. The re-cladding operation starts by stripping the building to its structural frame before installation of a new facade system.

Re-cladding can also refer to the removal and replacement of existing facade infill panels or the addition of new panel materials without removing or significantly altering an existing curtain wall framing system.
An action intended to recreate a part or whole non-existing facade. In historic preservation, the intent is to re-create the exact form and details of an original facade at it existed at a particular time.
To recondition a facade to an earlier state of performance or appearance, typically through repair and replacement of system components.
To renovate a facade that has deteriorated, with an emphasis on its appearance.
A retrofit action intended to return to sound condition an already deteriorated facade. In historic buildings, it to alter or modify the building for meeting new uses while maintaining the building's historic character.
To correct a damaged, faulty, or deficient facade. The intent is to repair the building while maintaining its architectural value.
A retrofit action primarily oriented to enhance the appearance of the building or style of the facade that does not necessarily consider historical accuracy.
The refitting of a facade by making changes to the building with the intention of improving their physical condition and returning it to a sound condition.
The maintenance or upgrade of original façade components to proper functioning.
Refitting or retrofitting the facade with an emphasis on maintaining the original appearance. Restorations may involve upgrades such as the use of a glazing material with improved thermal or acoustic properties.
To apply a new design, materials, or technology as a means to improve performance and appearance.
Selective Enhancement
The upgrading or addition of components into the existing façade system. This type of partial retrofit could include repairs such as re-caulking or gaskets replacement or the incorporation lightshelves, overhangs, and fins for improved day lighting and thermal performance.
Selective Replacement
Replacement of specific facade components such as windows, spandrel panels, vision, insulated panels, etc. that were part of the existing facade system.
Sight Line
The width of a sealant contacting glazing infill.
Silicone Glazed
Edges of glass structurally sealed to the mullions with structural silicone. The term "four sided structurally glazed" refers to glass panels sealed on all edges with silicone.
Spandrel Glass
Opaque glass located between vision glass to conceal structural columns, floor slabs, shear walls, and various mechanical components of a building.
Stack Joint
The connection of one curtainwall unit to another located directly above or below. This connection allows for the vertical expansion of both members.
Starter Sill
A flat member used to support the intial curtainwall units set in place on the first level.
Steel Wall
steel elements (beam, post, post-and-beam) supporting a wall with external cladding of brickwork, stone panels, insulated veneer, large boards, metallic panels, terracotta tiles, etc.
Stick System
Curtainwall system fabricated at a manufacturing facility, but assembled and completely installed on site. System designs typically consist of thin horizontals, thin spandrels, and thin glass.
Storefront System
A non-load bearing façade enclosure system typically used in commercial building entrances. Storefront systems are generally restricted to one and two stories in height due to the system’s wind-load resistance limitations.
Strip Window
A series of identical windows stretching across the face of a building.
Structural Glass Facade
A facade system utilizing exposed structural systems and highly glazed facades to maximize transparency, where glazing is bonded and/or anchored to supporting structure without the use of continuously gasket'ed aluminum pressure plates or caps.
Sun Screen
An additional layer over a facade with the main objective of sun-control such as perforated-panels or louver system, with the intention of reducing glare or the amount of daylight reaching the interior (such as brise-soleil).
Tempered Glass
Glazing that has been rapidly cooled from near the softening point or annealing temperature, under rigorous control conditions, to increase it mechanical and thermal endurance. Fully tempered glass is designed to "dice" into a multitude of small particles upon fracture.
Thermal Insulation
The reduction of heat transfer (the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence.
Unitized System
Refers to modular, prefabricated assemblies manufactured under factory-controlled conditions. Frames of aluminum extrusions are first assembled, insulated infill panels are installed, and finally, glazing operations are completed using gaskets and/or wet silicone. Unit systems lend themselves to structural glazing, as this procedure cannot be carried out on site.
Vision Glass
Transparant glazing used in a curtainwall unit.
Weep Hole
Drain holes or slots in a framing member to prevent the accumulation of condensation and water.
Wet Seal
The application of an elastomeric sealant between two objects to form a weather-tight seal.