A - Technical Dictionary

ALLOWABLE STRESS                            
The maximum unit stress permitted under working loads by codes and specifications.

A composition of two or more metals to obtain a desired property.

ALPINE AREA                                         
Areas generally subject to snow, or places where snow can add a significant load to buildings, or cause difficulties with egress.

A change to a building or facility that affects or could affect the usability of the building or facility or portion thereof.  Alterations include, but are not limited to, remodelling, renovation, rehabilitation, reconstruction, historic restoration, resurfacing of circulation paths or vehicular ways, changes or rearrangement of the structural parts or elements, and changes or rearrangement in the plan configuration of walls and full-height partitions.  Normal maintenance, re-roofing, painting or wallpapering, or changes to mechanical and electrical systems are not alterations unless they affect the usability of the building or facility.

ALTERNATING CURRENT                    
A polarity of current which is reversed periodically, creating a regular system of sine waves.  Commonly known as AC current.

AMBIENT TEMPERATURE                     
The temperature of the surroundings.

A unit describing the rate of flow of an electric current.

A level ground surrounded by rising slopes; a semicircular rising gallery in a theatre.

ANAEROBIC ACTION                             
Biological process in the absence of oxygen. 

Any device used to secure a building part or component to adjoining construction or to a supporting member.

ANCHOR BOLT                                        
A bolt to secure a wooden sill plate to concrete, or masonry floor or wall

A secure means of attachment to which the personal fall arrest system is connected

ANCHORED TRACK                               
A galvanized steel I-beams anchored to the building structure in parallel to enable a roof machine to traverse horizontally along the rooftop

Auxiliary; supplementary; subsidiary; subordinate; (of computer equipment) additional in any way, not a necessary part of the computing process; subserving; ministering.

To soften a metal piece and remove internal stresses by heating the piece to its critical temperature and allowing it to cool very slowly.

ANNEALED GLASS                                 
Glass that has not been heat-treated and is essentially strain free; often referred to as " float glass."

The effect heat has on the wire springs of a chair, sofa, or vehicle seat.  It causes the springs to flatten out and lose their tension.  Does not indicate a liquid accelerant was present.  May be the result of a rapid or smouldering fire.

ANODIC COATING                                  
The surface finish resulting from anodizing.  Coatings may be produced by clear, integral colour or electrolytically deposited colour processes.  Also see Anodize.

A process that provides a hard durable oxide film on the surface of aluminium.  This coating can produce colouring and finishing that both protects and beautifies the aluminium.

ANT CAPS                                                
Steel plates affixed to the ends of wooden posts that support a floor.  As termites cannot penetrate steel, they are forced into the open and can be detected.

Piece of equipment for occupants' use connected to an installation. 

A method of decoration in which a motif is cut from a piece of material and then attached to an object.

APPROVED ALTERNATIVE                  
Proprietary specifications that name one or more specific products but indicate the option of meeting the requirement of the specified items with similar products by stating or approved alternative after the specified product(s)

A drawing issued for actual construction use as opposed to one issued for approval, guidance, coordination, costing or for information only. 

Refers to manufacturers, materials, products, systems, or equipment approved by the A/E for use in place of those specified.

A trim board that is installed beneath a windowsill

APRON FLASHING                                  
A horizontal or angled flashing installed where a roof meets a vertical projection such as a chimney or parapet wall.  Use this term instead of BASE FLASHING.

Conduit for conveying water over long distances, and including the supporting structure.

A form of intricate decoration comprising stylized, intertwined leaves, other vegetation and scrolls. Of Arabian origin, it is used in friezes and borders of furniture.

Covered and sometimes arched passage, usually with shops on one or both sides. 

Curved structural member designed to carry loads between points of support.

ARCH BRIDGE                                         
Bridge that has one or more arches as its main structure.

ARCH WINDOW                                       
Half-circle picture window.

A designer of buildings, specifically someone professionally qualified as such; a designer of ships (naval architecture); a maker or planner (of something).

ARCHITECT OF RECORD                     
An architect (as prime consultant) for a specific project, in good standing with licensing requirements, at the time of the project.

Pertaining to architecture; constructive; controlling, directing; pertaining to the arrangement of knowledge (metaphysics).

Drawing which shows the appearance of general arrangements, assemblies, component ranges and details of a construction project.

The art or science of building; structure; specifically one of the fine arts, the art of designing buildings; style of building; structures or buildings collectively; the overall design of the software and especially the hardware of a computer, or of a local network; organization, framework, structure.  [Greek architekton master-builder, from prefix archi- chief, and tekton a builder]

A moulding used to disguise the gap between joinery and other work.

When pure electricity jumps across a gap in a circuit.  The intense heat at the arc may ignite any nearby combustible material or may fuse the metal conductors.

The area through which a swing door travels. 

Total area of all enclosed spaces forming entrance halls, corridors, staircases, lift wells, connecting links and the like. 
When applied to a building or storey, the floor area includes all the space capable of being used.  It includes any roofed area, canopy, veranda or covered walkway, etc. 
Floor area is used in a number of different contexts in the BCA.  It is therefore necessary to define each of these contexts:
- In relation to a building—the sum of the areas of all storeys. 
- In relation to a storey—the floor area of the storey includes any enclosing walls.  Where there is no enclosing wall in a part of a storey, those areas which may be used for storage, or other purposes, by occupants must be included as appropriate.  It therefore includes any roofed area, including a canopy, verandah or covered way if it contributes to the functioning of the building.  Internal walls, columns, shafts or the like are not deducted. 
- In relation to a room—the bounding walls determine the limits of the floor area.  Internal walls, columns or the like are not deducted.
- In relation to a fire compartment—the fire compartment may not be bounded by walls in all places.  If this is the case and a roofed area contributes to the fire load, it should be considered as part of the floor area. 
Total of all enclosed spaces fulfilling the functional requirements of the building measured to the internal structural face of the enclosing walls.  Includes areas occupied by partitions, columns, chimney breasts, internal structural or party walls, stairwells, lift wells, and the like.  Includes lift, plant, tank rooms and the like above the main roof slab.  Sloping surfaces such as staircases, galleries, tiered terraces and the like should be measured flat on plan.  Excludes any spaces fulfilling the functional requirements of the building which are not enclosed spaces (eg open ground floors, open covered ways and the like).  Excludes private balconies and private verandas. 
The actual occupied area not including the thickness of walls, partitions, columns, furred-in spaces, fixed cabinets, equipment, and unoccupied accessory areas such as corridors, stairways, toilet rooms, mechanical rooms and closets. 
(Residential buildings only) Total area of all enclosed spaces forming the dwelling measured within the structural internal face of the enclosing walls.  Includes areas occupied by partitions, columns, chimney breasts and the like.  Excludes balconies, public access spaces, communal laundries, drying rooms, lift, plant and tank rooms and the like. 
Total area of all enclosed spaces fulfilling the main functional requirements of the building (eg office space, shop space, public house drinking area, etc.) 

AREA OF REFUGE                                  
A floor area to which egress is made through a horizontal exit. 

An area where persons unable to use stairways can remain temporarily to await instructions or assistance during emergency evacuation. 

An inert, non-toxic gas used in insulating glass units to reduce heat transfer.

Italian term for a long cupboard with doors, used for storing linen.

Seating for one that has both a backrest and armrests.

French term for a linen press, wardrobe or large cupboard.

Sharp external angle formed by the meeting of two surfaces.

A collection of entities in which duplication is allowed and which is indexed by order. 

ART DECO                                              
A 1920s style characterized by setbacks, zigzag forms, and the use of chrome and plastic ornamentation. New York's Chrysler Building is an architectural example of the style.

ART DECO STYLE                                   
Decorative style named after the Exposition Internationale des Arts Decoratifs et Industriels Modernes ( Paris, 1925), which supplanted Art Nouveau. Streamlined, geometric forms, and bright bold colors characterize the style. Furniture made in this style often used exotic woods and other materials.

ART NOUVEAU STYLE                          
An exaggerated asymmetrical decorative style that originated and spread throughout Europe from circa 1890 to 1910. It makes use of undulating forms of all kinds, notably the whiplash curve of tendrils or plant stems, but in particular flames and waves and flowing hair of stylized female figures.

ARTS AND CRAFTS STYLE                   
A furniture style that emerged in England toward the end of the 19th century. Pioneered by William Morris it rejected the decorative excesses of the Victorian era, and glorified simple craftsmanship. Gustaf Stickley pioneered a similar movement in the United States in the early 20th century.

AS-BUILT DRAWING                               
Drawing used to record the details of a construction following its completion.  (Synonym to record drawing)

ASHCAN SCHOOL                                
 A group of New Jersey realist artists at the beginning of the twentieth century who rejected the formal subject matter of the academy and focused on gritty urban scenes and ordinary, even ugly, aspects of life.

An accurately cut and squared stone block

American Society of Heating, Refrigeration and Air Conditioning Engineers.

A bituminous waterproofing agent

(Collage) Forms of modern sculpture and painting utilizing ready-mades, found objects, and pasted fragments to form an abstract composition. Louise Nevelson's boxlike enclosures, each with its own composition of assembled objects, illustrate the style in sculpture. Pablo Picasso and Braque developed the technique of cutting and pasting natural or manufactured materials to a painted or unpainted surface. Picasso incorporated elements such as wallpaper pieces and chair caneing.

Combinations of components or materials for a particular function eg vanity unit cabinet, window, pump, etc. 

ASSEMBLY AREA                                  
(1) A building or facility, or portion thereof, used for the purpose of entertainment, educational or civic gatherings, or similar purposes.  For the purposes of these requirements, assembly areas include, but are not limited to, classrooms, lecture halls, courtrooms, public meeting rooms, public hearing rooms, legislative chambers, motion picture houses, auditoria, theatres, playhouses, dinner theatres, concert halls, centres for the performing arts, amphitheatres, arenas, stadiums, grandstands, or convention centres.
(2) A outdoor location designated for assembly of occupants in the event of an emergency building evacuation.

ASSEMBLY BUILDING                            
Describes buildings classifiable as Class 9b buildings.
ASSEMBLY DRAWING                           
Drawing representing the relative position and/or shape of a high-level group of assembled parts. 

ASSISTED RESCUE PATH                     
A portion of the accessible means of egress which begins at the area of rescue assistance and terminates at the public way. 

ASSOCIATE ARCHITECT                      
An Architect who has an arrangement with another Architect to collaborate in the performance of services for a project or series of projects. 

l A down pipe bracket (see also door hardware)
l A member or combination of members applied to one or both doors of a pair at their meeting edges (meeting stiles).  The astragal closes the clearance gap for the purpose of either providing a weather seal, minimising the passage of light between the doors, or retarding the passage of smoke or flame during a fire.  Also known as "Meeting Stile Seals", Astragal is a term used for the seal that seals the central join of two swinging doors.

ATRIUM AND ATRIUM WELL                 
A vertical void within a building connecting two or more storeys, typically closed off at its top by a roof comprising a concrete slab, roof sheeting, glazing, or the like.  An atrium can pose unique fire and smoke hazards. 

Two or more structures joined together by a common wall

ATTACHED PIER                                     
Integral part of a wall, in the form of thickened sections placed at intervals along the wall. 

Reduction in strength of sound measured in decibels (dBs).

A room within the roof of a building

Room mainly contained within a pitched roof. 

AUDIO/VIDEO STUDIO                           
The following is a collection of typical rooms and a description of their function:
One room specially designed and designated for digital audio recording, audio editing, audio special effects, mixing and mastering.  Number of occupants can vary from 1-4: audio operator, script checker, reading coach and production assistant
One room especially designed and designated to edit audio files recorded in the Audio Control Room.  Recorded material will be transferred via network or removable disk to this editing station.  Number of occupants can vary from 1-4.  Audio operator, script checker, reading coach and production assistant.
A room especially designed and designated for the recording of single voices and video narration.
[Physically identical to AUDIO CONTROL ROOM]
Room to be used for meetings, video presentations, general workspace, review of completed programs.
A room designated for the storage of field recording equipment and portable lighting/grip items.  Used by 2 person field recording crew.
Central entrance giving access to individual sections in the studio facility.  Because of the nature of the activities and also the ones invited for recording activities, a reception desk may be.  Toilet facilities are provided so that visitors don't use the facilities for the Audio/Video staff.
Shop space may be designated for the adjustment and repair of audio and video equipment if no other technical maintenance area is nearby.  This includes any repairs that require disassembly of any device or extensive adjustment and testing that would be impractical while still in service; and the set up and testing of new equipment prior to placing in service.  Staffed by one repair technician.
Room (1) designated for the storage of recording media.  Organization of various types of recording media, individual media retrieval as needed.  Cared for by librarian. 
One enclosed office and an open office area is needed for the day to day support of activities related to the audio/video work.  A conference presentation room will also be needed.
Toilet facilities with clothing change areas, as well as a room for doing actors' make-up.  Used by staff and visiting participants in recording sessions.  Toilet facilities to be sized for a maximum of 50 persons.
Three (3) identical preview rooms designed and designated for off-line audio/video functions.  One of the rooms could be for future expansion, but must be accommodated during design.  Could also be used as editing rooms or offices.
The number of occupants can vary from 1-2, including a graphics operator, production assistant, or program content representative(s).  These rooms may not always be occupied by A/V personnel but could be used by other personnel working temporarily with the A/V department.
Small room with counter and sink for warming or distributing refreshments during recording sessions. 
Note: Once that a recording session has begun the directors may not break for a meal as scheduled thus a means of keeping food 'safe' such as refrigeration and re-heating is needed.  This space may double as that function.
A room especially designed and designated for dubbing, maintaining quality assurance masters, digitizing video for off-line editing.  This room is the central connecting point for various types of signal cabling between all control rooms and studios.  The number of occupants can vary from 1-5, including a video operator, quality assurance technician, and system support technician.
Room (1) specially designed and designated for digitizing video footage, video editing, text processing, mastering digitized programs.  Number of occupants can vary from 1-4, including video operator, production assistant, program content representative(s).
Room (1) specially designed and designated for the recording of video scenes without accompanying audio.  Audio/video system set up, lighting and rigging set construction and prop arrangement in preparation for a recording session.  The lighting grid level needed is 4,250 mm.  Lighting is suspended from below the lighting grid. 
Located adjacent to Audio/Video Control Room.  A small corridor that functions as a sound lock connects the Control Room and the Audio/Video Studio.  An equipment storage closet for the Control Room is accessed from this corridor.  Provide an additional set of oversized, sound rated, double doors in addition to the sound lock for movement of props and other equipment.
Number of occupants:  1-20;  camera subjects, drama cast, video, lighting and support crews.

A strong, sealed vessel for carrying out chemical reactions under pressure and at high temperatures, or one in which super-heated steam under pressure is used for sterilizing or cooking.

The spontaneous ignition of gases or vapours given off by a heated material.  Synonymous with ignition temperature except that no external ignition source is needed, since the material has heated itself to its ignition temperature.

AUTOMATIC CLOSING                           
In relation to fire doors etc; designed to operate when activated by a heat, smoke or fire sensing device

AUTOMATIC FLUSH BOLT                     
Bolts are mechanisms that keep doors secure, and locked. Flush bolts are a particular type of bolt that is flush, or even, with the side of the door. A manual flush bolt requires someone to lock, and unlock it manually. An automatic flush bolt depends on the opening, and closing of a double door to operate properly. Manual flush bolts are common on French-style doors, while automatic flush bolts are common on doors used as fire exits. Doors that must remain unlocked, but closed, during business hours commonly utilize automatic flush bolts. Flush bolt installation requires two flush bolts laying even with the edge of the door. One of the bolts should be on the top of the door, and the other should be positioned on the bottom of the door. The bottom and top edges of the door must have holes for the bolt to extend through to pass into the space within the door jamb. The deadbolt is located in between the top, and bottom flush bolts. Automatic flush bolts can be installed on wood doors or aluminium doors. In a set of double doors with automatic flush bolts, one of the doors is active and one is inactive. The active door is the door with the handle or push lever that opens the door. This is also the door with the dead bolt or other locking device. The inactive door is the door with the automatic flush bolts. These types of doors are commonly seen in schools, and hospitals and act as one of the main exits out of the building. For this reason, many states have laws governing the use of automatic flush bolts on fire exits. When the double doors are closed, the automatic flush bolts only allow the active door to open. Once the active door opens, the flush bolts release and the inactive door unlocks and is free to open. Upon the active door closing, the automatic flush bolts will snap back into place making the active door the only side that can be opened.

AUTOMATIC OPERATOR                       
Power-operated, door-activated device and control, actuated by approaching traffic or remote switch.

AUTOMATIC RE-OPENING                    
A system where doors automatically reverse on the closing cycle when meeting resistance from a person or object. 

A road lined with trees

AWNING WINDOW                                  
A type of window with a top-hinged sash that swings out at the bottom.

A light or temporary roof with open sides

A straight line about which the parts of a figure, body or system are symmetrically or systematically arranged; a fixed line adopted for reference in co-ordinate.

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