NCIDQ IDIX key terms

The research phase before design begins, in which the designer gathers client goals, budget, schedule, existing conditions, and user needs, then documents them as written requirements that the design must satisfy.

A concise written summary of the client's needs, constraints, and priorities produced at the end of programming; it becomes the benchmark against which later design decisions and post-occupancy performance are judged.

A document recording the assumptions, criteria, and standards that govern the project, such as occupancy counts, code edition, load assumptions, and performance targets, so every consultant works from the same baseline.

A grid that rates how closely each pair of spaces should be located, using symbols or numbers for required, preferred, neutral, and undesirable relationships; planners translate it into a bubble diagram and then a block plan.

A loose, non-scaled diagram of circles or blobs connected by lines that shows desired proximities and circulation between functional areas before dimensions or walls are fixed.

A scaled diagram that converts the bubble diagram into rectangles of approximately correct size and proportion, testing whether the required areas and adjacencies actually fit within the building envelope.

The floor area of spaces directly usable for program functions, excluding circulation, walls, mechanical rooms, and other support space; comparing it with gross area reveals the building's efficiency ratio.

The total floor area enclosed by the exterior faces of the building's enclosing walls, including all interior walls, shafts, corridors, and service space; used for code occupancy calculations and cost per square foot.

The floor area used to compute a tenant's lease obligation, typically measured to the centerline of shared partitions or the exterior glass line, and always defined by the specific leasing standard cited in the contract.

The paths people use to move through a space. Primary circulation is the main route linking entrances and major destinations; secondary circulation branches off it to reach individual work areas or rooms.

Designing environments so they can be used by the widest possible range of people without adaptation, addressing reach ranges, clear floor space, operable force, and sensory cues beyond the minimums required by accessibility codes.

A continuous, unobstructed path connecting accessible elements and spaces, meeting minimum clear width, slope, surface, and turning-space criteria so a person using a wheelchair can travel independently.

The unobstructed area required for a single wheelchair or mobility device to approach and use a fixture, control, or element, commonly a 30 by 48 inch rectangle positioned per the applicable accessibility standard.

The calculated number of people a space or building is designed to hold, derived by dividing floor area by the code's occupant load factor for that use; it drives egress width, exit count, and plumbing fixture counts.

The continuous and unobstructed route from any point in a building to a public way, comprising the exit access, the exit, and the exit discharge, with each segment subject to its own code limits.

The measured length of the egress path from the most remote point in a space to the nearest exit, limited by code according to occupancy type and whether the building is sprinklered.

A corridor segment with only one direction of escape, permitted only up to a code-limited length because occupants could be trapped if fire blocks the single outlet; sprinklers often allow a longer limit.

The period, in hours, that a building assembly withstands a standardized fire test; ratings are assigned to walls, floors, and shafts based on construction type and separation requirements between uses or occupancies.

A fire partition separates spaces within a floor, such as corridors from rooms, and is typically rated one hour; a fire barrier carries a higher rating and must be structurally independent, often separating different occupancies or areas.

The code category assigned to a building or portion of it based on how it is used, such as business, mercantile, assembly, or residential; the classification sets allowable height, area, egress, and fire protection requirements.

The space between a suspended ceiling and the structure above when used for return air; codes restrict combustible materials and require that wiring and insulation in a plenum meet stricter flame and smoke limits.

Dividing a building into separately controlled thermal zones so that spaces with different loads, sun exposures, or occupancy schedules can be conditioned independently, improving comfort and energy use.

The documented process of verifying that building systems are installed, function, and perform according to the owner's requirements, beginning in design, continuing through construction, and often revisited in retro-commissioning.

A drawing viewed as if looking down at a mirror held above the ceiling, showing ceiling heights, light fixtures, diffusers, sprinkler heads, and other overhead items coordinated in plan position.

The coordinated drawings, schedules, and specifications that fully describe the work and become part of the contract; drawings show quantity and location while specifications govern quality and installation methods.

The numbered sections of a project manual organized by construction work type, such as concrete, finishes, and conveying systems, following a standard masterformat-style structure so bidders can price and compare scope consistently.

A specification that states required results, such as fire rating, acoustical value, or durability, and leaves the means of achieving them to the contractor, in contrast to a prescriptive specification naming exact products and methods.

A full-size sample of an assembly or finish installed on site or in a factory for approval before general work proceeds, letting the team judge appearance, workmanship, and performance against the specification.

A tabular list of every furniture, fixture, and equipment item with identifying number, description, finish, quantity, source, unit cost, and lead time; it links design intent to purchasing and installation.

A scaled drawing showing each furniture item in plan position, with clearances for use and circulation, power and data locations, and dimensions from walls so installers can place items without guesswork.

The interval between placing an order and receiving the item, critical to the project schedule because long-lead furniture or custom millwork can delay occupancy if not identified and ordered early.

The purchasing process for furniture, fixtures, and equipment, covering bid solicitation, vendor selection, purchase orders, tracking, receiving, and installation, managed against budget and schedule.

The ratio of light output to power consumed, expressed in lumens per watt; higher values mean more light for the same energy, and it is a key comparison when selecting lamp and fixture types.

A measure in kelvin describing whether a light source appears warm, neutral, or cool, such as 2700 K for residential warmth and 4000 K for neutral office light; it affects mood and perceived space.

A scale from 0 to 100 describing how faithfully a light source shows colors compared with a reference source; low values make finishes and skin tones look dull or distorted, so high values matter in retail and hospitality.

The installed lighting wattage divided by floor area, used by energy codes to cap how much power a space may devote to lighting; designers meet the cap through efficient fixtures and controls.

A single-number rating of how well a partition blocks airborne sound; higher numbers mean more privacy, and the rating is often paired with a field-tested value that accounts for real construction gaps.

A rating of how well a floor-ceiling assembly resists structure-borne impact noise such as footsteps; relevant in multistory residential and hospitality projects where footfall transfer is a common complaint.

A single number averaging how much sound a surface absorbs across speech frequencies; near zero means highly reflective, near one means highly absorptive, guiding ceiling and wall treatment choices.

The time sound takes to decay by 60 decibels after a source stops; long times make speech muddy in large rooms, while very short times feel dead, so target values depend on room use.

The steady ambient sound in a space from mechanical systems, outside traffic, and equipment; controlled background noise can mask distracting speech, while excessive levels harm comfort and concentration.

A written list of incomplete or defective work identified during substantial completion walkthroughs; the contractor must correct listed items before final payment and closeout.

The stage when the work is sufficiently complete for the owner to occupy and use it for its intended purpose, triggering warranty start, retention release, and the punch list process.

A written, signed amendment to the contract that modifies scope, price, or schedule after execution; it requires owner approval and typically adjusts the contract sum and time.

A formal written question from the contractor asking the design team to clarify or resolve ambiguous documents; responses become part of the record and may lead to a change order.