opening
a vacant or unobstructed space that is man-made
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise a man-made opening, assess its usable clearance and boundary conditions, and determine what passage or other use its present state supports.
An opening is a deliberately formed vacant space in or between constructed or manufactured elements that provides a passage, access, view, or route for material or energy transfer.
It can be Locate and distinguish the opening from its host and fitted components.; Measure the available profile and identify restrictions along its depth.; Compare a proposed person, object or component envelope with the observed clearance.; Identify the space reached and the intended function before proposing use.; Record obstructions, edge defects and protective-device states for inspection or maintenance.; Determine whether further measurements or an authorised assessment are needed before passage, uncovering or modification..
Distinguishing features
It denotes vacant space rather than the frame, cover or other material surrounding that space.
Its formation or deliberate retention is attributable to human activity; a similar natural void belongs outside this entry.
Its extent can be located relative to surrounding surfaces or a host object, rather than referring to unrestricted ambient space.
A doorway opening remains distinguishable from its door assembly: the assembly occupies or controls the void.
Whether a blind recess, accidental breach or temporarily covered aperture qualifies must be resolved explicitly rather than assumed from the word opening.
Scope
+ Openings deliberately formed or left vacant during manufacture or construction
+ The void's mouth, edges, depth and spatial extent
+ Relationships to the host object and spaces reached through the opening
+ Clearance, obstructions and changes in usable space
+ Intended passage, access, transmission or accommodation functions
+ Conditions at the opening that constrain safe use
- Naturally occurring cavities, gaps and geological openings
- Doors, windows, hatches, grilles and other components fitted to an opening
- The complete wall, vessel, machine or structure containing the opening
- Complete corridors, ducts, pipes and other extended routes
- The cutting, drilling or construction activity that creates an opening
- Figurative openings such as opportunities, vacancies and beginnings
Characteristics
- Formation basis
- cut; drilled; punched; cast or moulded; assembled around a void; other; unknown Supports the man-made classification and identifies how the opening relates to its host.
- Host and location
- host object or structure; bounding surfaces; local position and orientation Locates the void and separates it from neighbouring openings.
- Spatial form
- through-aperture; open-sided gap; blind recess candidate; other; unresolved Distinguishes a connection through material from other vacant-space configurations.
- Mouth profile
- circular; rectangular; slot-shaped; irregular; other; profile description Determines which shapes can enter and how clearance should be measured.
- Clear dimensions
- mm or m; width, height, diameter or profile-specific dimensions at stated locations Establishes actual available space rather than relying on a nominal size.
- Depth through host
- mm or m along a stated axis A thick or tapered opening can constrain passage even when its mouth is sufficiently large.
- Connected spaces
- identified spaces on each side; interior reached; unknown destination; not applicable Shows what passage through the opening would reach.
- Intended function
- human passage; object transfer; inspection or servicing; ventilation; drainage; light transmission; component accommodation; other; unknown Distinguishes intended use from uses that geometry alone makes possible.
- Current obstruction
- clear; partly obstructed; fully blocked; unknown, with observation time Determines whether the intended use is currently available.
- Closure and protection
- linked cover, door, guard, screen or barrier, with its observed state; none; unknown Connects use restrictions to the separate components that control access or exposure.
- Edge and surround condition
- observations of sharp edges, deformation, cracking, loose material or other local defects; unassessed Records conditions that may affect clearance, contact safety or the need for specialist assessment.
Analytical facets
- substance
- material
- origin
- manufactured
- agency
- inert
- mobility
- portable
- scale
- handheld
- affordances
- graspable
Also called
+55
Where this came from
oewn:2024 · CC BY 4.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 15 findings · 23 questions.
Void identity and boundaries Establishes which man-made vacant space is being modelled and where it ends.
An opening can otherwise be confused with its frame, a natural cavity or a larger route.
Human formation
Records the basis for treating the void as man-made.
Formation evidence
The proposed record should distinguish observed formation features from documented origin and inference.
- What observation or record supports that this vacant space was made or deliberately left by human activity? provenance
- Was it formed as an intended opening, or is it a breach whose inclusion requires a scope decision? boundary
Host-relative extent
Separates the void from surrounding material, fittings and adjoining spaces.
Opening limits
The opening needs explicit spatial limits without treating its surrounding material as part of the void.
- Which surfaces, edges or reference planes delimit this opening? boundary
- Where does this opening end and an adjoining cavity, duct or passage begin? boundary
Profile and clearance Captures the shape and available space relevant to fitting or passing through the opening.
A nominal width or mouth diameter alone may conceal a restriction within the opening.
Mouth geometry
Describes each relevant entrance profile in a stated orientation.
Measured mouth profile
The proposed measurements should identify the actual clear boundary and their reference frame.
- What is the clear profile at each mouth, including dimensions and units? measurement
- Do these dimensions describe the unfinished host aperture or the usable opening after fittings are installed? boundary
Depth and restrictions
Examines changes in clearance between the opening's mouths or along its usable depth.
Limiting clearance
Passage assessment should account for depth, taper, projections and the proposed item's orientation.
- How deep is the opening, and where is its most restrictive clear profile? measurement
- What movement path and orientation would the proposed person or object require to pass through? action
Connection and purpose Relates the opening to the spaces it reaches and the functions it is intended to support.
Geometric accessibility does not establish destination, intended use or suitability.
Spaces reached
Identifies the spatial connection made by the opening.
Destination and continuity
The record should distinguish a verified through-connection from an apparent opening with an unknown destination.
- Which spaces or interiors does the opening connect or expose? boundary
- What inspection or record verifies continuity through the opening? provenance
Intended transfer
Describes what the opening is meant to admit, release, expose or accommodate.
Function and use fit
The model should separate documented purpose from an agent's proposed use.
- What is intended to pass through or occupy this opening, and what establishes that purpose? definition
- What additional evidence is needed to judge the proposed use beyond geometric fit? action
Availability and exposure Records whether the opening is usable now and what local conditions constrain interaction.
An opening's usefulness and exposure can change when it is blocked, uncovered, damaged or guarded.
Obstruction and closure
Tracks material or components that reduce or prevent use of the void.
Present usable state
Current availability should be recorded separately from the opening's underlying geometry.
- What currently occupies, covers or blocks the opening, and how much clear space remains? measurement
- What authorised action, if any, would restore the intended clearance? action
Edge and destination exposure
Connects local edge conditions and the space beyond the opening to use decisions.
Interaction constraints
Assessment should consider both contact with the opening and exposure created by passage or uncovering.
- What observed edge defects, drops or conditions beyond the opening constrain approach or passage? boundary
- Which protective measures or further assessments are required for the proposed interaction? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This covers physical man-made openings, excluding opportunities, vacancies, ceremonies, and naturally occurring gaps.
- Terminology overlaps: hole, aperture, slot, and opening are distinguished differently across construction and manufacturing.
- Applicable dimensional requirements and protective measures depend on function, host structure, and jurisdiction; no universal size or governing standard is asserted.
- Which of these check these first hold for the sense of opening this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Doorway
- Window opening
- Ventilation opening
- Service penetration
- Access opening
- Slot
- Which of these kinds and varieties hold for the sense of opening this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- Industry Foundation Classes (IFC) - IfcOpeningElement - An entity for representing an opening or void in a building element; it does not cover every manufactured opening.
- Which of these identifiers and schemes hold for the sense of opening this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Allowing people, vehicles, or goods to pass through barriers
- Admitting light or providing a view
- Providing airflow or fluid passage
- Routing pipes, cables, and ducts through construction
- Providing access for inspection, operation, or maintenance
- Which of these real-world use hold for the sense of opening this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Clear width and height - Application-dependent; no meaningful range applies to the whole category - mm or m
- Clear cross-sectional area - Application-dependent - mm² or m²
- Depth through the surrounding element - Determined by the host element and opening geometry - mm or m
- Which of these typical measurements hold for the sense of opening this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Obstruction reducing passage, access, airflow, or drainage
- Falls through unguarded floor or roof openings
- Stress concentration or loss of structural capacity around an inadequately designed opening
- Uncontrolled passage of water, smoke, fire, air, or pests
- Cuts, impact injuries, or entrapment at exposed edges or constrictions
- Which of these failure modes and hazards hold for the sense of opening this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Hole - A hole may arise naturally or accidentally; the specified opening sense requires a man-made space.
- Door - A door is a movable closure; the doorway is the space it closes.
- Window - A window commonly denotes the installed frame and glazing assembly; a window opening is the space provided for that assembly.
- Recess - A recess is a depression that does not pass through the host element; an opening may provide a through-passage.
- Clearance - Clearance is the available separation between objects or boundaries; an opening is an identifiable spatial feature.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of opening this model covers, and on what evidence? provenance
What the second pass must settle
- Does the registry include blind recesses and open-sided gaps, or require a through-connection?
- Does man-made include accidental breaches and damage-created voids, or only intentionally formed or retained spaces?
- Does a fully closed or filled aperture retain its identity as an opening under the definition's vacant or unobstructed requirement?
- What boundary convention separates an opening through a thick host from a tunnel, duct or other extended passage?
- Which application-specific measurement conventions and use requirements should be linked for building openings, machine apertures and other host types?