basement
Enable an agent to recognise a basement, assess its below-grade conditions and suitability for intended uses, and identify evidence needed before access, occupation or alteration.
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 basement, assess its below-grade conditions and suitability for intended uses, and identify evidence needed before access, occupation or alteration.
A basement is a storey of a building whose floor lies wholly or partly below the surrounding ground level.
It can be Identify and map basement boundaries using building geometry and surrounding grade.; Inspect and document seepage, dampness and changes following rainfall or groundwater events.; Trace drainage, pumping and discharge dependencies to plan maintenance or investigation.; Assess evidence needed for a proposed storage, plant, recreation or occupied use.; Evaluate access and escape arrangements against the intended use and applicable requirements.; Screen excavation, wall penetrations and fit-out proposals for specialist review..
Distinguishing features
Compare floor and ceiling elevations with adjoining ground around the perimeter; a low floor within a building alone does not establish basement status.
Establish that the space forms a building level or substantial building volume; a crawl space or service void requires separate classification evidence.
An exposed wall or exterior door does not alone exclude a basement: record the full grade profile when assessing a walkout or daylight configuration.
Separate physical classification from labels such as cellar, lower ground floor or finished basement, whose meanings may depend on local usage and rules.
Distinguish the enclosed space from its foundations and retaining walls: those components support or bound the basement but are not the basement itself.
Scope
+ Position and extent relative to adjoining ground and other building levels
+ Basement enclosure, retaining interfaces, floor and usable internal volume
+ Groundwater, surface-water and drainage relationships affecting the space
+ Access, escape routes and environmental conditions relevant to intended use
+ Basement-specific constraints on occupation, storage and alteration
- Whole-building design, ownership and occupancy management
- Foundations as structural systems beyond their interfaces with the basement
- Standalone underground tunnels, bunkers, caves and buried infrastructure
- Detailed models of installed pumps, boilers, ventilation equipment and utilities
- Stored goods, furnishings and activities occupying the basement
Characteristics
- Relationship to adjoining grade
- Floor and ceiling elevations relative to surveyed ground at identified perimeter points, in m Establishes below-grade extent and supports classification without assuming uniform ground level.
- Basement configuration
- Fully below grade, partly below grade, walkout/daylight, split-level, other, unresolved; record classification basis Differentiates exposure, access and water-entry conditions.
- Usable geometry
- Floor area in m²; clear height and local obstructions in m Supports assessment of movement, equipment access and intended use.
- Relationship to building
- Containing building, level above, lower underground levels, shared walls and connected spaces Identifies the basement's extent and dependencies on adjacent construction.
- Water and dampness condition
- No observed ingress, dampness, active seepage, ponding, flooding, unknown; include location, date and weather context Separates current observations from evidence about recurring or seasonal exposure.
- Water-management dependencies
- Ground grading, perimeter drains, waterproofing, sump, discharge destination, backflow protection and power dependencies Shows which systems the basement relies on to remain usable.
- Indoor environmental measurements
- Temperature in °C, relative humidity in %, radon in Bq/m³ where measured; include method, location and duration Provides evidence for evaluating conditions in a ground-adjacent enclosed space.
- Access and escape configuration
- Stairs, doors, exterior exits, window wells and routes to a safe destination Supports use-specific access and escape assessment.
- Use and approval status
- Observed use, intended use, documented permitted use, approval authority and unresolved restrictions Prevents finishes or existing occupation from being treated as proof of suitability.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Below-grade identity Establishes which building volume is the basement and how it relates to surrounding terrain.
Basement identity depends on geometry and classification context, rather than the room's name or finishes.
Grade and level
Describes the vertical relationship between the building space and exterior ground.
Perimeter grade profile
Record floor, ceiling and adjoining-ground elevations around the perimeter, including slopes and exposed sides.
- How far above or below adjoining ground are the floor and ceiling at each relevant perimeter segment? measurement
- Which survey, drawing or inspection establishes these elevations and their reference datum? provenance
Space and classification
Separates the basement volume from neighbouring spaces and ambiguous labels.
Basement boundary
Identify the included level or volume and document the basis for distinguishing it from crawl spaces, cellars and above-grade lower floors.
- Which connected rooms, partial levels and service voids belong to this basement? boundary
- What physical or jurisdictional definition supports calling this space a basement? definition
Ground-retaining enclosure Records the basement's enclosure, structural interfaces and constraints on changing its geometry.
Basement walls and floors can interact with retained ground and building supports, making ordinary-looking alterations consequential.
Walls, floor and supports
Identifies construction roles at the boundary between enclosed space, soil and the building above.
Enclosure structural roles
Distinguish retaining, load-bearing and partition functions, recording evidence and visible distress without assigning an unverified cause.
- Which basement walls and supports retain ground or carry loads from the building above? boundary
- What drawings or assessments establish these roles, and what cracking, movement or deterioration has been observed? provenance
Clearance and alteration
Connects available space to constraints on excavation, openings and removal of construction.
Alteration-sensitive geometry
Record headroom restrictions and the ground, foundation and utility interfaces affected by proposed changes.
- What clear heights remain below beams, ducts, stairs and other local obstructions? measurement
- What evidence and specialist assessment are needed before lowering the floor, removing a wall or forming an opening? action
Water entry and control Traces water exposure, entry paths and the systems controlling water around and within the basement.
A basement's usable condition can depend on exterior water levels, drainage continuity and active pumping.
Exposure and entry paths
Distinguishes observed water from possible entry mechanisms and event conditions.
Water event evidence
Locate water and dampness observations at walls, joints, floors, penetrations, openings and drains, with their timing.
- Where and when has water appeared, and what rainfall, groundwater or drainage conditions accompanied it? provenance
- What investigation would distinguish ground seepage, surface entry, plumbing leakage, sewer backup and condensation? action
Drainage and resilience
Records water-control routes and the conditions under which they may cease to function.
Water-control chain
Trace barriers, drains, sumps and discharge routes, including maintenance access and dependencies.
- Where does intercepted or pumped water discharge, and which parts of that route are verified? boundary
- What inspection, maintenance or contingency action is required if drains block, discharge is restricted or pump power fails? action
Basement indoor environment Addresses moisture, air exchange and potential contaminant pathways in the enclosed below-grade space.
Ground contact and connections to the rest of the building shape conditions that appearance alone cannot establish.
Moisture and surfaces
Connects indoor humidity, surface conditions and concealed construction to observed dampness.
Moisture condition evidence
Record time-dependent environmental measurements and observations behind or around basement finishes where accessible.
- How do temperature, relative humidity and surface moisture vary by location and season? measurement
- Which linings, floor coverings or inaccessible cavities limit confidence in the observed moisture condition? boundary
Air pathways and testing
Identifies air exchange with outdoors, soil, adjacent spaces and installed equipment.
Air-quality evidence
Record ventilation arrangements and applicable testing for soil gas or equipment-related contaminants without assuming a hazard is present.
- Which openings, ducts, penetrations and equipment connect basement air to soil, outdoors or occupied rooms above? boundary
- What measurements or inspections are needed to assess air quality for the intended use, and under what operating conditions? action
Access, use and conversion Relates basement access and documented conditions to existing or proposed activities.
A basement may be accessible and finished while still requiring further evidence before a particular use or conversion.
Entry and escape
Records movement into, through and out of the basement, including routes involving exterior ground features.
Route usability
Map stairs, doors, openings and window wells with dimensions, obstructions and discharge destinations.
- What are the dimensions and operating conditions of each access or potential escape route, including exterior wells and steps? measurement
- Which routes require assessment or modification for the proposed occupants and use? action
Use evidence and permissions
Separates observed activity, physical suitability and documented authorisation.
Proposed-use readiness
Record existing and intended uses alongside supporting approvals and unresolved basement-specific conditions.
- What records establish the permitted use, and do they cover the current basement layout and proposed activity? provenance
- Which unresolved water, air, headroom, access or escape conditions must be assessed before the proposed use begins? 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 describes the architectural sense, excluding geological basement rock.
- Code definitions, permitted occupancy and escape requirements require jurisdiction-specific verification.
- The single-storey residential example is indicative, not a dimensional or regulatory limit; larger buildings may have multiple basement levels.
- Which of these check these first hold for the sense of basement this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Fully below-ground basement
- Partially below-ground basement
- Walkout basement
- Finished basement
- Unfinished basement
- Which of these kinds and varieties hold for the sense of basement this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- International Code Council (ICC): International Building Code and International Residential Code include provisions applicable to basements; legal applicability depends on local adoption.
- Which of these standards and regulation hold for the sense of basement this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Storage and utility space
- Housing building services and mechanical equipment
- Habitable rooms where permitted and suitably constructed
- Below-ground vehicle parking
- Commercial or institutional accommodation
- Which of these real-world use hold for the sense of basement this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Number of basement storeys in a typical house with a basement - 1 - storey
- Which of these typical measurements hold for the sense of basement 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.
- Groundwater ingress, surface-water flooding or sewer backup
- Persistent dampness, condensation and mould growth
- Accumulation of soil gases, including radon
- Cracking or deformation of retaining walls under soil and water pressure
- Restricted escape and rescue access during fire or flooding
- Which of these failure modes and hazards hold for the sense of basement this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Building codes differ in how surrounding grade determines whether a level counts as a basement or a storey above ground.
- Basement prevalence and construction methods vary with groundwater conditions, geology, climate and local building practice.
- The terms basement, cellar and lower-ground floor overlap differently across regions.
- Which of these regional variation hold for the sense of basement 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.
- cellar - Usually denotes below-ground space associated with storage; basement describes a building level more generally, although local usage overlaps.
- crawl space - A low underfloor space generally intended for access to services rather than use as a full-height storey.
- foundation - The foundation transfers building loads to the ground; a basement is a building level whose walls and floor may form part of the foundation system.
- bunker - A bunker is defined by its protective purpose and construction, whereas a basement is defined by its position relative to ground level.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of basement this model covers, and on what evidence? provenance
What the second pass must settle
- Which registry or world-model entries already cover basement, cellar, crawl space or underground storey, and where should their boundaries or links lie?
- Which jurisdictional definitions distinguish a basement from a storey above grade, particularly on sloping sites and in walkout configurations?
- Which authoritative requirements apply to the intended occupancy, including headroom, access, escape, ventilation and fire separation?
- What site-specific evidence establishes seasonal groundwater exposure, flood history, soil-gas conditions and drainage performance?
- What inspection depth and monitoring duration are sufficient to assess a finished basement when enclosure surfaces and water-control systems are concealed?