BIM Use Cases (CUBs)

Modeling the ground strata (lithology) based on one or more geotechnical or hydrogeological boreholes. The most common purposes are to assess the stability and bearing capacity of the ground for foundation sizing (linked to Structural Analysis & Design — CUB7, CUB26.5), as well as to establish the presence and depth of the water table.

Modeling the terrain-surface topography based on a topographic survey, providing the support needed for subsequent site grading and for compliance with project requirements. The model shall include the delimitation of the studied plot(s) through geometric separation based on their cadastral boundary. The topographic model may be produced from a classic topographic survey or from digital reality-capture methods (ground LIDAR scanning, photogrammetry, aerial UAV/drone scanning).

Modeling public utilities in the immediate vicinity of the studied plot. These may include water manholes; sewerage; natural-gas connections/manholes; electrical connection points; equipment such as transformer stations; street fire hydrants, including pipes with diameters above DN 50.

Modeling existing buildings on the site (3D survey), enclosures (if any), as well as buildings, infrastructure and public amenities in the immediate vicinity of the studied plot, as applicable, depending on the purpose (sunlight study, CZMI approval, PUD, PUZ, etc.). The model may be produced from a classic topographic survey, a measured survey, or digital reality-capture methods (LIDAR scanning, photogrammetry, etc.).

A process in which stakeholders view one or more 3D models and provide feedback to validate various aspects of the design. These aspects include assessing compliance with project requirements, previewing the aesthetic appearance and placement of the building in a virtual environment, and establishing criteria such as siting, sightlines, natural lighting, security, accessibility, textures, colors, etc. This BIM use case can be carried out with a CDE, real-time rendering software, or dedicated VR/AR equipment. Virtual mock-ups can be produced at various levels of detail depending on project needs. One example is creating a highly detailed model of a small portion of the building, such as a façade or an infrastructure work of art, to quickly analyze design alternatives and resolve design and constructability issues.

Using existing-conditions information to identify potential sites for the investment, considering the assessment of solar orientation, sunlight and wind, the public visibility of the plot/objective, and the analysis of sightlines toward points of interest (natural or man-made). Other studies may include noise-level analysis, existing pollution and other data sources. Ideally, this CUB should also be connected to geographic information systems (GIS).

Capturing and defining project requirements: areas, functions, deliverable requirements, regulatory requirements, organizational requirements and an initial cost estimate. This phase defines the concept note and the design brief, from which simple massing, areas, hypothetical alignments, etc. may (but need not) result. Crucial decisions are taken at this design stage, bringing the greatest value to the project when the client is involved in evaluating options and the best approach is analyzed.

Producing the information models per discipline. Authoring the project's information models is an essential step for integrating this information into an intelligent database from which properties, quantities and costs can be extracted, charts generated, etc. Models may be federated or integrated (a single model may contain several disciplines), depending on project requirements. The required level of information (LOIN) for each model element is defined based on each project's requirements within the BIM Execution Plan (BEP), noting that the geometric and alphanumeric information should be at least sufficient to achieve the BIM use case for which the models are developed.

Structural analysis and design involves using the information models to substantiate the building's structural solution — analytical modeling of the structure (transferring geometry and properties from the physical BIM model to the calculation model), defining the loads (permanent, live, climatic — snow and wind, seismic, technological) and their combinations, static and dynamic analysis, modal and seismic analysis in accordance with the codes in force, sizing and checking of structural elements (columns, beams, slabs, walls, foundations) according to the constituent material (reinforced concrete, steel, timber, masonry), ultimate and serviceability limit-state checks, as well as the sizing of reinforcement and connections — carried out based on the geometric and mechanical attributes of the elements in the structural model, at a geometric and information level of detail (LOG/LOI) matched to the design phase and to the applicable codes (CR codes, P100, SR EN — Eurocodes), in order to substantiate the structural solution, the structural technical reports and coordination with the other disciplines (architecture, MEP, geotechnics).

Using the information models to check compliance with the minimum direct-sunlight durations required by the regulations in force, both for the proposed building and for the neighboring buildings it affects — calculating the direct-sunlight duration for the relevant rooms of the proposed building (living rooms, spaces with specific sunlight requirements), analyzing the shading cast by the proposed building on neighboring buildings and plots, analyzing the shading cast by the existing built context on the proposed building, checking compliance with the minimum sunlight duration on the reference date (21 February / 21 October, per Order 119/2014) and generating the associated graphic and numeric documentation (sunlight diagrams, shading maps, views for characteristic times of day) — based on the geometry of the proposed building and the georeferenced context model (existing neighboring buildings, topography), at a level of detail (LOG/LOI) matched to the design phase and to the applicable regulations, in order to substantiate the building's siting and massing solution and the documentation for approvals (DSP approval, building permit, PUD/PUZ documentation).

Using the information models to analyze the solar radiation incident on the building envelope, to substantiate the engineering energy-consumption calculations — calculating the solar radiation incident on façades, glazing and roofs (hourly, daily, seasonal, annual), analyzing solar gains through the transparent envelope elements and their impact on cooling and heating loads, studying passive shading systems (horizontal and vertical brise-soleil, setbacks, overhangs, vegetation), studying active shading systems (blinds, roller shades, automated systems), analyzing the efficiency of shading devices over characteristic periods (warm vs. cold season) and integrating the results into the building's energy-performance calculation — based on the envelope geometry, orientation and optical properties of the elements (solar factor g, light transmittance, absorption coefficient) from the architecture models, at a level of detail (LOG/LOI) matched to the design phase, in order to substantiate the envelope and shading solutions and to optimize the building's energy consumption.

Using the information models to analyze the thermal performance of the building envelope and calculate the global thermal-insulation coefficient (G/G1) — identifying the envelope elements (exterior walls, floors, terraces, roofs, windows, doors), calculating the thermal resistances (R) based on the layered build-ups, calculating thermal bridges (Ψ, χ), calculating G/G1 and comparing with the normed values GN/G1N — based on the thermal attributes of the elements in the architecture models, at a level of detail (LOG/LOI) matched to the design phase and to the applicable regulations, in order to substantiate the envelope solutions in the early design phases.

Using the information models to assess the building's sustainability performance by connecting model elements to material and system databases containing environmental attributes (Environmental Product Declarations — EPD, embodied carbon, recycled content, service life, reuse/recycling potential), in order to generate life-cycle assessment (LCA) reports and other specific evaluations — embodied and operational carbon footprint, resource consumption, construction and demolition waste management, energy and water performance, indoor environmental quality, integration into the urban and natural context — as well as to substantiate the documentation needed to obtain sustainability certifications (BREEAM, LEED, DGNB, Level(s), Green Homes, etc.). The analyses are carried out based on the attributes and classifications associated with the elements in the discipline models, at a level of detail (LOG/LOI) matched to the design phase and to the targeted certification scheme, in order to substantiate low-environmental-impact design solutions and to obtain the associated certification scores.

Using the information models to analyze the building's energy performance, substantiate the renewable-energy supply solutions and verify compliance with nearly Zero-Energy Building (nZEB) requirements. Based on the climate zone, the envelope performance (CUB10), the function and the number of users, by generating an energy model (BEM — Building Energy Model) derived from the native information model, the objective's energy-consumption requirement is analyzed and established. Based on this requirement and the site-specific conditions, the type, positioning and sizing of renewable-energy sources (PV, solar thermal panels, geothermal systems, wind systems, heat pumps, etc.) are analyzed. In addition, the model can support nZEB compliance checking by tracking specific indicators — total primary-energy consumption, the minimum share of renewable energy in total consumption, envelope thermal performance (including airtightness), MEP-system efficiency — in correlation with Law 372/2005 on the energy performance of buildings and the applicable technical regulations, in order to substantiate design solutions, energy-certification documentation and the energy audit.

Using information models and computational methods to automatically generate, modify, check and optimize the geometry, data and relationships in the model based on predefined rules, parameters and algorithms — parametric geometry generation (forms, configurations, repetitive patterns, complex surfaces defined by mathematical rules), generative design (automatically exploring multiple solution variants based on defined objectives and constraints), automation of repetitive modeling tasks (serial placement of elements, populating with furniture or equipment, generating repetitive structures), bulk manipulation and transformation of the data associated with model elements (assigning properties, renaming, reclassifying), optimizing solutions based on multiple criteria (energy, cost, structural, functional performance), as well as integration with analysis and calculation tools through bidirectional data transfer — carried out through visual programming environments (Grasshopper, Dynamo or equivalent) or application programming interfaces (API), based on the discipline models, at a level of detail (LOG/LOI) matched to the design phase and the purpose of the analysis, in order to increase productivity — including in relation to CUB34 — reduce manual errors and substantiate design decisions through the systematic exploration of solutions.

Using the information models to substantiate the technical solutions for interior plumbing installations — sizing the cold and hot domestic water distribution networks (design flows, diameters, velocities, pressure losses, ensuring pressures at consumers), sizing the domestic hot-water production system (boilers, exchangers, recirculation), sizing the interior domestic sewerage installations (flows, diameters, slopes, stack venting), sizing the interior stormwater installations (roof drains, stacks, collectors), sizing the water-based fire-suppression installations (interior hydrants, sprinklers, deluge, minimum reserve), and checking the sanitary provision against the function and the number of users — based on the geometric and hydraulic attributes of the elements in the plumbing models, at a level of detail (LOG/LOI) matched to the design phase and to the applicable regulations, in order to substantiate the design solutions, technical reports and coordination with the other disciplines.

Using the information models to substantiate the technical solutions for water and sewerage utility networks — sizing the water-supply networks (flows, diameters, pressures, pressure losses), sizing reservoirs and pumping stations, calculating foul, storm or combined sewerage networks, sizing ancillary structures (chambers, separators, retention basins) and treatment plants, hydraulic analysis of the network (steady-state and transient simulations), carried out based on the geometric and hydraulic attributes of the elements in the utility models, at a level of detail (LOG/LOI) matched to the design phase and to the applicable regulations, in order to substantiate the design solutions, technical reports and coordination with the other disciplines.

Using the information models to substantiate the technical solutions for ventilation and air-conditioning installations — calculating cooling and heating loads per room and per thermal zone, calculating the required air flows (hygienic ventilation, pollutant extraction, make-up), sizing the air-handling equipment (air-handling units, indoor/outdoor units, heat-recovery units), sizing the ventilation ductwork (sections, velocities, pressure losses) and refrigerant piping, sizing the smoke-extraction systems in case of fire, analyzing indoor air quality and thermal comfort (temperature, humidity, air velocity), and checking the system's energy efficiency — based on the geometric and thermal attributes of the elements in the architecture and HVAC models, at a level of detail (LOG/LOI) matched to the design phase and to the applicable regulations, in order to substantiate the design solutions, technical reports and coordination with the other disciplines.

Using the information models to substantiate the technical solutions for heating installations — calculating the heat demand per room and for the whole building (heat losses through transmission and ventilation, heating loads), sizing the heat source (thermal plants, heat pumps, heat exchangers, connection to a district system), sizing the heating units (radiators, fan-coils, underfloor/ceiling/wall heating systems), sizing the heat-carrier distribution networks (diameters, flows, velocities, pressure losses, hydraulic balancing), sizing the pumping systems and expansion vessels, analyzing the system's energy efficiency and operating regime, carried out based on the geometric and thermal attributes of the elements in the architecture and thermal-installation models, at a level of detail (LOG/LOI) matched to the design phase and to the applicable regulations, in order to substantiate the design solutions, technical reports and coordination with the other disciplines.

Artificial lighting analysis involves using the information models to check the lighting system's performance against the functions of the spaces — calculating the maintained average illuminance on the working plane, checking illuminance uniformity, analyzing luminance and the glare index (UGR), checking the color-rendering index (CRI) and color temperature, analyzing luminous-flux distribution and luminaire efficiency, calculating safety and escape lighting, and analyzing the lighting system's energy efficiency (LENI — Lighting Energy Numeric Indicator) — carried out based on the space geometry, the reflectance of the finishes and the photometrics of the luminaires (IES/LDT files) associated with the elements in the architecture and electrical models, at a level of detail (LOG/LOI) matched to the design phase and to the applicable regulations, in order to substantiate the lighting solutions, technical reports and coordination with the electrical discipline.

Analysis and sizing of the power (LV) and extra-low-voltage electrical network involves using the information models to substantiate the technical solutions for electrical installations — circuit-sizing calculations (cable cross-sections, protections, voltage drops), the energy balance and the calculation of installed and absorbed power, short-circuit analysis and protection checking, lighting calculation (illuminance levels, uniformity, color-rendering indices), sizing of protection installations (earthing, lightning protection, surge protection), as well as sizing of extra-low-voltage systems (data networks, fire detection and alarm, access control, video surveillance) — carried out based on the attributes and topology of the elements in the electrical models, at a level of detail (LOG/LOI) matched to the design phase and to the applicable regulations (I7, NP-061, NTE, etc.), in order to substantiate the design solutions, technical reports and coordination with the other disciplines.

Using the information models to substantiate other engineering analyses and calculations that do not fall within the scope of the CUBs explicitly dedicated to a discipline, but which may be needed depending on the specifics, complexity or purpose of the project — acoustic analyses (airborne and impact sound insulation, reverberation time, noise maps for spaces with special requirements such as concert halls, conference rooms, educational spaces), computational fluid dynamics (CFD) analyses for the study of interior and exterior airflow (thermal comfort, natural ventilation, pollutant dispersion, wind loads), smoke- and fire-spread analyses for buildings with special fire-safety requirements, evacuation analyses (pedestrian-flow simulations in public buildings, events, transport), vibration analyses (from traffic, machinery, industrial activities), advanced geotechnical analyses (soil–structure interaction, differential settlements), durability analyses of materials and building elements, as well as other project-specific multidisciplinary analyses — carried out by transferring data from the information models to specialized calculation applications, at a level of detail (LOG/LOI) matched to the design phase and to the specific requirements of the analysis, in order to substantiate scientifically argued design decisions and comply with the project's special requirements.

3D coordination and clash detection involves the integrated checking of the information models from the different disciplines (architecture, structure, MEP, utility networks, engineering works, etc.) by federating them into a coordinated model and automatically identifying conflicts — hard geometric clashes (physical overlaps between elements, e.g. ductwork crossing a beam), tolerance clashes (e.g. a window opening blocked by a column, or the serviceability space for an AHU obstructed by other services) and temporal clashes (e.g. there is no longer room to install the built equipment and/or systems). The geometric and information level of detail (LOIN) must be sufficient for clash detection.

Using the information models to automatically/semi-automatically check their compliance with the project's information requirements and with the functional and technical requirements assumed through the concept note and design brief — checking compliance with the information requirements (EIR — Exchange Information Requirements), checking the structure and classifications of model elements (names, attributes, property sets), checking information completeness at each exchange point (data drop), checking functional conformance with the design brief (areas, functions, amenities, functional indicators), checking compliance with the techno-economic indicators assumed through the concept note, checking adherence to the modeling rules (naming conventions, file structure, coordinate systems) and generating compliance reports managed in the common data environment (CDE) — carried out through automated checking tools (model checking) based on coded rule sets (for example, via IDS — Information Delivery Specification), at a level of detail (LOG/LOI) matched to the design phase, in order to ensure the information quality of the BIM and openBIM deliverables and to substantiate the client's model-acceptance decisions.

Compliance with hygiene, health and the environment involves using the information models to check adherence to the essential requirements applicable to the building regarding occupant health and environmental protection — indoor air quality (ventilation, pollutant extraction, humidity control), natural and artificial lighting of occupied spaces, hygrothermal and acoustic comfort, wastewater and waste management, use of materials with low health impact (VOC classifications, product certifications), as well as integration into the natural environment (permeable surfaces, green spaces, stormwater management, biodiversity impact) — based on the attributes and classifications associated with model elements, at a level of detail (LOG/LOI) matched to the design phase and to the applicable requirements of the legislation in force (Law 10/1995 — essential requirement C, hygiene regulations, environmental-protection regulations), in order to substantiate the design solutions and the documentation for environmental approvals and agreements.

Using the information models to analyze and check the safety and accessibility solutions in the use of the building and the site — analyzing pedestrian access (stairs, ramps, landings, clear circulation widths), checking accessibility for people with disabilities (maneuvering clearances, specific provisions), analyzing safety-in-use elements (handrails and parapets, anti-slip surfaces, snow guards), analyzing vehicular access and circulation (turning radii, gradients, clearances, visibility) and sizing the parking (number and type of spaces, spaces dedicated to people with disabilities and to electric vehicles) — carried out based on the geometric attributes of the elements in the architecture, site-grading and roads models, at a level of detail (LOG/LOI) matched to the design phase and to the applicable regulations, in order to substantiate the design solutions, technical reports and documentation for approvals.

Using the information models to analyze and substantiate the fire-protection and fire-safety solutions — analyzing the evacuation flows and routes (clear widths, maximum evacuation distances, number of flows, sizing of doors, stairs and escape routes), analyzing fire compartmentation (delimiting fire compartments, maximum permitted areas, fire-resistant separating elements), checking the functions and their classification into stability levels and fire-risk classes, analyzing the access of intervention forces (roads and platforms for fire vehicles, access distances, water sources for firefighting), checking the provision of detection, alarm and fire-suppression installations (correlation with the MEP models), analyzing the smoke and hot-gas extraction systems (natural or mechanical smoke control), and checking the safety lighting and evacuation markings — carried out based on the geometric and functional attributes of the elements in the architecture and MEP models, at a sufficient level of detail (LOG/LOI) and with the applicable regulations, in order to substantiate the design solutions, the fire-safety scenario and the documentation for the fire-safety approval/permit.

The process of generating deliverables — the technical documentation extracted from the information models (native, federated or integrated) — 2D drawings (plans, sections, elevations, details, MEP schematics, longitudinal and cross profiles, axonometrics, developed views, etc.) directly from the information model(s), where 2D graphic elements such as hatches, lines, etc. will, wherever possible, be referenced to the 3D elements. This BIM use case is considered transitional, until legislation is updated and Digital Building Permits based on BIM and openBIM models are adopted at scale. Information from the model(s) can be extracted and connected to the written documents (bills of quantities, technical specifications and equipment sheets, coordination reports) according to the capabilities of the BIM authoring/management tool.

Quantity take-off involves obtaining, directly from the information models, the quantities of elements, materials and works needed to substantiate the bills of quantities — geometric quantities (lengths, areas, volumes), quantities by element category (number of pieces, mark, diameters, weights, as applicable) and quantities by work category. These can be correlated with cost-estimate items (emerging CUB) — extracted based on the attributes and classifications associated with model elements, at a level of detail (LOG/LOI) matched to the design phase, in order to obtain quantities that are verifiable and traceable to source.

Visualization and marketing involve using the information models to produce presentation and communication materials for the client, decision-makers and the general public — photorealistic static renderings (exterior and interior), animations and fly-throughs, 360° panoramic views, interactive digital mock-ups, virtual reality (VR) and augmented reality (AR) experiences, as well as graphic presentation materials for public consultations, approvals or project promotion — generated from the discipline models (especially architecture, site grading and exterior works), at a level of detail (LOG/LOD) matched to the intended communication purpose, without substituting the technical role of the design models and without constituting a source for quantity take-off or compliance checking.

Using the information models to estimate project costs by associating the quantities extracted from the model (CUB30) with cost information from specialized databases or cost-estimate items — estimating costs by work and material category, substantiating the general estimate and the per-object estimates according to the structure of Government Decision 907, estimating by design phase with an uncertainty level matched to the maturity of the information, comparative analysis of alternative solutions, tracking cost evolution between phases and integration with the techno-economic indicators assumed through the funding application — carried out based on the attributes and classifications associated with the elements in the discipline models, at a level of detail (LOG/LOI) matched to the design phase, in order to substantiate design decisions and funding documentation, with the note that the information flows are not connected (emerging).

Using openBIM information models to obtain approvals and the building permit through automatic/semi-automatic checking of compliance with norms, urban-planning regulations and applicable legislation (model checking/code checking) — checking urban-planning conformity, checking functional and dimensional compliance against the regulations specific to the building type, checking adherence to easements and protection zones (roads, utility networks, monuments, protected natural areas) and transmitting the models and documentation to the issuing authorities through dedicated digital platforms — carried out based on the geometric and semantic attributes of the elements in the discipline models (especially architecture, site grading and topography), at a level of detail (LOG/LOI) matched to the design phase (DTAC) and to the specific requirements of the issuing authorities, in order to streamline the approval/permitting process, reduce errors and ensure the traceability of the checks.

Using the information models to generate the digital information needed to fabricate materials, elements and assemblies in an industrialized process — direct transfer of geometry and attributes from the information model to the fabrication equipment (CAM — Computer-Aided Manufacturing), generating specific fabrication files (CNC, laser/waterjet/plasma cutting, additive manufacturing/3D printing, rebar cutting and bending), detailing prefabricated elements (façade panels, precast concrete or steel structural elements, volumetric modules, joinery, custom furniture), integration with the factories' production flows (planning, raw-material management, batch tracking), traceability of the fabricated elements through digital markers (QR codes, RFID) correlated with the information model, and logistical coordination of delivery and on-site assembly — carried out based on the geometric and technical attributes of the elements in the discipline models, at a level of detail (LOG/LOI) appropriate to fabrication (typically LOD 400 or equivalent), in order to reduce execution errors, optimize material consumption, shorten execution durations and ensure the consistent quality of the produced elements.

Using 4D information models (a 3D model of the project's permanent elements correlated with the time dimension) to plan the construction sequence of the objective — associating model elements with the execution-schedule activities (model–WBS–Gantt link), visually simulating the works over execution phases, identifying dependencies and temporal conflicts between activities, analyzing alternative execution scenarios and optimizing durations, planning occupation or remodeling/extension phases while maintaining functionality in unaffected areas, and visually communicating the execution plan to the client and stakeholders — carried out based on the attributes of the elements in the discipline models, correlated with the execution schedule, at a level of detail (LOG/LOI) matched to the design phase, in order to substantiate execution decisions and optimize the project calendar.

Using the information models to graphically plan the site organization during execution — using CUB1, 2, 3, 4 (the existing site elements that influence execution — soil, buildings, vegetation, utility networks, accesses), planning the placement and movement of machinery (cranes, concrete mixers, excavators — with action radii and clearances), planning the circulation flows on site (supply access routes, pedestrian circulation, parking areas), managing the evolution of the site organization over execution phases (different configurations for different work phases), estimating the costs and resources associated with the site organization (labor, materials, equipment rentals), and analyzing safety risks and interferences with the neighborhood — carried out based on the geometric attributes of the existing, temporary and proposed elements, at a level of detail (LOG/LOI) matched to the project phase and the complexity of the site, in order to substantiate the site-organization design, reduce logistical risks and optimize site costs.

Using the information models to design and analyze the auxiliary construction systems needed to carry out the works — designing formwork, scaffolding and staging, temporary shoring and supports, complex glazing and façade systems, lifting and handling systems for elements, analyzing interferences with the permanent elements, structural checking of the temporary systems and planning the use and reuse of components — carried out based on the attributes of the elements in the discipline models, correlated with CUB36 (site organization) and CUB35 (phase planning), at a level of detail (LOG/LOI) appropriate to execution, in order to optimize the execution solutions, reduce the costs of auxiliary systems and ensure safety.

Using the information models to monitor, control and manage the execution of construction works — tracking physical progress by periodically updating the 'as-built' model and comparing it with the 'as-planned' model, capturing the real state of execution through reality-capture technologies (LIDAR scanning, photogrammetry, drones, 360 cameras), checking the conformity of execution with the technical specifications and applicable regulations, identifying geometric and qualitative deviations from the model and reporting in the common data environment (CDE), substantiating payment applications by correlating the executed quantities with the schedule and the estimate, managing quality control (tests, trials, conformity certificates) and site-safety requirements, and reporting the status to the client and stakeholders — carried out based on the attributes of the elements in the discipline models, correlated with CUB35 (phase planning) and CUB36 (site organization), at a level of detail (LOG/LOI) appropriate to execution, in order to rigorously control quality, costs and deadlines.

Using the information models to faithfully represent the real physical conditions of the building's component elements upon completion of execution — updating the design model with the changes that occurred during execution (site instructions, dimensional variations), capturing the final state of the building through reality-capture technologies (LIDAR scanning, photogrammetry, drones), enriching the elements with operation-specific information (manufacturer, brand, model, serial number, commissioning data, estimated service life), attaching the technical documentation (data sheets, conformity certificates, declarations of performance, use and maintenance instructions, warranties), structuring the information according to exchange standards for operation (e.g. COBie), and transferring the data to specialized asset-management systems (CAFM, CMMS, IWMS) — carried out based on the validated final execution model, at a level of detail (LOG/LOI) appropriate to operation, in order to constitute a digital asset of the building that supports the subsequent operation and maintenance processes.