Building Information Model

Goals Give an introduction to the core concepts of parametric CA(A)D and Building Information Modeling (BIM)

After this session you should … … have basic ideas about the fundamental concepts of Computer Aided Design and Building Information Modeling (BIM) … be aware of benefits and problems of BIM

Introduction to CA(A)D and BIM: Overview Introduction to CA(A)D and BIM: The history why CAD? The problems What’s wrong with today’s CAD? The promises What can the application of the BIM paradigm do about it? The real world what does actually work today?

Building Information Model Information Exchange Overview Conventional CA(A)D Parametric modeling Adaptable geometry Adaptable representation Building Information Model Information Exchange

Conventional CA(AD)

Goals Pipe=pijp

This is not music - Semiotics

This is not a building

Ogden-Richards triangle of meaning

Ogden-Richards triangle in CAAD

Communication and Information Exchange Shannons communication model

Means of communication in the AEC domain Conceptual sketches Scale models Oral descriptions (telephone, meeting…) Written descriptions Plans, elevations, sections Details …

Concept drawings/sketching

Invention of descriptive geometry History: 325 BC–265 BC Euclid The Elements Inventor of the coordinate system, ‘father’ of geometry

Invention of descriptive geometry History: 1435 Leone Battista Alberti De pictura First scientific work describing central and orthogonal perspective

Invention of projective geometry History: 1591-1661 Gérard Desargues Invention of projective geometry

Invention of the modern CAD concept History: 1960 Ivan Sutherland SKETCHPAD 1982 AutoCAD 1.0 introduced on COMDEX Sketchpad demo

Invention of parametric curves for the use in computer graphics Pierre Bézier [1910-1999] Invention of parametric curves for the use in computer graphics UNISURF CAD application devd. for Renault on Bézier- curves in the 1960's “If your system were that good, the Americans would have invented it first!” (Management of Renault to B. in 1971)

CA(A)D packages The promises: Let repetitive work be done by the machine Draw more exactly Draw quicker Concentrate on the building instead of the drawing Get rid of paper by electronic documents Let ‘intelligent’ functionality take care of certain tasks (automation)

The real world: CA(A)D packages CA(A)D in most cases used as 2D pen and paper replacement Document exchange critical due to lack of standards Applications are error-prone

Conventional design document creation

Design documents over lifecycle of a building

Nature of the Building and Construction Industry Very fragmented industry For example, in the EU (statistics 2000): 11 million jobs, 2 million companies 93% of companies less than 10 employees Only 100 companies with more that 2000 employees (source: Arto Kiviniemi)

Communication in the AEC/FM domain

Building Information Model Chuck Eastman Building Information Model "Building information modeling integrates all of the geometric model information, the functional requirements and capabilities, and piece behavior information into a single interrelated description of a building project over its lifecycle. It also includes process information dealing with construction schedules and fabrication processes."

Building Lifecycle according to Gielinghs Stages

Communication and Knowledge Exchange Then?

Building information model paradigm Building is designed assembling parametric objects that are related to each other Every object of the building has a set of properties that can be interpreted in different contexts Geometrical representations (e.g. drawings) are only one of many aspects. Drawings can be generated dynamically from existing data. Changes to the model are reflected in all depending documents Different domains (structural engineering, building physics etc.) have different views on a building model

Parametric Modeling

Conventional drawing of a rectangle P1 : x=1, y=1 P2 : x=6, y=1 P3 : x=6, y=4 P4 : x=1, y=4

Parametric drawing of a rectangle Parameters: (input from modeler) Object type : Rectangle Width : 5 Height : 3 Center Point C : x = 3.5 , y = 2.5 Application calculates explicit geometry: P1 = x = x-coordinate of point C – width / 2, y = y-coordinate of point C – height / 2 P2 = x = x-coordinate of point C + width / 2, y = y-coordinate of point C – height / 2 P3 = x = x-coordinate of point C + width / 2, y = y-coordinate of point C + height / 2 P4 = x = x-coordinate of point C - width / 2, y = y-coordinate of point C + height / 2

Non-parametric building elements Window as non-parametric geometry: When size of window is manipulated by scaling, the profiles of the window frame are scaled as well Each part of the frame has to be adjusted Many operations are necessary => time and errors Hint: you can actually use “stretching” in a 2D-case to prevent this

Parametric Windows in BIM / CAAD packages: ADT

Parametric Windows in BIM / CAAD packages: Revit

Parametric Windows in BIM / CAAD packages: Archicad

Custom parametric objects Circumference = number of chairs x 0 .60cm

Image source: ONL

Image source: ONL

Image source: ONL

Image source: ONL

Different representations of parametric objects Low detail 1:100 Medium detail 1:50 High Detail 1:50

Different representations of parametric objects

Different representations of parametric objects

Different representations of parametric objects

Building Information Model

Building information model paradigm

Central Building Information Model

Facilities Management BIM Conversion 2D -> BIM Model CAD 3D + Facilities Management Electrical domain Thermal HVAC Collision detection Source: German IAI for building Services

Building information model paradigm Advantages ‘intelligent’ applications can gather all sorts of information (room sizes, material lists etc.) from a well defined model Dependent drawings such as sections do not have to be redrawn on changes but automatically adapt

Building information model paradigm Problems Additional (non-graphical) information has to be provided by architect Coherency when changing objects Object relations have to be designed Complexity with all data required often cannot not be generated at design time

Information Exchange Interoperability

Islands of Automation

CAAD applications in the architectural domain Marketshare CAAD-packages (Germany 2003) according to online survey on www.aecweb.de

Software applications in Building and Construction Commercial Free alternative Typical exchange format by extension Sketching / Early planning / modeling Rhinoceros 3D, Facility Composer SketchUp Wings 3D Blender *.skp, *.3ds, *.dxf, *col, *.wrl Architectural Design Autodesk Architectural Desktop Autodesk Revit Arch. Graphisoft Archicad Bentley Triforma Nemetscheck Allplan Open Cascade - based *.dxf, *.dwg, *.ifc, *.rvt, *.dgn, *.stp, *.iges Structural Tekla, Bentley structures, Ansys, STRUDL, Marc-Mentat Dxf, CIS/2, IFC Energy Performance Analysis IES VABI Ecotect Energy+ Esp-r *dxf, *.ifc, others Visualization / Animation Autodesk 3DS Max / Viz Autodesk Maya Maxon Cinema 4D *.max, *.3ds, *.blend, *.obj, *.c4d Layout / Graphics Adobe Illustrator Adobe Photoshop Corel Photopaint Inkscape Gimp Scribus *ai, *.eps, *.svg, *. dxf, *.png, *.jpg, *.bmp, *.gif, *.emf

Software applications in Building and Construction Commercial Free alternative Typical exchange format by extension Sketching / Early planning / modeling Rhinoceros 3D, Facility Composer SketchUp Wings 3D Blender *.skp, *.3ds, *.dxf, *col, *.wrl Architectural Design Autodesk Architectural Desktop Autodesk Revit Arch. Graphisoft Archicad Bentley Triforma Nemetscheck Allplan Open Cascade - based *.dxf, *.dwg, *.ifc, *.rvt, *.dgn, *.stp, *.iges Structural Tekla, Bentley structures, Ansys, STRUDL, Marc-Mentat Dxf, CIS/2, IFC Energy Performance Analysis IES VABI Ecotect Energy+ Esp-r *dxf, *.ifc, others Visualization / Animation Autodesk 3DS Max / Viz Autodesk Maya Maxon Cinema 4D *.max, *.3ds, *.blend, *.obj, *.c4d Layout / Graphics Adobe Illustrator Adobe Photoshop Corel Photopaint Inkscape Gimp Scribus *ai, *.eps, *.svg, *. dxf, *.png, *.jpg, *.bmp, *.gif, *.emf

Software applications in Building and Construction

Layers Structuring drawings Easy metaphor for architects (stacked transparent paper) Currently most standardize method of data exchange structuring ISO DIS 13567 AIA standard Easy to handle Unlimited granularity

Standard exchange formats DXF Most established, open standard for data exchange to date, interfaces build into many applications Human readable ASCII format Limited set of geometry and information Only faces/polygons supported No advanced geometry such as solids and NURBS

Standard exchange formats DWG Proprietary Autodesk format with frequent changes Can be im-/exported by many applications Features advanced geometry (Solids etc.) Can be extended by 3rd party applications

Standard exchange formats IFC Developed to suit needs of building industry Open Extendable Lots of advanced meta-data storable Not widely supported (yet) Under development / constant change XML-version human readable and easy to integrate for collaboration with other applications

IFC overview

Some properties of an IFC Window ENTITY IfcWindow; OverallHeight : OPTIONAL IfcPositiveLengthMeasure; OverallWidth : OPTIONAL IfcPositiveLengthMeasure; Reference : IfcIdentifier FireRating : IfcLabel AcousticRating : IfcLabel SecurityRating : IfcLabel IsExternal : IfcBoolean Infiltration : IfcVolumetricFlowRateMeasure ThermalTransmittance : IfcThermalTransmittanceMeasure GlazingAreaFraction : IfcPositiveRatioMeasure SmokeStop : IfcBoolean

Architect as ‘building programmer’? Future developments Architect as ‘building programmer’? Better compatibility through open standards (IFC etc.) Finally: Paperless office at last?

Eastman “Building Product Models” 1999 CRC Press Ltd. Literature Eastman, Teichholz, Sacks, Liston: “BIM Handbook”, 2008, John Wiley & Sons Inc. Eastman “Building Product Models” 1999 CRC Press Ltd. Jernigan “Big BIM, little bim” 2007, 4Site Press “ik bim, jij bim-t, wij bim-men” 2008,Center for Process Innovation in building & construction