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

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?

Overview

● Conventional CA(A)D● Parametric modeling

– Adaptable geometry– Adaptable representation

● Building Information Model● Information Exchange

●Conventional CA(AD)

Goals

This is not music - Semiotics

This is not a building

Ogden-Richards triangle of meaning

Thought or reference

Symbol Refferent

refers to

sym

bolis

es

stands for

Design / engineering solution

Drawing / model / text Building

refers to

sym

bolis

es

stands for

Ogden-Richards triangle in CAAD

Communication and Information Exchange

Information Source

Transmitter Receiver Destination

Noise Source

Message

Sign

al

Rece

ived

Sig

nal

Message

???

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

● History:– 1591-1661 Gérard

Desargues● Invention of projective

geometry

Invention of projective geometry

Invention of the modern CAD concept

● History:– 1960 Ivan Sutherland

SKETCHPAD– 1982 AutoCAD 1.0

introduced on COMDEX

Sketchpad demo

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)

CA(A)D packages

● The real world:– 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

Floor Plan

Sections

Eleveations

Perspective drawing3D model

Presentation / rendering

Bill of MaterialsContractingSchedulingConstructing

Using / MaintainingDemolishing

Detailing

Design documents over lifecycle of a building

Time

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

**

*

*

*

*

*

*

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

Construction planing “as planned” construction “as build”

Feasibility study“as

required”Design

“as designed”

Operation & Management “as used” Demolition planning“as

demolished”

Process

State

Communication and Knowledge Exchange

HVAC Engineer

Constr. Engineer

Building Owner

Civil Engineer

Structural Engineer

Facilities Manager

Energy Consultant

Architect

HVAC Engineer

Constr. Engineer

Building Owner

Civil Engineer

Structural Engineer

Facilities Manager

Energy Consultant

Architect

Shared Data Model

Now 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 (1,1) P2 (6,1)

P3 (6,4)P4 (1,4)

x

y

P1 : x=1, y=1P2 : x=6, y=1P3 : x=6, y=4P4 : x=1, y=4

C (3.5,2.5)

x

y width

heig

ht/

2

heig

htwidth / 2

Parametric drawing of a rectangle

Parameters: (input from modeler)

Object type : Rectangle Width : 5Height : 3Center 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

Geometric Properties

- Length

- Width

- Height

Material Properties

- Mass

Construction Type

- Insulation

- Load Bearing

15.33

0.40 m

3.70 m

120 kg/m3

No

Yes

Wall NS332

Geometric Properties

- Length

- Width

- Height

Material Properties

- Mass

- Conductivity

Product

- Manufacturer

- Price

…

1.5 m

1.22 m

2.00 m

20 kg/m3

0.84 J/s

Window Corp Inc.

2,500 EUR / piece

...

Window W2234

Is placed in

Central Building Information Model

BIM

Conversion2D -> BIM

Model CAD 3D +Facilities Management

Electricaldomain

Thermaldomain

HVACdomain

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 domainMarketshare CA(A)D

AutoCAD / ADT

ArchiCAD

SPIRIT

Nemetschek Allplan

Microstation

Vectorworks

ARRIBA / RIBCON

Other

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

Blender *.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

Blender *.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

Structuring drawings

● Layers– 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

Future developments

● Architect as ‘building programmer’?

● Better compatibility through open standards (IFC etc.)

● Finally: Paperless office at last?

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