BIM.02integrated cost budgeting and cost

estimating model for building projects

sarmad al-mashtadr. sabah alkass

Author BiographyDegree: M.A.Sc. Building Engineering

B.Sc. Architectural Engineering

University: Concordia UniversityUniversity of Baghdad

Years of Experience: 16

Professional Field: Architectural designInterior Design

Tools Developed: Fenestration Management SystemAutomated Cost EstimationCPI 3D VisualizationRisk Registrar

agenda

introduction literature reviewproblem statement

methodology

proposed model

case study

conclusion

assembly costingmapping different WBS

research contributionresearch limitation

introduction

scope

objectives

research

building projectsassets cost

streamline cost estimate processintegrated model

cost estimates class 1/2 AACEmultiple WBS simultaneouslymultiple cost sources

AACE classification

6

work breakdown structure (WBS)

deliverable-oriented hierarchy of decomposed project components that organizes and defines the total scope of the project(PMI)

7

literature review

WBS types (CSI and CSC)functional elements of buildingowner, designer, or general contractorUniformat™

materials & methods or “work results”specifier or subcontractorMasterFormat™

productsproduct representative

8

Estimating Process

WBS

input process output

cost estimate

quantity take-off

cost data lookup

project design

cost data

calculate

group & classify

9

automated quantity take-offCAD based

2D, requires user input of 3D dimension3D geometric data, generic solids require user input to identify object type

BIM basedfull object oriented 3D geometric dataParametric environment, data replication

10

types of quantitiesproduct/procurement quantities (PPQ)

physical material quantities part of final building productdetermined by the design

length and weight of rebar, volume of concrete beams, areas of metal decking

11

types of quantitiesProcess of Construction Quantities (PCQ)

depend on construction process/methods, specific conditions of jobbased on

more detailed breakdown of associated PPQsproductivity factors, ex. locations, geometric characteristics, construction methods

shoring/scaffolding, areas of formwork, labour hours for hanging drywall, and excavation quantities for earthwork

12

Traditional vs. Automated

2D paper drawings from design/

engineering team

2D paper drawings from design/

engineering team

Manual takeoff and manual check for

“conditions”

Manual takeoff and manual check for

“conditions”

Estimating SoftwareEstimating Software

Manually associate take-off info. with assembly items

Manually associate take-off info. with assembly items

Associate digitized take-off info. with

component

Associate digitized take-off info. with

component

3D/BIM models from

project

3D/BIM models from

project

Extract quantities within BIM tool

Extract quantities within BIM tool

Manually extract quantities with

specialized take-off / estimating tool

Manually extract quantities with

specialized take-off / estimating tool

Associate with assembly itemsAssociate with assembly items

Auto-extract and associate with

assembly items

Auto-extract and associate with

assembly items

Calculation of additional

quantities item properties

Calculation of additional

quantities item properties

Cost database

Cost database

Supplier / subcontractor

pricing

Supplier / subcontractor

pricing

EstimateEstimate

Traditional paper-based estimating process

Automated estimating process

Manual link, changes must be updated by estimator

Digital link, changes updated automatically

13

problem statementcost estimate is time consuming task

performed at distant points leaving gaps

lack of framework and methodology for automated detailed cost estimating

automated quantity take-off for PCQuse of TWBS….

14

methodology

assembly costing

components that are commonly encountered in the construction are viewed as estimating group (Halpin)

assembly costing

component 1component 2

component 3component 4component n

assembly cost

assembly cost

materia

ls

materia

lsequipment

equipmentlabour

labour

17

mapping EWBS to TWBS

assembly cost

assembly cost

materialsmaterials

equipmentequipment

labourlabour

component 1

materialsmaterials

equipmentequipment

labourlabour

component 2

materialsmaterials

equipmentequipment

labourlabour

component n

18

mapping EWBS to TWBS

UniFormat: System B1010 219 3000: BM. & Slab One way 15’x15’ Bay, 40 PSF S. Load, 12” Min. Col.

UniFormat: System B1010 219 3000: BM. & Slab One way 15’x15’ Bay, 40 PSF S. Load, 12” Min. Col.

Forms In Place, Flat Plate to 15’ High, 4 usesForms In Place, Flat Plate to 15’ High, 4 uses

Reinforcing in place, elevated slabs #4 to #7Reinforcing in place, elevated slabs #4 to #7

Concrete Ready mix, regular Weight 3000 psiConcrete Ready mix, regular Weight 3000 psi

Place and vibrate concrete, elevated slab less than 6”, pump

Place and vibrate concrete, elevated slab less than 6”, pump

19

proposed model

proposed model components

Database Solution

CAD/BIMWith quantity take-off module

21

AssembliesAssemblies

Cost Estimates(Assemblies)

Cost Estimates(Assemblies)

CAD/BIMCAD/BIM

Cost Data(3rdParty)Cost Data(3rdParty)

TWBS(MasterFormat)

TWBS(MasterFormat)

Cost Estimates(Trades)

Cost Estimates(Trades)

Cost Data(In-house)Cost Data(In-house)

EWBS(UniFormat)

EWBS(UniFormat)

ComponentsComponents

22

proposed model design (simplified)

proposed model designEWBS componentsEWBS components TWBS componentsTWBS components

B.O.QB.O.Q

Cost Estimates(Assemblies)

Cost Estimates(Assemblies)

System CoreFunctions

(Set-1)

System CoreFunctions

(Set-1)

CAD/BIMCAD/BIM

EWBS(Other)EWBS

(Other)

Cost Data(3rdParty)Cost Data(3rdParty)

TWBS(Other)TWBS

(Other)

TWBS(MasterFormat)

TWBS(MasterFormat)

Assemblies ComponentsAssemblies

Components

Cost Estimates(Trades)

Cost Estimates(Trades)

GACGACSystem Core

Functions(Set-2)

System CoreFunctions

(Set-2)

GenericGeneric

Cost Data(In-house)Cost Data(In-house)

EWBS(UniFormat)

EWBS(UniFormat)

SCMLSCML

23

How it Works

24

proposed model topology

25

step I: cost data processing

cost data(RS Means)

cost data(In-House)

EWBS

input process output

GAC

Standardize(assemblies)

MapStandardize(assemblies)

SCML

Standardize(Sys. Components)

Standardize(Sys. Components) Map

TWBS

26

step II: quantity take-off

geometrical data

GAC

user(CAD/BIM GUI)

elemental B.O.Q.

link(assembly code)

input process output

data export(ODBC)

27

step III: cost calculation

elemental B.O.Q.

SCML

GAC

elemental cost

cost data lookup

input process output

trade costmapping(EWBS to TWBS)

cost data lookup

calculate

calculate

28

step IV: cost estimate reporting

elemental cost

trades cost

user(RDBMS GUI)

elemental cost reports

trades cost reports

group & classify

input process output

29

cost estimate reportsEWBS cost estimate level 5EWBS cost estimate level 4assemblies with no cost dataTWBS cost estimate level 5TWBS cost estimate level 4TWBS cost estimate level 5 by EWBSTWBS cost estimate level 4 by EWBS

30

research contributionsIntegrated model streamline cost estimate process

cost monitoring for design phases

framework multiple simultaneous WBSmultiple cost data sources

addressing particular limitations of current 3D modelling technologies

detailed quantity take-off from generic model

31

research limitation

assembly unit cost hides the productivity factor

no optimization

no consideration for the schedule effects

32

quick democase study

?

33

case study projectquick demo

34

linking BIM object to GAC entry

35

EWBS cost estimate report snapshot(level 4)

36

EWBS cost estimate chart(level III)

37

TWBS cost estimate report snapshot(level 4)

38

Questions ?

thank you