Measuring the Impact of BIM in Design-Bid-Build

A Case Study

Dace A. Campbell, AIA, LEED AP // BNBuilders // 2 November 2011

The Associated General Contractors of America (AGC) is a

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by the AIA of any material of construction or any method or

manner of handling, using, distributing, or dealing in any material

or product. Questions related to specific materials, methods, and

services will be addressed at the conclusion of this presentation.

Significant work in collaborative, integrated delivery Integrated Project Delivery

Design-Build

GC/CM

Negotiated work

Key markets Life Science and Research

Healthcare / Medical Facilities

Public / Civic Spaces

Offices and Corporate Headquarters

Education (K-12 and Higher Education)

Mixed-Use Facilities

Hospitality

Commercial / Retail

BIM In use since 2006

Applied to $500M and 2M s.f. in new construction

Focus on PE’s and Supts as BIM users

Recognized as national and local leader

Founded in 2000

Headquartered in Seattle

San Francisco, San Diego, Portland, Montana

$300+ million in annual volume

250+ employees

$10K-$70M projects

National Recognition 2010 - ENR Top 400 Contractor

2009, 2008, 2007 - AGC of America

Construction Safety Excellence Award

2008 - Winner of AGC’s Grand Award for

Safety Excellence for Mid-Size Companies

2008 ENR Best of the Best Award for Project

Management

2008 AIA BIM Award

A Word About BIM…

BIM as simulation

Unlike manufacturing,

there is only one chance to “get it right” in construction

Mockups are expensive and time-consuming

BIM is a “virtual prototype”

Build it virtually to perfect the product and process

Simulate the building to:

Increase

Confidence

Understanding

Communication

Reduce Delivery time

Project cost

Waste

Injuries

Conflicts & RFIs

Why BIM?

Don’t do rework.

Do prework.

Position

BIM for 3-D MEP coordination Widely accepted as the “low-hanging fruit” entry into BIM

Clash detection is no longer enough

Before exploring ROI of other applications of BIM, have we truly measured its impact on 3D coordination? Some valuable studies into the impact of 3D coordination across

the industry, generally and anecdotally

There are few studies which objectively measure its true impact on a specific project

Every facility is unique Program, site, project team, etc.

BIM goes hand-in-hand with collaboration and integrated delivery BIM is rarely applied to hard-bid projects where collaboration is

often de-emphasized in favor of other factors.

BIM in Design-Bid-Build Case Study Project

This case-study presentation will discuss and analyze the

impact of BIM as applied in design-bid-build of a rural,

public, higher education facility

Spokane Falls CC Science Building

Spokane, WA

Construction: 2010-2011

$16.5M

75,000 s.f.

Science lab building at rural community college

BIM Considerations

BNB had no prior experience applying BIM to a public, low-bid project

Forward-thinking architect 3D coordination required in the spec

But only required for specific lab rooms with intense MEP systems

Handed over the Revit source model

Hard bid delivery method doesn’t encourage collaboration Subcontractors largely inexperienced,

disinterested in BIM

Little incentive to go beyond requirements in the spec

Desire by BNB to do more than the minimum with BIM But stronger desire to NOT lose money on

the project!

BIM Uses

0 Design Visualization

1. Surveying

2. Design Assistance & Constructability Review

3. Site Planning & Site Utilization

4. “4D” Scheduling and Sequencing

5. “5D” Model-Based Estimating

6. Subcontractor/Supplier Communications

7. Systems Coordination

8. Fabrication and Installation

9. Prefabrication

10.Operations and Maintenance

BIM Uses

0 Design Visualization

1. Surveying

2. Design Assistance & Constructability Review

3. Site Planning & Site Utilization

4. “4D” Scheduling and Sequencing

5. “5D” Model-Based Estimating

6. Subcontractor/Supplier Communications

7. Systems Coordination

8. Fabrication and Installation

9. Prefabrication

10.Operations and Maintenance

Design Visualization

Mech

Elec

FF&E

Arch

Struc

Lscape

Scope of 3D Coordination

8.7% of total floor area required by spec

Including Roof, we coordinated 37% of total area

~75% of the total MEP systems

~Density of MEP in these areas was 5 times that of the rest of the building

Plus (2)

rooms

on first

floor

Systems Coordination Good coordination requires:

Strong start -- Kickoff meeting to establish expectations and

protocols

Strong documents

Scope checklists

Model standards

Schedules

Designer participation – clarify/defend design intent

More Kickoff/Coordination Documents

Annotated “Superplot” to Track Conflicts

Underground Systems Coordination

P v. S waste pipe through top of interior footing

P v. E waste pipe through electrical conduit

Challenges: sub participation

maintaining the schedule

existing conditions under slab

Coordinating A/V Equipment

Coordination on Roof

BEFORE AFTER

MEP Coordination Results: Conflicts

Conflict Resolution: ~10,000 “clashes” discovered with NavisWorks

~1000 significant conflicts identified and resolved

76 outstanding conflicts left at time of sign-off (resolved in the field)

“FIRST

PASS”

CLASH

DETECTION

FINAL

SIGN-OFF

UG 73 27 3

L1 <100 48 23

L2 100’s 109 38

RF 100’s 20 12

Trades: HVAC, mechanical piping, electrical, plumbing, fire protection, AV

MEP Coordination Results: RFI’s

MEP Coordination Method Comparison

Method 2-D

“superplot”/informal

3-D

“Clash Detection”

Percent of total

building area

63% 37%

Percent of MEP

systems

~25% ~75%

Density of MEP

systems

1 : 5.1

Field-generated

MEP-related RFI’s

17

12 5

Percent of RFI’s 71% 29%

% RFI’s / % of MEP 2.8 0.39 7 : 1

% RFI’s / Density

MEP

71 5.8 12 : 1

MEP Coordination Results: Change Orders

Change Orders

Scope Entire Building Non-MEP

Systems

MEP

Systems

Original Bid $13.6M $7.94M $5.66M

Change Orders ~$3M ~2.99M* ~$10K

Percent CO’s 22% 38% 0.17%

CO Ratio (Entire Bldg vs. MEP)

125

1

CO Ratio (Non-MEP vs. MEP)

213 1

* Approximately 50% due to owner upgrades, 33% due to unforeseen underground conditions, 17% due to errors in design documentation

Subcontractor Communications

Deck Coordination: PT vs. Penetrations

Deck Coordination: PT vs. Penetrations

Coordination: Slab Edge vs. Embeds

Constructability Review

Layout Drawings for Slab Depressions

Started with finish floor plan view from architect’s model (terrazzo in concrete slab)

Several iterations and markups by field staff based on construction conditions

P.E. dimensioned and noted slab depressions for terrazzo in PT deck

Result: clearly legible, field-specific view of the model for accurate formwork layout

Prefabrication

Exposed stainless

steel ducts through

joists

Clean seams and

high level of finish

required shop

prefabrication

Joists not in A/E

model

Joist Modeling: Custom Revit Families

Standard RVT 24 LH-series

joist

BNB-modeled 24 LH-series

joist

Prefab: More Coordination Required!

Flawless installation of prefab’d stainless ducts

Prefabricated duct in the shop

Conclusions

Only some portions of the project were coordinated with BIM

Due to the unique circumstances of this project related to the

specifications and subcontractors’ capabilities

We have been able to:

Study the dramatic impact of BIM-based coordination of building

systems on the project

Objectively compare its effect on RFI’s and change orders to areas of

the building that were not coordinated with BIM

Demonstrated enough value of BIM for coordination to earn

the trust of the team to pursue other avenues and uses of

BIM for continued benefit of the project

What’s Next

All BIM, all the time

LEGAL

Model-sharing more prevalent in AEC

CULTURAL

“Old school” designers and builders

changing habits, changing careers

REGULATORY

Agency review

PHYSICAL

“Paperless construction” at project sites

trending towards Augmented Reality

OPERATIONAL

“6D” use of BIM to support

facilities operations and maintenance

Questions?

Thank you

Dace.Campbell@BNBuilders.com