measuring the impact of bim in...
TRANSCRIPT
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
Registered Provider with The American Institute of Architects
Continuing Education Systems. Credit earned on completion of
this program will be reported to CES Records for AIA members.
Certificates of Completion are available on request.
This program is registered with the AIA/CES for continuing
professional education. As such it does not include content that
may be deemed or construed to be an approval or endorsement
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
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
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
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
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
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