Off side fabrication and modular construction is not new but, the way it is been done nowadays has a quantitative and qualitative impact. Reducing time and cost has been more achievable because of it.

1. Evaluate Applications of
Off-Site Fabrication
Sunny Mahajan
CE 501
Individual Tool Assignment

2. Definition
• CII defines" Prefabrication is a manufacturing process,
generally taking at a specialized facility, in which various
materials are joined to form a component part of the
installation"
• In other words simplest form of prefabrication is
building brick used throughout the world.

3. Classification
• Non-Volumetric Off-site fabrication - Small parts of
building components to construct the main parts of
building components. Such as wall partitions, pipe work,
structural steel parts, etc.
• Volumetric Off-site fabrication - Units comprising usable
space. Such as toilet units, plant rooms, lifts etc.
• Modular Buildings - Most units are substantially
complete in themselves. Such as retail unit, houses,
temporary units, medium rise office etc.

4. Present Usage & Potential
Residential Commercial Heavy Civil
Modular
Volumetric
Non- Volumetric
Industrial
(Types of Construction)
(TypesofOff-sitefabrication)
Present
Potential

5. Process
Prefabrication and
preassembly
Building Construction
and installation
Site PreparationEngineeringDesign

6. Standardization
Cartoon by Mr. Buckminster Fuller.

7. History
Hong Kong Banking Corporation Headquarter
Renkioi Hospital
The Dymaxion House

8. Re-emergence
• With the technological advances in fields such as BIM, IT,
CAD and computing, Off-site fabrication is more effective
and feasible.

9. Recent Trends
• Prefabrication using BIM has been very successful as it
has removed all past fallacies in prefabrication
construction.
• Advances in computing has enabled to facilitate decision
making for prefabrication. Using graph theory and IFC
Database different feasible configuration can be
computed.
• New market are evolving for exporting volumetric
modularization units. Which can cater increased return
on investments for existing manufacturing industries.

12. Parameters
• Time
• Productivity
• Cost
• Waste
• Quality
• Safety

13. Few aspects of Cost
Additional Cost Savings Cost
Crane (Capacity) Productivity (Cutting learning Curve)
Fabrication facility On-site cost saving shorter construction period
Transportation Less on site work
Fewer construction workers
Less Transportation (Materials)
Efficient use of Crane
Unplanned on-site remedial works
Changes to project cash flow

14. Mc Graw Hill Construction - Smart Market Report on
' Prefabrication & Modularization' which conducted
a internet survey of hundreds of AEC professionals.
This study indicates that :-
a. 66% report that project schedules are
decreased. 36% by four week or more.
b. 65% report that project budgets are decreased.
41% by 6% or more.
c. 77% report that construction waste is decreased.
44% by 5% or more.

15. Limitations
• Labor Union
• Transportation

16. Evaluate Applications of Off-site
fabrication (Highways)
• Considering Highway Industry and 5DPM, off-site
fabrication can help Quality control, minimal public
disruption and environmental impact.
• Off-site fabrication can help manage cost, schedule
and quality complexity which may be a solution for
context/shareholders constraints.
Cost Schedule FinancingTechnical Context
Reference - Shane, J., Strong, K., and Gransberg, K. (2012). “Guidebook: Project Management
Strategies for Complex Projects”, SHRP2 and Transportation Research Board.

17. Example - T 30 Hotel Tower
No. Items B2B Traditional buildings
(including 5-star hotel)
1 Construction waste 25t About 3000t
2 Construction dust No Yes
3 Construction ignition work (welding & gas cutting) No Yes
4 Construction water consumption No About 5000t
5 Wall & Ceiling decoration No plaster Plaster
6 Steel consumption 68 kg/m2 Reinforced concrete:
about 75kg/m2 Steel
structure: about 140kg/m2
7 Concrete consumption 100 kg/m2 About 1000 kg/m2
8 Construction site material delivery 150 vehicles About 1000 vehicles
9 Construction scaffold No Yes
10 Top sealing & Elevation 15 days About 1 year
11 Interior decoration 1 month About 1 year
Note: The foundation is not included. Designed by construction design institute per BSB
parameters & local geological features, BSB foundation is similar to that of conventional
buildings, only that it can be reduced due to lighter building weight.

18. References
• Shane, J., Strong, K., and Gransberg, K. (2012). “Guidebook: Project Management Strategies
for Complex Projects”, SHRP2 and Transportation Research Board.
• Broad Sustainable Building Co. Ltd. “T 30 Tower Hotel : Technical Briefing”.
• Eastman C., and Sacks R. "Relative Productivity in the AEC Industries in the United States for
on-site and off-site activities". Journal of Construction Engineering and Management, ASCE,
July 2008.
• Tam V.W.Y., Tam C.M., Zeng S.X., and Ng. W.C.Y. "Towards adoption of Prefabrication in
Construction". Journal of Building and Environment, Science Direct, October 2006.
• Haas C.T., O'Connor J.T., Tucker R.L., Eickman J.A., and Fagerlund W.R. Report on
"Prefabrication & Preassembly Trends & Effects on the Construction Workforce" for Center
for Construction Industry Studies. The University of Texas at Austin, May 2000.
• Gibb Alistair G.F. " Off-site Fabrication: Prefabrication, Pre-assembly and Modularisation"
John Wiley & Sons, 1999.
• Mc Graw Hill Construction - Smart Market. "Report on Prefabrication & Modularization:
Increasing Productivity in the Construction Industry “. 2011.