Goal:

Constructability Review


Phase(s):

Post-conceptual and schematic design, during design development, pre-construction documents and entire construction phase

Objective(s):

[_] Analyze the design and examine different "means and methods" for construction
[_] Review and check buildability: code compliance, value engineering, schedule and quality
[_] Logistical planning for construction of the building

Description:

Constructability review is a valuable BIM use to review the building model and check for coordination, buildability and bidability. It can be used to enhance existing systems related to construction sequence, equipment access, completed work and assembling difficult components. This can provide additional links between site and design to collaboratively solve constructability problems that may arise during construction.

Constructability can be defined as a review of the building model along with plans and specification to determine constructability of the project and coordinate with other project participants. In this process the building design and buildability is being discussed, different options are considered, design is finalized and communicated to other parties involved (Sanvido, 1990). After have been briefed about project information, context, program and design, the consultants and specialists review the constructability of the design, offer their feedback and suggest changes that would improve the overall design and "means and methods" (Eastman et al., 2007).

Modeling the building in 3D would point to any of the missing information in building certain building components or systems, and the sequence of assembling the components can be easily determined. In this way all the misunderstandings can be cleared out before the construction starts, since all the important design details were clarified. If a particular part of the building has a constructability problem, valuable would be even just to model that part in more detail then to have the whole building fully detailed (Ganah et al., 2005).


Constructability problems are usually caused by insufficient information on building components and their assembly provided to the project team by the designer or misinterpreted design intent and could be avoided by the proper and organized collaboration between design and construction team using modern visualization and communication tools (Ganah et al., 2005).


Potential Benefits:

  • Contractors can analyze the design and test various "means and methods"
  • Ensure design can be built to meet targeted cost and schedule
  • Expose errors and omissions in design documentation (model)
  • Recommend alternate solutions while keeping design intent
  • Use model to stage deliveries to the project
  • Other potential benefits may include: initial cost estimation, review of layouts, material selection, value engineering

  • Contractors get introduced to the design early in the process, are able to investigate various "means and methods" of construction and give their input on constructability of the project
  • Early contractors input ensure the project’s targeted budget and schedule can be met ensuring effective team collaboration
  • Constructability review can reveal potential errors and omissions in design documents
  • Alternate solutions can be suggested considering material selection and value engineering keeping the initial design intent but staying under the budget and on schedule
  • Design visualization aids in understanding the project much better and in more detail, and forces the project team to think about the process differently
  • Analyze various construction methods and techniques finding potential opportunities to increase efficiency while keeping design intent intact
  • Communicate the latest design revisions while construction was in progress and increasing safety by reducing rework on the project
  • Get feedback from subcontractors on their scope of work, constructability and placement of sleeves, embeds and blockouts

Experienced Setbacks:

  • Convincing consultants and fabricators to come on board with BIM
  • Incorporating specifications in the model

Levels of Detail Considerations:

  • Provide appropriate project information regarding the design, its use and context to the specialists to review, and gain feedback/ advice/ changes
  • Means and methods of construction
  • Model of temporary facilities and equipment
  • Cost and time information
  • Construction sequence animation
  • May include simulations, studies, reviews and checks
  • Encourage selective modeling since constantly battling with the model sizes and how to break the model down which makes it difficult to document


Team Competencies Required:

  • Experience in construction
  • Knowledge of various "means and methods" of construction
  • Detailed understanding of cost analysis and impact of various "means and methods"
  • Good communication skills and ability to collaborate with various specialists and across disciplines
  • Performing various studies, reviews and simulations during the course of developing the design and checking it for constructability issues
  • Being technologically savvy, have people skills and being interested in engaging others in BIM work


Characteristics in order to substantiate BIM use:

  • Project - Complex or repetitive form, materials or sequence, projects requiring a lot of equipment
  • Organization - BIM software and IT available
  • Environment - Highly collaborative
  • Contract - Have modifications in the Means and Methods clause
  • Process - Design Build and Integrated Project Delivery

Potential Modeling Methods:

Building Information Model in software that provides following information:
  • 3D coordination model, and also 3D CAD model, 3D sketching, VR virtual reality, VRML model for easy manipulation
  • 3D animation for assembling the components, rendered image for visualizing materials and their appearance or any other visualization depending on the project and what information needs to be presented (Ganah et al., 2005)
  • Cost and business information of building materials, elements and process
  • Time and sequence
  • Animation of sequence and construction methods
  • Sustainability information
  • Temporary facilities
  • Equipment

Potential Outputs:

  • Constructability review as a BIM use can greatly enhance the ability of contractors to get involved in the process early on and provide feedback.
  • Can help track various information on the project: 3D model, method, time, cost as well as green building and sustainability information.

Legal / Commitment Considerations:

  • Professional liability issues
  • Keep in mind that designer in traditional project delivery Design-Bid-Build is usually protected under professional liability insurance with the “Means and Methods” clause:
“The Design Professional shall not have control over or charge of and shall not be responsible for construction means, methods, techniques, sequences or procedures, or for safety precautions and programs in connection with the Work, since these are solely the Contractor's responsibility under the Contract for Construction.The Design Professional shall not be responsible for the Contractor's schedules or failure to carry out the Work in accordance with the Contract Documents. The Design Professional shall not have control over or charge of acts or omissions of the Contractor, Subcontractors, or their agents or employees, or of any other persons performing portions of the Work." (reference missing)
  • Integrated contractual relationships like design build or IPD integrated project delivery are highly recommended for successful BIM constructability use

Additional Resources:

General Description:

  • Eastman, C. M., P. Teicholz, et al. (2008). BIM Handbook: A Guide to Building Information Modeling for Owners, Managers, Architects, Engineers, Contractors, and Fabricators, Hoboken, NJ: John Wiley and Sons
  • Ganah, A. A., Bouchlaghen, N.B. & C.J. Anumba (2005). VISCON: Computer Visualization Support for Constructability. ITCON
  • Campbell, Dace A., M. A. Mortensen Company, Building Information Modeling The Web Application for AEC, April 2007
  • Interview with: Jonathan Mallie, SHOP Construction, New York (October 3, 2008)
  • Interview with: Marilia Rodriguez, KTA, Philadelphia (October 9, 2008)

Quantitative Studies:

Not available

Case Study Examples:

GM Flint, Michigan - Ghafari Associates (Eastman et al., 2008) website
San Francisco federal Buildling - Morphosis
Benjamin D. Hall Interdisciplinary Research Building, University of Washington
FIT A-Lab, New York, SHOP Construction

Software Applications:

NavisWorks
Bentley Navigator, Bentley Triforma
Revit Architecture
VICO Constructor
Autodesk Design Review
DProfiler - preliminary cost estimate
Digital Project CATIA
Tekla XSteel