Levels of Development Archives

BIM Levels of Development - Kelar Pacific

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Written by Kelar Pacific

24 October 2017

Construction Design Phases vs BIM Levels of Development – Part 4 of 4

What is considered the industry standard of LODs?

Today, there is no official LOD Standard, or a requirement for one in the U.S. Several organizations are providing LOD Specification Workbooks to help with the adoption effort. These organizations include:

Any given project should follow the standard being used by the client and the designer.

To conclude the 4 part topic of Construction Design Phases vs BIM Levels of Development, confirm the following prior to starting on any project:

Is the project governed by Design Phases or BIM LODs?
If governed by BIM LODs, are the BIM files available for contractor use?
If BIM files are available, be specific about requesting the file types needed.
- Consider Autodesk’s Navisworks as an industry standard for reviewing and extracting quantities and other data. Typically Navisworks file formats (*.nwd) are sufficient.
- The Navisworks Simulate software would likely be the minimum requirement for design simulation and project review.
Is there an LOD Specification Workbook?
- If so, is it available for contractors use?
- Is the contractor bound to the LODs for their cost proposals for each defined portion of work?
Is there a contractual agreement between the Owner/Client and the Architect/Designer that is defined around the LODs the prime contractor, and their subcontractors, may also be bound to?
What is the prime contractor’s cost estimating expectations for each of the various subcontractors? And, will there be different LODs for each trade?
Bottom line, be sure you are clear about how a project is defined and measured for progress and completeness by confirming the use of “Construction Design Phases,” OR “BIM Levels of Development.”

Useful Links for BIM Levels of Development and 5D BIM Cost Estimating:

Ed Wenz

Sage Estimating Consultant

5D BIM Estimating/eTakeoff

Affiliations:

AGC, ASPE, SD Navisworks GC, CM and Specialty Contractor Users Forum

Blog, Education

BIM, Building Information Management, Construction Design Phases, Levels of Development, LOD

Regular Post

Written by Kelar Pacific

17 October 2017

Construction Design Phases vs BIM Levels of Development – Part 3 of 4

What are the Definitions of BIM Levels of Development?

The following reflects the general consensus of the most widely used LOD Definitions:

LOD 100: A Conceptual Model where parameters like area, height, volume, location and orientation are defined.
LOD 200: An Approximate Geometry Model where elements are modeled with approximate quantities, size, shape, location and orientation.*
LOD 300: Precise Geometry Modeling and shop drawings where elements are defined with specific assemblies, precise quantity, size, shape, location and orientation.*
LOD 350: Includes Model Detail and element that represent how building elements interface with various systems and other building elements with graphics and written definitions.
LOD 400: Model elements are modeled as Specific Assemblies with Complete Fabrication, assembly, and detailing information in addition to precise quantity, size, shape, location and orientation.*
LOD 500: As-Built Elements are modeled as constructed assemblies for Maintenance and operations.*

*Can include non- geometric information to the model elements.

How do you use BIM LOD Specification Workbooks?

BIM LOD Specification Workbooks are often required by the client and updated with each revision of a project’s BIM file. If so, it’s important for the prime and subcontractors to base the related progression of their cost estimates and schedules accordingly. The example below is created by the BIM Forum.

The BIM Specification is not a set of requirements as to what is modeled, when, or by whom. Rather it is a language by which users can define these requirements for their own firms or projects. A BIM Specification provides the following benefits:

Helps teams including owners to specify BIM deliverables and get a clear picture of what will be included in a BIM deliverable.
Helps design managers explain to their teams the information and detail that needs to be provided at various points in the design process, and to track progress of their models.
Allows downstream users to rely on specific information in models they receive from others.
Provides a standard that can be referenced by contracts and BIM execution plans.

View or download a copy of the LOD Specification Worksheet:
BIM Forum 2016 Level of Development Specification Workbook (Excel)

We will conclude this 4 part topic on Construction Design Phases vs BIM Levels of Development in Article 4.

Ed Wenz

Sage Estimating Consultant

5D BIM Estimating/eTakeoff

Affiliations:

AGC, ASPE, SD Navisworks GC, CM and Specialty Contractor Users Forum

Blog, Education

BIM, Levels of Development, LOD

Regular Post

Written by Kelar Pacific

10 October 2017

Construction Design Phases vs BIM Levels of Development – Part 2 of 4

It’s important for contractors to understand the various LOD’s for each trade at any point so they can provide related cost and scheduling that is measured by the same design standards being used by the client and the designer. The understanding of how complete a model element is effects not only the Cost Estimates and Schedules, but also Constructability.

LODs – Levels of Development

Definition (BimForum.org) – The Level of Development (LOD) Specification is a reference that enables practitioners in the AEC Industry to specify and articulate with a high level of clarity, the content and reliability of Building Information Models (BIMs) at various stages in the design and construction process.

Level of Development vs. Level of Detail

LOD is sometimes interpreted as Level of Detail rather than Level of Development. There are important differences:

Level of Detail is essentially how much detail is included in the model element.
Level of Development is the degree to which the element’s geometry and attached information has been thought through – the degree to which project team members may rely on the information when using the model.
In essence, Level of Detail can be thought of as input to the element, while Level of Development is reliable output.

Does the project contractor utilize the designer’s LODs or Design Phases?

The LODs are not defined by design phases. Rather, design phase completion, as well as any other milestone or deliverable, can be defined through the LOD language. There are several important reasons for this approach:

There is currently no detailed standard for the design phases.
Building systems progress from concept to precise at different rates, so at any given time different elements will be at different points along this progression.
Design Phases are often utilized by the Prime Contractor as “Design Milestones.” These Milestones are utilized by the contractor’s estimators and schedulers. Their subcontractors should use LODs specific to their trade.