Model Establishment Framework

BIMFix Framework for Shared Model Establishment

For Building Lead Consultants using Autodesk® Revit®

This free downloadable framework is a document which can be referenced from or attached to a BIM Execution Plan (BEP). The Framework provides the Project Team clear methodologies on how to establish and share Project BIM (Building Information Modeling) Models, where the lead design consultant is using Autodesk® Revit® as their primary authoring application. The framework is designed to be flexible in meeting project needs, work across BIM/CAD software platforms, and for actions to be controlled and traceable.

Suggested Project BEP wording to reference this document:
This project will engage the BIMFix Framework for Shared Model Establishment, V1.0 - September 2016, freely downloadable from the website: http://bimfix.blogspot.com.au/p/framework.html.  In the event of a conflict between the BIM Execution Plan (BEP) and the BIMFix Framework for Shared Model Establishment document, the BEP will take precedence.

Downloads:

All Versions of the Framework will remain on the BIMFix Site.

BIMFix Framework for Shared Model Establishment, V1.0 - September 2016

Accompanying Download Tools – Zip download here.

        This includes:

• Revit^® Detail Component Site Map Grid Template
• Revit^® 3D Map Grid
• AutoCAD^® Translocation script

Public Comment:
Six months after the release we are looking to improve the document, and expands its Building lead design role beyond Autodesk Revit. We are seeking the following public input in one or both of the following:

1. Expressions of interest from Building Design Leads to create similar parallel frameworks for:

• a. Bentley AECOsim Building Designer,
• b. Graphisoft ArchiCAD,
• c. Trimble Tekla Structures, and
• d. Vectorworks

2. Detailed review and comment on the current Framework document V1.0

Please download the framework above. BIMFix email contact details can be found via the Contact Tab.  Interested participants should contact the BIMFix blog.

How the Framework addresses the Ten Objectives of Model Origin and Setup.

This Framework has been specifically designed to address the ten objectives set out in the former BIMFix article: Considerations of BIM/Model Setup. Below is an explanation of how these are achieved.

1. Limited survey data available at early project design stage

It is unlikely a current land survey will be available on the first day of design and modeling. Process P1. allows for this shortcoming. If necessary a temporary site can be generated from available data (e.g. Google Maps or similar), which can include a proposed datum level.

Some design firms have access to Government Cadastral CAD maps. If not, at the time of engagement of the Land Surveyor or Civil Engineer, a Cadastral map may be provided. The Cadastral map can be used as an initial basis, including establishing a local site origin as in Process P2.

2. Universal Geodetic coordinate systems

All the processes cater for Geodetic World Coordinates for the region. Process P1 & P2 will enable content to report relevant Eastings, Northings and height Datum’s, as well as export and in most circumstances using the appropriate units.

3. Limitations of computer computation algorithms and units

All the below processes will work off the strict premise. Project Participants authoring in:

Project Participants working in Revit® will primarily be dealing with a building or structure and will be working directly to local origins, using the Shared Positioning tools to report Geodetic World Coordinates. Revit® can be engaged to cover items outside the building scope, but it is not the core function of the product, and consideration of another design tool may be more appropriate.

4. Different project team member needs

The processes in the Framework enables a solution allowing disciplines to work to their preferred Units.

5. Different BIM deliverable needs

When looking at the available BIM goals, many project team members will require a different approach to model coordinates and origins. Some examples;

Campus Master Planning: If the Architect is engaging Revit® for Campus Master Planning, all modeling should occur in a single site model. Typically for Campus Master planning, only simple building massing is required. If other consultants are also involved at this stage; the project shall be set up appropriately to report Geodetic World Coordinates. See Process P2 and P1. Keeping backgrounds simple can suffice to meet the deliverable output.

Clash Detection: The clash detection rules and data available in Building models compared to Site in-ground services are very different. It is also common for the Architect to lead the Building Coordination, with the Civil team leading the Site in-ground services coordination. 

To ensure building relocations don’t adversely delay Building coordination, it is best to export the building files from the building (Revit® Project Origin) consistent building relative origin. This will also improve performance and easier orthogonal orientation in the clash detection software application. This local building origin is also beneficial when working with some shop drawing/fabrication tools, as many don’t work well with Geodetic world coordinates.

6. Scalable within projects sizes

The established processes work for all project sizes. Some of the processes can be over the top for small projects, but all the principles still apply.

7. Building relocation management

Process P3 and P5 directly address this task within Revit®. As all building files are lined origin to origin, building relocations have a greater impact on site works rather than building works. An updated AutoCAD Site files should be released to all non-Revit® project participants, following a building relocation.

8. Allocation of responsibility and risk mitigation

The Project Setup processes define a clear line of responsibilities, tasks, and checks. The processes are designed to specifically highlight human errors to all the project participants and enable quick rectification.

9. Allowance for human error, and follow-up resolution

The framework is also set-up to enable errors to be picked up quickly and early. In the event the Revit® Shared Coordinate processes fail for some reason, as the building files shall be linked origin to origin, it minimizes downtime.

10. Work within international standards

This framework works within the following standards/specifications and application guides:

AEC (UK) BIM Protocol For Autodesk® Revit® v2.0 - Sections 6.3.1, 7.4

AEC (UK) BIM Technology Protocol For ARCHICAD v2.0 - Section 7.4

BS 1192:2007+A2:2016 Collaborative production of architectural, engineering and construction information - Section A2 & A3.
Building Information Management - A Standard Framework and Guide to BS 1192 - Mervyn Richards - 2010 
- Section: 6.2 Origin and orientation.

BIMForum Level of Development Specification 2018 - Draft for Public Comment - 5.1 Clearly Define the Local X,Y,Z Origin: Basis for all LOD.
BuildingSmart Australasia - Initiative - Model Setup IDM - 2018.

New Zealand BIM Handbook - Appendix A - Modelling and documentation practice - Section 4.3 – July 2014