CMD Group is a ConstructConnect® company. Learn more

Minimizing the Size of Family Files (Revit Objects)

12/10/2008 by Dennis Neeley


The power of BIM is pronominal. Stretch the side of the building and walls, floors, roof, ceilings and all the related drawings change, take a door out of any view and it leaves your project and disappears from every view where the door could be seen. Check for conflicts and the software tells you where pipes are hitting structural members. Owners are seeing reduced overall project costs (pay the architects and engineers more and save 10 to 20 times that amount in reduced construction costs). Architects and engineers worry less about errors and omissions in their drawings and schedules. The number of AEC professionals using BIM is increasing, the number of projects being created in BIM is increasing, and everything is perfect. Oh, except that the project files are getting to big and computers are grinding to a halt.

We create Revit Family Files and System Families (Reed SmartBIM Objects). Object file size is one of our most important concerns. We work to create the best objects possible, time is not the essence in our work, quality is. But even when the focus is on quality it is not always clear how an object should be created, should we create hundreds of small file size objects (that most likely do not cover all the options) or one larger parametric object that can be adjusted easily to be millions of objects. Will the design professional rather spend time looking through hundreds of objects and then insert a small file size and when the object needs to change need to search again, or would they rather put in one larger file that is parametric so when the object needs to change they can make the change in seconds.

Another question is do you create all 3D objects, or do we need to also create 2D objects. It seems logical that a 2D toilet object is smaller than a 3D toilet object (it is) and there is really no reason to have hundreds of 3D toilets in the high rise building project. On the other hand you may want a 3D toilet object for design and presentations. 3D toilet objects are bigger than 2D toilet objects because of the sculptural nature of the object. What about non sculptural objects. A couple of months ago we got a complaint that our casegoods file sizes were to big and we should offer 2D cabinet drawings. The complaint was based upon the misconception that if the user created a kitchen layout for an apartment building and it added 3.812 MB’s to the project and they had one-hundred units it would add 381 MB’s to the project. He had not tested this so I showed him that Revit does not work the way he assumed, duplicating the cabinet layout 100 times resulted in an increase in project file size from 3.812 MB to 6.628MB, and adding 500 of the kitchens increased the project to 17.836 MB. Once he understood this his concerns went away.

The next section will point out another misconception, that 2D objects are smaller than 3D objects.

Recently we took on a project for a manufacturer that resulted in a detailed investigation of object design and file size. The manufacturer had a specific project for an architectural firm working on a hospital project. There were several floors of patient rooms, nurse stations and work rooms that needed casegoods inserted that needed to show up in both plan and on interior elevations. Understandably the architects wanted the smallest files possible.

With Revit there are three options for the creation of an object

1. Models with solid surfaces – This is the modeling approach you are most likely familiar with. The models look like solid objects, surfaces can have colors and textures assigned. The objects show up in plan, elevation, sections, and in 3D. When taken to a rendering program the objects can look photorealistic

2. 3D model lines – This approach uses single lines in 3D. The result looks like a wire frame model. When inserted in a Revit project the object will show up in plans, elevations, sections and in 3D, in all cases as a wire frame. The objects will not render as photorealistic objects in renderings. Intuitively you would imagine that the file size of a similar object would be smaller than approach #1 above.

3. 2D lines – 2D model lines are drawn on a surface, so if you draw them on the floor surface they will show up when you are looking at a floor plan, but because they have no 3D component nothing will show up in elevation and they are not a 3D object so in renderings they do not show up. Intuition would say that this approach would result in the smallest addition to the architect’s drawings, although you will need both 2D plan and 2D elevations that must be inserted into the drawings.

We undertook a study to confirm the assumptions; the results may not be what you would guess.

The 2D line object and the Model Line object look the same in plan. The 2D object is 236kb. The Model Line object is 200kb.

In elevation both objects look correct.

In the perspective view the 2D line object is not visible. Note that the Model Line object does not hide the wall and floor lines beyond the object.

Reed has modeled scores of 3D casegoods objects; they range from 500 to 600 kb.

At this point we had eliminated the 2D line object. It was bigger than the Model Line object and did not show up in perspective. We still needed to make a decision on 3D objects or Model Line objects.

The next study was to put the objects in a Revit project and then study what happens to file size when multiple copies are inserted.

We created a wall section, when saved the file size was 556kb.

Adding one Model Line object resulted in a file size of 648kb. Inserting 32 Model Line objects did not increase the file size, still 648kb Inserting 320 objects takes the file size up to 680kb.

Clearly inserting multiple copies of an object has very little effect upon the Revit project file size.

We then conducted a similar experiment with a 3D object.

A 3D object with wall created a file size of 1092kb. Inserting 10 objects results in no file size increase, 1092kb. Inserting 100 objects into the file has an insignificant increase, 1100kb.


The result of this investigation was that the best solution was to create the objects as 3D objects. Although the 3D object is a bigger file size the difference is insignificant to the project and the 3D SmartBIM Objects have advantages in visualization and reuse of the objects. Revit is very efficient in the management of these objects so adding multiple copies of the SmartBIM Objects was insignificant. Also the 3D SmartBIM Objects we created also rendered nicely.

When creating Revit objects it is important to consider static and parametric objects, in most cases Reed creates parametric objects as we believe that the increased file size is more than offset by the functionality of easily modifying the Smart BIM Objects. It is also important to experiment to make sure your assumptions about initial file size and how the object will affect the project when copied multiple times is accurate.

I have mentioned in other articles that I am seeing the same issues that we encountered with CAD coming to light with BIM. In the 80’s computers were quickly over powered by CAD drawing operations. For us that were writing software for CAD we were constantly refining our software to avoid bringing the computers to a standstill. Now we have computers that are thousands of times more powerful, this has allowed BIM to work, but once again it would certainly be nice next year if the computers were thousands of times more powerful than today’s models.

Recent Comments

I know that we live in the electronic (supposedly paperless) age, but occasionally it is helpful to have a hard copy of these electronic articles. Is BIM Smart enough to make available a print version of all of these informative articles? Thank you for your consideration. JLH
John Hoffmann -
Dec 11 9:29 AM
With all your testing, have you also evaluated performance as well as file size? Our internal testing verifies your information about size but this is only part of the issue. When you use 3D content with shapes and extrusions that display in all views, the size is less important than the performance hit. We have found that whenever Revit must calculate view depth and cut planes for modeled elements to insure correct display that the performance when going from view to view is compromised. Also, we have found that very small but complex families, particularly with array formaulas, may not compromise model size but most definitely compromise performance. Family size is only part of the issue. In our larger projects, it is less important than performance and family function.
Phyllis Robbins -
Dec 15 1:26 PM
Nice article. Although not the intention of the article, it would seem that you would also need to factor in the time it takes to create 3D parametric objects vs. any of the others. Depending on the object and how you want to have it flex, one could easily get more time involved in fighting with the way Revit thinks than it might be worth (depending on the situation).
Justin Martin -
Mar 09 1:32 PM

Article Archive

Date Article
11/17/14 Top 10 largest construction project starts in the U.S. - October 2014
11/14/14 Non-residential Construction Starts Rose Gently in October
07/10/14 The Importance of Matching Volume to Contractor Capacity in JOC Procurement Strategy
07/10/14 Consider a Seed Project as Part of Your JOC Procurement Strategy
07/10/14 The Best Unit Price Book for Your Job Order Contract
07/02/14 ECONOMIC NUGGETS – July 1, 2014
10/23/14 Twenty major upcoming Water Treatment Plants and Manufacturing & Warehousing construction projects - U.S. - October 2014
10/23/14 Twenty major upcoming Alberta and British Columbia construction projects - Canada - October 2014
10/15/14 Trend lines of construction starts in Canada - September 2014
10/15/14 Top 10 largest construction project starts in Canada - September 2014
09/17/14 Twenty major upcoming midwest and northwest construction projects - U.S. - September 2014
09/17/14 Twenty major upcoming medical and educational construction projects - Canada - September 2014
09/17/14 Trend lines of construction starts in Canada - August 2014
09/17/14 Top 10 largest construction project starts in Canada - August 2014
08/15/14 Twenty major upcoming medical and educational construction projects - U.S. - August 2014
08/15/14 Twenty major upcoming industrial and water treatment construction projects - Canada - July 2014
08/15/14 Trend lines of construction starts in Canada - July 2014
08/15/14 Top 10 largest construction project starts in Canada - July 2014
07/24/14 Twenty major upcoming entertainment facility and stadium/arena construction projects - U.S. - July 2014
07/24/14 Twenty major upcoming Ontario and Quebec construction projects - Canada - July 2014
07/24/14 Trend lines of construction starts in Canada - June 2014
07/24/14 Top 10 largest construction project starts in Canada - June 2014
07/14/14 Top 10 largest construction project starts in the U.S. - June 2014
02/03/14 Infographic: Where Can You Use Project Leads in the Construction Process?
07/25/13 The Canadian Economy’s Two Great Blessings
02/15/13 Construction Economic Notes – February, 2013
11/05/12 Recycled-Content Tile
10/05/12 Fiber-Cement Siding
09/18/12 Return on Your Green Home Improvement Investment
08/09/12 Green Building Solutions to Stormwater Runoff
08/07/12 An “Aha” Moment Solves Challenge of Cost Estimating Local Circus Roof
07/19/12 Estimate Types
06/20/12 Ground-Source Heat Pump
05/14/12 Universal Design for Outdoor Living
04/23/12 What Is Universal Design?
04/09/12 Natural Landscaping
03/14/12 Green Material Alternatives for Plumbing Fixtures
03/02/12 Budgeting & Financing Green Construction
02/22/12 Greening Your Firm
02/10/12 Roofing Defects
02/06/12 Roofs: energy efficiency strategies
01/18/12 Commercial Real Estate and Green Construction
12/14/11 Renewable Energy & Distributed Generation Technologies
11/04/11 Tubular Skylights
10/04/11 Are Online Ads An Endangered Species?
09/27/11 Performance Bonds Guarantee Clients Receive Exceptional Service
09/15/11 Deconstruction for Green and Economic Benefit
09/01/11 4 Ways for Businesses to Create a Good First Impression on Twitter
08/11/11 Building Information Modeling (BIM) for Green Building
07/21/11 Green Alternatives for Concrete
07/12/11 Evaluating Products Over Their Life Cycle
06/30/11 Low-Cost Green Strategies
06/28/11 Bricks are from Venus, Clicks are from Mars
06/17/11 Zombie Avoidance Techniques for Building Product Manufacturers
06/08/11 Blogs & Websites: The 5 Signs of Website Wellness
06/06/11 Building Product Manufacturers & Green Products
06/01/11 Is Fear of Sharing Information Costing Your Company Sales?
05/26/11 What Are Green Products?
05/20/11 The Building Envelope
05/16/11 Blogging: Website Heal Thyself
05/03/11 Metals Compared to Wood for Sustainable Construction
04/12/11 Storm Water Collection & Infiltration
03/23/11 Commissioning the Green Building
02/23/11 Building Program for Green Design
01/21/11 Building Deconstruction Process
05/02/11 Why Building Product Manufacturers and Social Media Are a Marriage Made in Heaven
05/06/11 Building Product Manufacturers: How Understanding Architects Can Help Your Business
10/21/09 Distributors & Manufacturer Representatives
07/15/10 Estimating Doors: Tips from the Experts
07/06/10 How to Handle Construction Materials to Prevent Mold
06/21/10 How to Maximize the Benefits of Exterior Security Lighting
06/04/10 SmartBuilding Index
06/01/10 Regional Housing Construction Tracking and Forecast Information
05/28/10 How to Find Regional Construction Tracking and Forecast Information
05/24/10 Building Product Manufacturers
05/18/10 Practicing the Art of Sustainability - Why Atlanta's Current Building Codes Need Updating Now
02/23/10 Learning to use EE
01/11/10 Earn AIA CEU Credit Attending RCD Webcasts
07/17/09 Cost Estimators Winning Work With BIM
07/16/09 Becoming an Invited Bidder - More Tips
07/16/09 Becoming an Invited Bidder - Tips
07/16/09 Becoming an Invited Bidder
07/16/09 SmartBIM Object Modeling Guidelines for Revit
07/15/09 Interference Check and BIM
06/26/09 A Look at Contractor Failure: Part 2
06/19/09 RicciGreene Associates
06/19/09 Doug Thornton AIA, LEED A.P. of AERC, PLLC
06/18/09 A Look at Contractor Failure: Part 1
06/12/09 Owners and SmartBIM Objects – What You Need To Do
06/10/09 Dealing with the IRS
06/05/09 Getting Paid on Construction Contracts
06/02/09 BIM Coordination and Collaboration
05/28/09 Marketing Your Construction Firm on the Cheap
05/20/09 Little Habits with Big Payoffs for Contractors
05/12/09 SmartBIM Spaces
05/07/09 AIA Show Recap as Seen by the SmartBIM Solutions Team
04/27/09 Business Case Study - Survey Of Spending Patterns In Educational Facilities
04/23/09 Taking Advantage of the Recession: Hiring the Right People
04/20/09 Cork as a Green Flooring Option
04/08/09 Owners - It's Time to Substantially Increase Your Architect's and Engineer's Fees
03/05/09 There's a Solution to Performing Time Consuming Quantity Take-Offs
02/20/09 SmartBIM Library is Half-Off for a Limited Time Only
02/09/09 You are Wasting Your Money
01/20/09 Obama: 'Dramatic Action' On Economy Needed
01/14/09 Use of BIM Jumps Dramatically Over Last 12 Months
12/10/08 Minimizing the Size of Family Files (Revit Objects)
11/11/08 Maximize Online Advertising Dollars
11/07/08 Architects and Engineers, WE NEED YOU
10/29/08 Why Do You Need SmartBIM Objects
10/28/08 Why Building Information Modeling?
10/29/08 10 Questions To Ask About BIM Objects
10/08/08 The Object Mess
10/07/08 Implementing BIM to Your Office
10/06/08 Meeting the Needs for Governmental BIM Compliance while Avoiding Current Liability Obstacles
09/15/08 The BIM Transformation is Manageable with the NEW SmartBIM Library v3
09/14/08 KOLBE Windows and Doors vs. Building Information Modeling
09/12/08 The Evolution of Building Information Modeling: BIM 1-2-3
08/11/08 BIM 101 Overview - From Hand Drawings, CAD and now BIM
08/12/08 Draper, Inc. on BIM Object Developments
07/08/08 IFD Library Partners work to establish standards for creators of BIM software
06/23/08 Architectural Education
06/17/08 Parametric Revit Objects – Part I - Fundamentals
06/17/08 Window Glazing Coefficients
06/01/08 Frequently Asked Questions About Building Codes
06/05/08 Calling All Current and Prospective Revit Users - This Blog Is For You
05/06/08 System Requirements for SmartBIM Library
05/06/08 SmartBIM Library 2.0 Release Notes
05/05/08 Building Information Modeling Moves into AEC Mainstream, Adding Value to Project Delivery Process
04/08/08 Flooring: Cost Considerations
02/08/10 General Contractors & Trade Contractors
01/24/08 Building Element Models (BEM)
12/21/07 LEED Certification Primer
12/13/07 Building Integrated Photovoltaics (BIPV)
09/24/07 Mixed-mode Building Design Combines Old and New Ideas
10/15/07 Checklists Identify Potential Envelope Design Improvements
10/24/07 Greenroofs as High Performance Design
10/21/07 What Makes a Building Product Green
10/24/07 Lighting Considerations in Green Building
10/24/07 Water Conservation in Green Buildings
10/24/07 Rainwater Collection Systems
10/24/07 Efficient Cooling Methods for Green Buildings
10/24/07 Controlling Heat Transfer in Green Buildings
10/24/07 Limiting Heat Loss Through Windows
10/23/07 Formaldehyde Use in Building Construction
10/23/07 Using Plants to Improve Indoor Air Quality
11/05/07 Greening Healthcare
10/19/07 Daylighting Controls
10/19/07 Use of Windows, Skylights and Light Pipes in Daylighting
10/19/07 An Overview of Daylighting
10/19/07 An Overview of Solar Ventilation Air Heating
10/19/07 Types of Collectors for Solar Water Heating
10/19/07 An Overview of Solar Water Heating
10/19/07 Cooling Load Advoidance
10/19/07 Components of Passive Solar Heating Designs
10/19/07 An Overview of Passive Solar Heating
10/23/07 Improving Indoor Air Quality
10/19/07 An Overview of The LEED Rating System
10/19/07 Cost Considerations in Building Deconstruction
10/17/07 Building Deconstruction
10/25/07 Roofing Considerations in Green Building
10/19/07 Green Site Selection and Development
10/24/07 Reducing Energy Use in Buildings
10/17/07 Green Demolition
10/18/07 Integrating Solar Power Generation into Buildings using Thin Film PV
09/10/07 Compost Company Promotes Green Environment
03/31/06 Green Roof Sets An Example For Minneapolis Sustainable Design

CMD Group- construction industry news-imageā€ title=