BIMtopia
Module 8 - Design Project Brief: System Design — Structural Framing Systems
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Module 8 - Design Project Brief: System Design — Structural Framing Systems

Focus

The focus of this stage in your integrated design project is to explore how you can best implement the strategies that you identified for achieving your project goals as you design the features of your building’s structural system.  For this check-in you’ll add these features to your building model:

  • Grids
  • Structural Framing Elements
    • Structural Floors
    • Beams & Beam Systems
    • Structural Columns
    • Structural Walls
    • Foundations

Recommended Approach

At this point in our design process, we’ll continue adding the details to flesh out our initial building design ideas -- for this check-in, focusing on the materials, member sizes, and layout of the structural framing system.

Start with a Strategy

Before you dive into building modeling in Revit, start by carefully considering your overall structural system strategy:

  • What structural material makes sense for the local conditions (availability and familiarity) as well as your project design goals -- for example, buildability (what material will be most cost- and time-effective) and sustainability (which has the best carbon footprint)?
  • Would you like the structural system to be hidden from users of the building or an exciting design feature that’s part of the user experience?
  • Should the structural framing be visible from the exterior? Visible on the interior? Or hidden in the walls and ceiling?
  • Does your building form have an overall geometry that will help dictate the best grid layout?
  • Will specific areas of your building benefit from different structural strategies? For example, can you use a very typical, closely-spaced column scheme in the office areas? Would a wide-open, few column, long span truss scheme work better for an atrium or exhibition space?

Create a Linked Structural Model

  • Create a new Revit model using the Structural Template.
  • Link your architectural model to this new structural model using origin-to-origin positioning.
  • Use the Copy/Monitoring tool to copy these elements from your architectural model:
    • Levels -- to create matching levels with the same floor-to-floor heights in your structural model.
    • Floors -- to create matching structural floor elements in your structural model.
  • Create Grids in your structural model to organize the placement of your structural framing elements.
    • For steel, concrete, and heavy timber structures, Structural Columns are typically placed at Grid intersections.
    • For light-frame wood structures, Grids are typically placed at the Core Face: Exterior of exterior walls and interior structural walls.
  • With those elements in place, you’re ready to start placing your structural framing elements.

Place Structural Framing Elements Precisely

  • Use your Grids to align your structural framing elements:
    • Structural Columns (centerlines or faces)
    • Structural Walls
  • Locate the tops of Beams and Beam Systems relative to the floors they support:
    • Cast-in-place concrete beams are typically placed with their tops at the level of the floors they support.
    • Steel beams are typically placed with their tops at the bottom of the floors they support. So, remember to lower them by the thickness of the floor assembly.
    • Wood beams can go either way (it’s your design decision) -- embedded in the floor or placed below the floor.

What Size Should the Framing Elements Be?

With experience, you’ll develop an intuition for the approximate size of the framing elements based on the sizes you’ve seen in other buildings with similar conditions.  So, as you get started, the member sizing is a bit of an educated guess.  A good strategy is to make your initial sizes large enough to accommodate the largest potential size that the analysis might dictate. That way, resizing the elements to make them smaller where possible will be less impactful.

Does the Structural System affect Other Systems?

The design of your structural system will have a big effect on the design work that will be required for HVAC systems in an upcoming module.  The layout and depth of the beams and beam systems often dictate the space and paths available for routing ductwork for your HVAC system.

Typically -- the longer the spans, the deeper the beams.  And the deeper the beams, the tighter the space available for ductwork in the ceiling.

How Detailed Should This Version of Model Be?

At this stage, you’ll want your structural model to accurately reflect the locations of the major framing elements and essential components of your structural strategy -- the beams and beam systems, the structural walls, any trusses or long-span elements.

For the scope of this course and design project, you won’t be able to resolve all the framing details to handle every case throughout your building’s geometry -- and that’s okay!  Our goal is to understand the big structural design decisions and their impact on other building systems.  There will be lots of unknowns and issues for future resolution -- that’s typical, expected and okay!

Thinking Ahead

In the weeks ahead, we’ll continue to develop the details of this initial building model as you design each of the major building systems.  If it helps your creative process, you can start thinking ahead to:

HVAC Systems (Module 9)

  • Designing the heating, cooling, and ventilation systems to provide the fresh air required and handle the heating and cooling loads predicted for your building.
    • Where can you use passive heating or cooling through the building envelope?
    • Where will active heating and cooling systems be required?
    • How will your Structural System choices and framing member sizes affect your options for placing the HVAC System elements?

Progress Check-In / Documenting Your Design Journey

About Design Journal Entries

You’ll be sharing your ongoing design process and progress with others in our class community through a posting in an online Design Journal using Notion.

Feel free to use whatever format best captures the ideas that you want to share -- text, images, sketches, photos of hand sketches, intermediate models, results of analyses, and so on.

For this class, your design process is as important as the final result.

Post a Design Journal Entry

Create a new posting sharing your Design Journal entry on this linked Notion page:

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Design Project Check-In: Structural Framing Systems

Your Design Journal entries this week should highlight your design thinking that influenced your decisions about:

  • your overall strategy and the features of the structural system
  • the material and framing system selected
  • the locations of structural columns and major framing elements
  • any special structural challenges

Model Coordination

Upload the latest versions of your architectural and structural models to Autodesk Construction Cloud, then copy these latest versions into your Model Coordination space to explore the integrated design.

  • Walk through a merged model view to experience how the architectural, structural, and HVAC designs work together.
  • Look for any potential conflicts or issues that require resolution.

Weekly Design Project Check-In

You’ll sign up for an appointment next week with a member of the teaching team to review your progress and share tips about how to proceed.