The fastest way to start a takedown is to bring in the plan you already have. StructLoads imports a floor plan from a DXF or a PDF so you can trace the outline and place supports over the real drawing rather than redrawing it. DXF carries true vector geometry; PDF is used as a background to trace. Either way you set the real-world scale first, and this page explains how it works.
Why import instead of redraw
Redrawing a plan from scratch is slow and introduces its own errors. Importing the actual drawing means the geometry matches the design, and you spend your time placing supports rather than reconstructing the outline. That captured geometry then drives the tributary areas and the load takedown, so a faithful import is a faithful takedown. It is the on-ramp to the workflow in how to read a structural floor plan.
DXF versus PDF
The two import in different ways.
| Aspect | DXF | |
|---|---|---|
| Type | CAD vector geometry | Often a flattened drawing |
| Scale | Carried in the file | Set manually from a dimension |
| Best use | You have CAD | A plan is all you have |
| Cleanliness | Layers, true lines | Trace over a background |
A DXF brings in real vector lines, layers and scale, so it imports most cleanly; Autodesk’s DXF reference defines the format as a tagged representation of all the information in a drawing file, which is why entities, layers and coordinates survive the trip intact. A PDF is usually placed as a background image you trace over, setting the scale from a known dimension. Use whichever you have.
Setting the scale
Scale is the one thing you must get right, because every tributary area and load depends on it. Set it from a known real-world dimension on the plan, such as a grid spacing or the overall building width. In StructLoads you tell it the real width the plan represents, and it scales the geometry so the areas and reactions come out in correct units. A wrong scale silently multiplies or divides every load, so confirm it against a dimension you trust.
Placing supports on the plan
Once the plan is in and scaled, you place the supports over it: columns at the grid intersections, walls along the bearing lines, beams between supports. The plan acts as a tracing background, so the supports land in their real positions, and the tributary areas resolve against the imported outline. From there it is the standard free tributary area calculation and takedown.
When import is messy
Import is not always clean. A low-resolution PDF scan, a DXF cluttered with non-structural layers, or a drawing with no clear dimension to scale from all make it harder. There you clean or hide layers, trace selectively, or set the scale carefully from a reliable dimension. A tidy CAD DXF imports best; a scanned PDF needs more care. Either way, the imported geometry is a starting point you confirm, then run the structural load takedown.
Key takeaways: importing a plan
Import a DXF for true vector geometry, or a PDF to trace over as a background, then set the real-world scale from a known dimension and place supports on the plan. The captured geometry drives the tributary areas and the takedown, so a faithful, correctly scaled import matters. StructLoads imports both as a preliminary starting point a qualified engineer confirms.
Quick answers
How do you import a floor plan into StructLoads?
Upload a DXF or PDF in the studio. A DXF brings in true vector geometry, so the outline and lines come in to scale; a PDF is placed as a background image to trace over. You then set the real-world scale from a known dimension, draw or confirm the floor outline, and place columns, walls and beams on the plan.
What is the difference between importing DXF and PDF?
A DXF is a CAD vector format, so it carries the real geometry, layers and scale and imports most cleanly for tracing. A PDF is often a flattened drawing used as a background image; you trace over it and set the scale manually from a known dimension. Use DXF when you have CAD; use PDF when that is all you have.
How do you set the scale of an imported plan?
Set the scale from a known real-world dimension on the plan, such as a grid spacing or an overall width. In StructLoads you tell it the real width the plan represents, and it scales the geometry so tributary areas and loads come out in correct units. Getting the scale right is essential, because every area and load depends on it.
When does plan import not work cleanly?
Import is messier when a PDF is a low-resolution scan, when a DXF has cluttered layers or non-structural linework, or when the drawing has no clear dimension to set the scale. There you may need to clean the layers, trace selectively, or set the scale carefully from a reliable dimension. A clean CAD DXF imports best.