Cut list, takeoff, DXF and IFC

Four outputs, one model

Everything this page shows comes from the same bars as the 3D. No output keeps a number of its own: the cut list is rebuilt every time the sheet opens, the takeoff adds up the bars on the spot, and the DXF and the IFC translate the drawing on the screen.

Each output has a different reader. The cut list belongs to the shop and the installer. The takeoff belongs to whoever buys and prices. The DXF belongs to whoever continues the drawing in CAD. The IFC belongs to whoever coordinates with architecture and services in a BIM program.

That is why each one counts in its own way, and knowing what each one counts is half the job.

• 188 members: in the cut list of the six walls, 524.3 kg, on one A3 sheet
• 539.8 kg: in the takeoff of the same walls, which adds up the bars of each piece
• 1.4 t: in the takeoff after the gable roof (1,368.0 kg)
• 370 pieces: in the IFC 2x3 of the walls, one entity per model bar

The screenshots on this page are from the app, on the roll-formed 9x7 house (FRAMECAD F325iT, C 89x41 of 0.95), first with the walls only and then with the roof.

Who reads each output, and where it lives

The machine file is a different one

The CSV that goes to the roll former, with holes, swages and cutting order, is in Roll-former file. It is not repeated here: the list on this page is for reading, checking and buying, not for the machine.

What no output adds up

Boards (OSB, gypsum, fiber cement), screws, sealing tape and anchors. The takeoff is bar steel only, and the list carries the screw as a spacing note, without a count.

What the standard asks for, and what is practice

No Brazilian LSF standard asks for a cut list, a takeoff or an IFC by that name. What it asks for is the identification of the pieces, the same in every document, and the drawings the job needs. The list and the takeoff are the way to meet that in the factory and in purchasing. Here only the item numbers; read the text in the standard.

Model closed, list first, files last

Every output reads the model as it is when opened. Generating early breaks nothing, but the number changes with every wall and every roof. The order that avoids checking twice:

1. Close walls, openings, bracing and roof

The project cut list counts the walls and the roof. King studs, lattice headers, straps and blocking come in when they are in the model; the floor stays out of the list.

2. Project cut list for the shop

Check each panel by mark and by length. It is the output that counts member by member, including the doubled piece.

3. Takeoff for purchasing

It is the only output that adds up the steel of the whole project, floor included. Export it as CSV and add the cutting waste in the spreadsheet.

4. IFC for coordination, DXF for CAD

The IFC goes to the BIM program of whoever runs the clash check. The sheet DXF goes to whoever continues the drawing; the 3D DXF, to whoever needs the volume in a CAD without IFC.

How much steel the house takes

• 524.3 kg: cut list, walls only
• 539.8 kg: takeoff, walls only
• 1,368.0 kg: takeoff with the roof

The house has 63 m² of plan. The walls come to about 8.6 kg of steel per m² and the project with the roof to about 22 kg/m², without cutting waste.

The project cut list sheet

1. Select a wall and click Project cut list

Any wall will do: the list belongs to the project. The app creates the A3 sheet "Lista de corte da obra" (project cut list) and opens Prints with it.

2. Read panel by panel

Each wall is a panel (V1 to V6), with its total of members and kg in the title. With the roof in the model, the list gains one block per truss type ("TELHADO TL1, TESOURA ...", with chord TB, vertical TM and diagonal TD) and one block of purlins, rafters and bracing, and the top of the sheet reads "6 painéis e o telhado" (6 panels and the roof). If the project runs past one sheet, the list continues on the next, and a second click creates only the sheets that are missing.

3. Export the sheet

The sheet buttons are those of LSF sheets: Export PDF (the browser print) and Export DXF.

Reading a line of the list

Two pieces share a mark when they have the same code, the same section, the same length to the millimeter and the same doubling. That is why V1 has two studs: M1 doubled and M2 single, both 2,800.

The summary by section, checked by hand

The summary adds up the lines of every panel by section, from heaviest to lightest. In the house with the walls only: C 89x41-39x12x0.95, 178 members, 369.1 m, 509.8 kg and RET 50x0.95, 10, 39.0 m, 14.5 kg. The note below warns: these are meters without cutting waste.

Check 1: the studs of Wall 1

Check 2: the kg/m of the C 89x41-39x12x0.95

By the outer developed strip, 89 + 41 + 39 + 2 × 12 = 193 mm; × 0.95 = 183.4 mm²; × 7.85 = 1.44 kg/m. By the centerline, 189.2 mm, 1.41 kg/m; discounting the four bent corners, about 1.39. The catalog uses 1.381 kg/m, less than 1% below the finest calculation. With no weight in the catalog, the app does the outer calculation.

The material takeoff

1. Open the card after the analysis

In LSF, the "Material takeoff" card opens from the diagrams card, which only appears with a result. The sum does not depend on the analysis; the button does.

2. Whole model or selection

"Whole model" adds up every bar; "Selection" adds up only the selected ones, handy for one panel or just the roof.

3. Pick the view

"By profile" and "By cut piece" join collinear bars into one shop piece; "By class" counts the model bar, which is why the track shows up in 217 pieces.

In a stick-built project, a shop piece longer than the configured bar is split into bars for purchasing. In a roll-formed one, the roll former cuts the whole piece from the coil, and the takeoff counts it whole, like the list and the machine file.

Cut piece, roof and CSV

4. Copy or download the CSV

"Copy" puts the table on the clipboard, tab-separated, ready to paste into Excel. "CSV" downloads quantitativo_obra.csv (or quantitativo_selecao.csv), with semicolons and decimal commas, which Excel opens directly when set to a comma-decimal locale.

The list and the takeoff, side by side

DXF: the 2D sheet and the 3D model

These are two different files, in two places. The sheet one carries the sheet drawing; the top one carries the volume of the bars.

Sheet DXF

Click Export DXF. The app converts the sheet as it is on screen, with views, dimensions, schedules and title block, and the .dxf file downloads.

3D DXF from the top

In the Export button at the top, DXF 3D (extruded) translates the meshes of the Structure 3D: every straight bar becomes a solid extruded along its section, and the others become meshes. The file downloads as CalcSteel_Project.dxf and counts toward the plan's export limit.

IFC: the model for BIM

1. Export, Structural IFC

It belongs to the paid plans: for those who do not pay, the line reads "Pro" instead of "IFC 2x3". The app checks the plan, builds the file in the browser and downloads <project>.ifc.

2. Open it in a BIM program

The schema is IFC 2x3, which Revit, Archicad, Tekla, BIMcollab Zoom and BIMvision open. In Revit, through "Open IFC" or linked to the architecture model.

3. Filter by entity and by description

Stud, track, strap, blocking, diagonal, chord, purlin and rafter come out as IfcMember; the column chord, as IfcColumn; the header, as IfcBeam. Each bar carries its label as name (M1042) and its class as description (MNT, GUI, BLQ, CIN): that is how you separate stud from track in the viewer.

What changes the numbers

The numbers of the house, by panel

When the output does not come out, or comes out different

1. "The project has no LSF wall." The project cut list needs at least one wall: roof and floor alone do not open the sheet.
2. folha 1 de 2: crie as outras em "Lista da obra" (sheet 1 of 2: create the others from the project cut list). In red at the top, when the project grew and the list ran past the sheets that exist. Click again: the app creates only the missing ones.
3. There is no takeoff button. In LSF it sits in the diagrams card, which only appears after the analysis. Run the analysis, or use the project cut list until then.
4. IFC needs a paid plan. The menu line reads "Pro", and the app checks the plan before generating. The sheet DXF and the 3D DXF count toward the plan's export limit.
5. Buying from the list left material short. The list covers the walls and the roof: the floor and the cutting waste stay out. Buy from the takeoff of the whole model and add the waste.

One source, four readers

The cut list reads the pieces the same way as the panel elevation: what lies in the plane of the wall, with the piece from another wall shown translucent and left out of its count. The takeoff adds up the bars. The IFC and the 3D DXF translate the drawing. The four outputs are geometry and weight calculations; the strength of each bar is the one the engine verifies in the analysis (Reading the results).

What stays with the designer

1. Cutting waste and buying in bars. No output adds waste; it goes into the CSV spreadsheet, with the bar the supplier sells.
2. The screw count. The list gives the gauge and the spacing by note. The number of screws that item 4.8 f) of NBR 16970-2 asks for is counted in the design.
3. Boards, sealing tape and anchors. They stay out of the takeoff, which is bar steel only, and are taken off from the cladding and foundation designs.
4. The fixing in the BIM model. LSF screws and anchors are not 3D pieces and do not go into the IFC or the 3D DXF. The clash check with architecture and services belongs to whoever coordinates.

The path, in one line

Close walls and roof, generate the Project cut list for the shop, buy from the Material takeoff of the whole model with the waste added in the spreadsheet, and send the IFC to coordination and the DXF to CAD.