Convert SH3D to DWG

A contractor or CAD user may need a Sweet Home 3D floor plan in .dwg to edit it in AutoCAD-compatible software, add construction details, or share it with a consultant. Sweet Home 3D does not export DWG directly, so the conversion requires an intermediate vector or CAD format.

What the SH3D format is

.sh3d is Sweet Home 3D's native project format. It stores a home-design project with walls, rooms, doors, windows, furniture, materials, dimensions, viewpoints, and project settings. Sweet Home 3D desktop editions are available for Windows, macOS, and Linux; the project file is intended to be opened by Sweet Home 3D rather than by general-purpose CAD software.

An SH3D file is not a DWG drawing renamed with another extension. Its objects use Sweet Home 3D's project and interior-design model, so AutoCAD, DraftSight, BricsCAD, and similar applications normally cannot open the file directly.

What the DWG format is

.dwg is the native drawing format associated with AutoCAD and is supported by CAD applications such as DraftSight, BricsCAD, ZWCAD, and others. It can store 2D geometry, 3D entities, layers, blocks, text, dimensions, and drawing metadata for drafting and engineering workflows.

DWG is useful when the recipient must modify a floor plan in CAD software, add annotations or construction details, exchange drawings with consultants, or use a required AutoCAD-compatible file version. Conversion does not preserve Sweet Home 3D's project semantics: a visible wall may become lines or polylines, and furniture does not automatically become editable architectural CAD objects.

How to convert a 2D plan

1. Open the project in Sweet Home 3D and save a backup copy of project.sh3d.
2. Set the plan view before exporting. Hide unnecessary furniture, dimensions, labels, or room fills, and show only the objects needed in the CAD drawing.
3. Choose Plan → Export to SVG format and save floor-plan.svg. SVG is preferable to a screenshot or raster image because it retains vector geometry.
4. Open the SVG in Inkscape, a free desktop vector editor. Inspect the page units and remove decorative elements that should not enter the CAD file.
5. Use File → Save As or File → Save a Copy, select an AutoCAD DXF option such as Desktop Cutting Plotter (AutoCAD DXF R14), and save floor-plan.dxf. The exact option name depends on the Inkscape version.
6. Convert the DXF to DWG with a CAD application such as AutoCAD, DraftSight, BricsCAD, or ZWCAD: open floor-plan.dxf, check the geometry, then use File → Save As and select the DWG version required by the recipient.

A commercial CAD application is not mandatory for the last step. ODA File Converter, published by the Open Design Alliance, can convert between DXF and DWG versions on supported desktop platforms. Open the DXF in a CAD viewer or editor afterward to verify the result; a file conversion alone does not validate scale or geometry.

How to convert a 3D model

Sweet Home 3D can export the model through 3D view → Export to OBJ format. Save the resulting .obj file together with any generated material or texture files. OBJ is a polygon-mesh format, not a CAD drawing format and not an intermediate format that reliably produces native DWG walls, doors, or solids.

Some CAD applications can import OBJ and save the imported mesh in DWG, but the result is usually a faceted mesh or a visual reference. For an editable architectural 3D DWG, use the OBJ as a guide and remodel the structure in a CAD or BIM application. For most floor-plan requirements, the SVG-to-DXF-to-DWG workflow produces more useful output than OBJ.

Online conversion options

General online services normally do not accept .sh3d as an input because they do not understand Sweet Home 3D's project structure. If a service such as CloudConvert or Convertio currently lists both SVG-to-DXF or DXF-to-DWG conversion, it can handle an intermediate file, but it cannot recover SH3D objects, layers, materials, or project settings.

Upload only a prepared SVG or DXF, not the original project, when confidentiality matters. Before using an online converter, confirm the exact input and output extensions, supported DWG release, file-size limits, and deletion policy. Open the returned DWG in CAD software and check units, scale, text, layers, line types, and dimensions.

Quality and compatibility limitations

• The export represents the plan as visible graphics. SH3D metadata, furniture categories, materials, textures, camera settings, and project hierarchy are not preserved.
• SVG-to-DXF conversion may turn text into outlines, substitute fonts, omit fills, alter line types, or place objects on a limited number of layers. Replace important text and dimensions in CAD when necessary.
• Check scale with a known wall length. SVG, DXF, and DWG programs can interpret physical units differently, and a drawing that looks correct may still have the wrong measurement units.
• Inspect arcs, polylines, duplicated lines, hatch boundaries, and closed contours after conversion. These commonly require cleanup before drafting or measurement.
• DWG is version-sensitive. Save the release requested by the recipient because older CAD applications may not open newer DWG versions.