What is the SH3D file format?
The .sh3d format is used by Sweet Home 3D, a free interior design application developed by eTeks. These files hold complete home projects created with the application, storing data such as floor plans, placed furniture objects, and both 2D and 3D views of the design.
Internally, an .sh3d file is a ZIP archive - renaming it to .zip lets any archive tool inspect its contents. It bundles a Home.xml document (introduced in Sweet Home 3D 5.3) describing the home layout in XML, along with embedded 3D furniture models in OBJ format, JPEG textures, and a ContentDigests file holding SHA-1 hashes for integrity checks. Older files carry a Java-serialized Home entry instead of (or alongside) the XML descriptor.
Each .sh3d project stores the full state of the design and can be modified freely by users who open it in Sweet Home 3D. Related Sweet Home 3D library formats share the same ZIP-based structure but serve different purposes:
.sh3f- furniture library.sh3t- texture library.sh3l- 3D plan and lights library.sh3p- plug-in package
Security & safety
RISK: LOWAn .sh3d is a data project (ZIP of plan + models), not an executable, so opening one in Sweet Home 3D is low risk. Get the app only from the official sweethome3d.com (or trusted repositories/Flatpak) - third-party 'SH3D viewer' downloads are unnecessary and may be PUP/ adware, since the real app is free. The rename-to-zip trick lets you inspect contents safely.
Format details
in a nutshellFULL NAMESweet Home 3D design fileaka Sweet Home 3D home file, SweetHome3D project file
DEVELOPEReTeks (Emmanuel Puybaret)since 2006 (Sweet Home 3D 1.0)
CATEGORY3D Image Files
MIME TYPEapplication/octet-stream
TYPEZIP-based interior design project (home model + furniture + textures)
STANDARDOpen · royalty-free
MAGIC BYTES · FILE SIGNATURE
OFFSET
00010203
HEX
504B0304
ASCII
PK··
An .sh3d file is a ZIP archive, so it begins with the standard ZIP signature 50 4B 03 04 ("PK"). It is identified not by a unique magic number but by the internal entries - a 'Home' (Java-serialized) and, since v5.3, a 'Home.xml' describing the home.
Programs that open SH3D files
Windows3 apps
Sweet Home 3D
Open-source Install and File > Open the .sh3d; it loads the 2D plan and live 3D view. The only full-featured reader/editor. 
7-Zip
Open-source Open the .sh3d as a ZIP archive to inspect/extract Home.xml and embedded models - does not render the design. 
Sweet Home 3D Online
Free Use the browser/Java Web Start editor to open and edit the home without installing the desktop app. 
macOS1 app
Sweet Home 3D
Open-source Open the .sh3d in the macOS build to view and edit the home (Intel and Apple silicon). 
Linux1 app
Web1 app
Technical details
deep spec| Container format | ZIP archive; magic bytes 50 4B 03 04 ("PK") at offset 0, identical to a standard ZIP file |
| Primary home descriptor | Home.xml - an XML file introduced in Sweet Home 3D 5.3 (2017) that describes walls, rooms, furniture, labels, cameras and floor levels |
| Legacy home descriptor | Java-serialized Home object (binary); the sole descriptor in pre-5.3 files, retained alongside Home.xml in 5.3+ for backward compatibility |
| Compression | DEFLATE per-entry ZIP compression; 3D models and textures are frequently stored uncompressed (ZIP STORED method) for direct access by the application |
| Embedded 3D models | Furniture geometry stored as OBJ/MTL files inside the archive, referenced by Home.xml or the serialized Home entry |
| Texture encoding | JPEG images for furniture surfaces, wall, floor and ceiling textures - embedded directly as numbered entries in the ZIP |
| Integrity mechanism | ContentDigests ZIP entry holding SHA-1 hashes of embedded images and models; each ZIP entry also carries a CRC-32 checksum |
| MIME type | application/x-sweethome3d (application-specific); generic fallback is application/octet-stream |
| XML schema | Home.xml conforms to SweetHome3D.dtd; elements include <home>, <room>, <wall>, <pieceOfFurniture>, <camera> and <level> |
| File inspection | Renaming .sh3d to .zip allows any ZIP-compatible archive manager to open and extract Home.xml, 3D models and textures without Sweet Home 3D |
| Internal versioning | Since v5.3, Home.xml is the authoritative descriptor; the serialized Home binary is preserved for applications older than 5.3 |
| Typical file size | A few hundred KB to tens of MB, scaling with the number of embedded furniture models and texture images |
| Platform support | Windows, macOS and Linux via the Java desktop application; browser-based editing via Sweet Home 3D Online |
| Related sibling formats | .sh3f (furniture library), .sh3t (texture library), .sh3l (3D plan and lights library), .sh3p (plug-in), .sh3x (online editor home) - all share the same ZIP-based container |
| Released | 2006 (Sweet Home 3D 1.0) |
| Latest version | XML Home.xml entry added in Sweet Home 3D 5.3 (2017); current app series 7.x |
| Open standard | Yes · royalty-free |
| Specification | www.sweethome3d.com |
SH3D conversions
Possible
.SH3D .3DSGUIDE
There is no direct SH3D-to-3DS converter; export the 3D scene to OBJ from Sweet Home 3D, then convert the OBJ…
How to convert
.SH3D .JPGGUIDE
Yes, you can get a JPG from an SH3D file by rendering a photo directly inside Sweet Home 3D (free).
How to convert
.SH3D .OBJGUIDE
Yes - open the file in Sweet Home 3D (free) and use the built-in OBJ export from the 3D view.
How to convert
.SH3D .PDFGUIDE
Yes, SH3D converts to PDF - open the file in Sweet Home 3D (free) and use File > Print to PDF to export the…
How to convert
.SH3D .SVGGUIDE
Yes - open the file in Sweet Home 3D (free) and use Plan > Export to SVG format.
How to convert
Not possible
Community Q&A
asked by usersNo questions yet - be the first to ask about SH3D files.
Frequently asked questions
How do I open an .sh3d file?
Install Sweet Home 3D (free, Windows/macOS/Linux, from sweethome3d.com) and use File > Open. There is also a free online editor. It's effectively the only software that reads the format.
Can I open an .sh3d without installing Sweet Home 3D?
Use the free Sweet Home 3D Online editor in a browser. To merely inspect the contents, rename the file to .zip and open it with 7-Zip - but you can't view the design that way.
How do I share a Sweet Home 3D design with someone who doesn't have the app?
Export from Sweet Home 3D: the floor plan to PDF or SVG, the 3D scene to an OBJ model, or a rendered photo (PNG/JPEG). Those open anywhere.
How do I get the 3D model out of an .sh3d (e.g. into Blender)?
Open it in Sweet Home 3D and use the 3D view's 'Export to OBJ format'. Import the resulting OBJ (with its MTL and textures) into Blender, MeshLab, etc.
What's the difference between .sh3d, .sh3f and .sh3t?
.sh3d is your saved home/project. .sh3f is a furniture library and .sh3t a textures library - add-on catalogs you import into the app, not designs themselves.
Is an .sh3d the same as a ZIP file?
Yes - it's a ZIP archive containing Home.xml (or a legacy serialized Home) plus 3D models and textures. Renaming to .zip lets archive tools open it, but only Sweet Home 3D can render the design.
References
1Wikipedia - Sweet Home 3Den.wikipedia.org
2Just Solve the File Format Problem - SH3Djustsolve.archiveteam.org
