Recommended test
Generate the same footprint with two roof systems and compare space, supports and downstream tool compatibility.
- Create a gable roof at a moderate angle with collar-tie framing and a short overhang.
- Inspect the ridge, rafters and tie members from Front and Iso views.
- Save the project, switch to Beam or select a saved Truss definition, then review and build.
- Switch from Gable to Skillion and back, confirming the previous gable structure is restored.
- Compare interior clearance and confirm whether your intended dormer or opening workflow supports the chosen system.
Gable or skillion
Gable roofs expose the broadest Autostrek toolset. Skillion creates a single roof slope and currently does not support Dormer Framer. Choose the roof type before investing in dependent detail.
Select Gable, Skillion or Hip in the roof bar above the preview. Switching away from Gable and back restores its previous structure choice, saved truss and fitting mode. Skillion can use its standard Truss or Rafters option; that choice does not replace the remembered gable setup.
New designs and Default building start with Vented roof, including OSB sheathing, simplified covering, counter battens, tile battens, trim and drainage where supported. Sheathing only removes the covering and batten layers; Framing only also removes sheathing, trim, drainage and soffits. Open the roof’s Advanced settings to customize these layers. Saved designs keep their saved settings.
Single-slope framing
For Skillion, choose Truss for the standard chord-and-post family or Rafters for single-slope rafter framing. Switching roof type into Skillion starts with the standard truss choice; loaded starters and saved designs retain their configured structure.
The current Sauna starter uses Rafters at 8°. Check the rafter dimensions, wall geometry and roof layers after changing the system. Saved gable truss definitions are not used for these skillion choices.
The automatic assembly guide has narrower support: its single-slope adapter handles the standard chord-and-post family, not the new rafter Sauna.
Hip roof V1
The Hip roof option creates four equal-pitch slopes with level eaves. A rectangular footprint has a ridge along its longer side; a square footprint has a central apex. It uses common and jack rafters, four diagonal hip rafters and a ridge board where a ridge exists. Set rafter width, depth and building spacing in Build. This system has its own framing choices and does not use saved trusses, collar-tie or ridge-beam presets.
Hip roof V1 was released on 13 September 2026. See the Hip roof guide for supported dimensions, generation steps, roof layers and live adjustments.
Gable framing options
The Roof Structure menu offers Beam, Collar Tie and Truss. Beam uses a ridge beam and rafters; Collar Tie uses rafters and ties. Truss opens the type-selection dialog, where you can create a project draft or choose a saved definition.
Choose W-frame, A-frame/attic, lattice attic or Mansard, then Manual or the supported preliminary Automatic mode. Planned types remain disabled. The editable building preview supplies span, pitch and overhang, and CC stays fixed. Apply the draft, then generate. Use Edit beside the selected truss or the build review’s Fix link to return to the dialog. See automatic truss sizing.
Beam roofs have a separate Automatic roof dimensions option for supported C24 rafters, a GL30c glulam ridge and integrated ridge supports. This simplified calculation is separate from Code_Aster truss sizing. See ridge beam and rafter sizing.
Mansard and gambrel ends
Choose Mansard through the Gable truss dialog. Gable ends (gambrel) creates two pitches per side with upright ends, and offers preliminary Automatic truss sizing. Hipped ends — full Mansard creates eight roof faces and Manual spatial framing, with a separate read-only 3D analysis. The ordinary Hip button remains the equal-pitch Hip family. See Mansard roof settings and layers.
Angle and overhang
Roof-angle limits depend on the chosen family and calculation mode. The general generator accepts angles up to 65 degrees and overhangs up to 600 mm; preliminary truss checks have narrower bounds. Mansard’s lower pitch is a separate setting. Inspect eaves, ridge height and member intersections after a large change.
New project copies follow the editable building geometry. For a saved source, Advanced settings can explicitly retain the saved dimensions. Existing saved-span locks and legacy fitting choices are preserved for earlier designs. An Automatic result becomes outdated when its geometry or loads change; fitting alone does not approve it. See the visual builder guide for selection and regeneration.
Compatibility comes first
The truss dialog belongs to the Gable roof family; skillion uses separate standard Truss or Rafters choices. Dormer roof openings support conventional rafters and the scoped Manual A-frame path described in gable extensions and A-frame dormer floors. That geometry support does not extend the Automatic calculation to roofs with dormers. Preliminary sizing does not verify complete connections, bracing or Norwegian compliance.
Hip roof V1 requires a positive pitch and a uniform overhang on all four sides. Dormers and Hip-specific assembly-guide generation are outside its scope.