Soffits

Available in the Build generator for gable and skillion roofs.

Skillion roofs

Choose Skillion → Roof Structure → Rafters or Truss. Open the roof’s Advanced settings → Soffits and enable the existing soffit checkbox. Four panels follow the roof slope directly beneath the overhang framing:

• The high/front run spans the full width between the side edge boards.
• Each side run butts into the front run and reaches the low-end fascia.
• The low/back run fits between the side runs.

Corners use straight butt joints, without diagonal mitres. Panel thickness is measured perpendicular to the roof. Front/back board lines follow the long walls; side board lines follow the slope. Thickness, board count, visual gap width and the plain-panel option use the same settings as gable soffits. The model contains four solid panels; gap markings are not physical ventilation openings.

Fascia boards and an overhang with space outside the finished wall are required. Rafters uses the existing perimeter outriggers; Truss uses its top-chord tails at the front/back and outriggers at the sides. Both use the same panel layout, so neither mode has separate eave support dimensions or gable-end siding closure control. Zero-degree roofs also work. At steep pitches or with thicker panels, the fascia extends downward only as needed to meet the soffit underside; its top edge stays in place. Enabling soffits does not change the fixed 48 × 98 mm Truss chord profile.

The four Soffit Single-slope parts appear in Roof → Soffits and retain their geometry, IDs, board lines and material through .strek save/reopen. Regenerate an existing building to add them.

Gable roofs

In Build → Roof, enable Soffits. This single checkbox adds four sloping gable panels, two horizontal eave panels and one eave support beside each rafter or truss top-chord tail. All panel and support settings appear beneath it. The gable panels attach beneath the actual outriggers, meet at the ridge and finish against the fascia. Their exposed width fits between the finished gable wall and the inside of the bargeboard. This option is available for gable roofs and is off by default, including for older presets. It requires equal wall heights and works with collar ties, a ridge beam, and saved A-frame or W-frame trusses. W-frame builds now generate gable outriggers as part of their roof framing, whether or not soffits are enabled. Fascia boards and a positive overhang are required for the complete soffit assembly. Earlier local presets with either soffit option enabled now enable the complete assembly; turning Soffits off disables all panels and supports for the next generation.

Set Panel thickness (default 16 mm), then enable Show board gaps to illustrate boards running along the roof slope at the gables and along the walls at the eaves. Thickness, board count and gap width apply to both types of panel. Boards per panel counts boards: three boards have two internal gaps. Gap width sets the actual model-space width of each dark marking. There are no extra gaps at the two outer edges. Board cover width is (panel width − (board count − 1) × gap width) ÷ board count. For example, 400 mm with three boards and two 5 mm gaps gives 130 mm per board.

The form shows separate approximate gable and eave cover widths before generation. Final panel dimensions and board widths follow the generated wall finish and roof supports. Invalid combinations with no room for boards prevent generation. Turning the markings off gives a smooth panel. The markings remain visual: the model contains six solid panels, not individual boards, physical ventilation openings, or ventilation sizing.

Find Roof → Soffits (6) below Bargeboards and Eave Soffit Supports. Each panel is named by gable/slope or eave side and retains its part ID, length, width, thickness, material, area, support IDs and board/gap settings. Markings move and hide with the panel and do not produce separate parts or timeline steps. Save the .strek project to retain the geometry and metadata; save a build preset to reuse the generator settings.

Gable roof eave panels and supports

The Soffits option includes two horizontal eave panels, named Soffit Eave Front and Soffit Eave Back, plus their support boards. Each panel runs along the wall, meets the inner ends of the gable panels, and spans from wall sheathing or framing to the fascia’s inside face. The top touches the support undersides; the bottom sits 3 mm above the standard 19 × 123 mm fascia bottom. The panels remain single parts regardless of board count, with gap markings on their underside.

The default board size is 22 × 98 mm, with editable thickness and height. Each board runs perpendicular to the wall, starting at the outer face of the wall sheathing, or at the studs/top plates when there is no sheathing. Wall siding and battens do not change this starting face. Its outer end meets the fascia’s inside face; its bottom starts 19 mm above the fascia bottom with the default 16 mm panel thickness. Changing panel thickness adjusts this clearance when generating, keeping the panel underside 3 mm above the standard fascia bottom.

The supports appear under Roof → Eave Soffit Supports, immediately above Soffits, with names such as Eave Soffit Support Front 01 and Back 01. Select an individual board and use the vertical Move axis to adjust its height. Each support keeps its own ID, dimensions and material and is counted separately in the cutlist and timeline. Its wall, fascia and rafter references are stored as metadata; moving a support does not move the panels or neighboring supports. Save the project to retain manual adjustments. Generating a new building recreates the supports at their initial alignment.

Flush wall dormer openings

Placing a Flush Wall dormer trims the horizontal soffit panel and its gap markings at the same opening boundaries as the fascia. Support boards that intersect the opening are removed from the model and part list. The retained panel sections keep their existing name, ID, material and Soffits group; their remaining area and section lengths are recorded. The opposite eave and gable soffits stay intact. Regular and closed-eave dormers keep their soffits.

For a Flush Wall building extension, the soffit ends instead meet the extension’s two outer side-wall faces. Siding is included when present; otherwise the ends meet the outer available wall layer (battens, sheathing or bare framing). The soffit continues beneath the extension’s roof overhang up to the wall, rather than stopping at the fascia junction. Supports intersecting the extension’s wall span are removed. Corner trim does not move the continuous wall stopping plane.

Save/reopen retains these cuts. For a dormer placed before this refinement, regenerate the building and place the dormer again to apply the cleanup.

Gable dormers and building extensions

New gable roof dormers and building extensions automatically receive soffits when the main building has soffit panels. There is no separate dormer switch. Each gets two sloping panels at its single gable end, two horizontal eave panels, and individual support boards beside the rafters that reach the eaves. Short rear rafters above the main roof do not create floating supports.

Panel thickness, boards per panel, gap width, support dimensions and materials come from the main roof’s existing parts. The board cover width is recalculated for the dormer’s actual overhang. Gable panels fit beneath the outriggers and meet at the ridge. Eave panels sit 3 mm above the standard fascia bottom, below their supports, and start at the side-wall sheathing or framing.

Ordinary dormer eaves are beveled against the main roof surface. Extension eaves continue back to the host wall. At extension corners, the new panels and main roof panels meet on diagonal joints, so they do not overlap; the visual board gaps and any main-roof supports within the corner are trimmed to the same joints.

Panels are named Dormer/Extension Soffit Gable Left/Right and Dormer/Extension Soffit Eave Left/Right. Supports are individually numbered. They remain part of the dormer assembly, use the existing Soffits and Eave Soffit Supports roof categories, and carry their IDs, dimensions, material and panel area into the cutlist and saved project. Gap markings remain part of each panel.

This applies when creating a dormer; existing placed dormers are not rebuilt automatically. Regenerate and place them again to add the new parts. Shed roofs remain unchanged.

The main roof’s Close eave ends with siding option is inherited too. With simplified front-wall siding, the existing gable profile extends into both small soffit-end openings. Each eave panel retracts by the actual siding thickness at its front end only (19 mm for 19 mm siding); its rear roof/wall joint is preserved. The closures keep the siding’s ID, material, wood grain and board-pattern alignment. Panel measurements, area and gap markings follow the shorter eaves. There is no additional dormer control. With the main option off, the front siding stays unchanged.

Closing the eave ends with siding

With Soffits enabled and simplified wall siding selected, enable Close eave ends with siding. This optional setting extends the existing gable siding profiles into the four openings between the sloping gable soffits and horizontal eave panels. The closures follow the actual soffit surfaces and fascia limits. Their colour, wood grain and board pattern continue from the main siding.

Each horizontal eave panel retracts by the actual siding thickness at both ends, stopping against the siding’s inside face. With 19 mm siding, this shortens each eave panel by 38 mm overall. The model, gap markings, dimensions, area and cutlist measurements use that shorter length. The support boards stay in place. The reported wall footprint continues to measure the wall body, excluding these small roof-end extensions. Automatic downpipe placement also follows the original wall profile and corner boards, so closing the soffit ends does not push the downpipes away from the wall. Manual downpipe offsets remain available.

The closures belong to the existing wall siding parts and keep their IDs; they do not add separate objects to the Soffits group. Saving a project preserves the extended geometry, siding pattern alignment and eave recess measurements. Save a build preset to reuse the option. It is off by default and only takes effect for gable roofs with enabled soffits and simplified siding; other siding modes and disabled soffits retain their normal profiles on the next generation.

Opening Framer preserves these stepped profiles when cutting doors and windows, including garage walls with siding only and no sheathing. The small upper covers stay in place without extending siding down beneath the soffits. Removing an opening and rebuilding the wall also retains the profiles. Intact panels generated before this correction can recover their outline from the mesh when an opening is added. For a wall already distorted by an earlier opening cut, remove and recreate that opening; regenerate the building if the distorted wall was saved without its opening-step history.