Component Links
Reference for the Component Links panel: link table, automatic surface connection (auto-connect), highlighting modes and splitting connections
Overview
Interior components (interior walls, floor slabs between storeys) transfer heat between two zones. To do so, the two adjoining surfaces of the neighbouring rooms must be connected as side A and side B within a shared component link (component instance). The Component Links panel lists all these surface-to-surface connections, checks their validity, highlights them in the scene and, with the auto-connect feature, provides an automatic function that intersects the building geometry and creates connections.
Opening the panel
Activate the Building mode in the mode toolbar, then select the Component Links page in the property area. The scene switches to a special highlighting mode for connected surfaces.
Link table
The table shows all component links in which both sides reference a surface, with the columns:
| Column | Content |
|---|---|
 /  | Status icon: connection valid / faulty (details in the tooltip) |
| CI-ID | ID of the component link |
| Surface side A | Name of the surface on side A |
| Surface side B | Name of the surface on side B |
| Component | Assigned construction (--- if none) |
The following errors are detected and marked with a stop icon and red text in the affected surface column:
- a surface is already referenced by another component link,
- side A or B is missing a valid boundary condition,
- the boundary condition of one side is linked to a constant/schedule zone (not permitted for interior components),
- both sides reference the same surface.
Selecting table rows exclusively selects the associated surfaces in the 3D scene — this allows every connection to be checked visually.
Highlighting in the scene
Use Display mode: to choose how connected surfaces are shown:
- Transparent surfaces — the building is drawn transparently; red connection boxes are displayed between connected surface pairs.
- Randomly coloured surfaces — each connected surface pair receives a shared random colour; switching again re-rolls new colours.
Auto-connect
Auto-connect automatically intersects the building geometry (surfaces are split at contact areas) and creates component links between opposing surfaces, so that one-dimensional heat exchange can be modelled.
Start auto-connect — performs the intersection directly with the current settings. The entire project is always processed, surface links are created and existing components are not replaced. The result is applied as an undoable project change.
Open settings… — opens the Auto-connect settings dialog with all options and a log.
”Auto-connect settings” dialog
Project options:
- Connect entire project (all buildings and geometries)
- Connect only selected and visible geometry
Settings:
- Maximum distance: [m] — maximum distance between two surfaces up to which a connection is created (permitted 0–10000 m, default 0.5 m).
- Maximum permissible threshold angle: [deg] — maximum angular deviation of the surface normals (permitted 0–45°, default 5°).
- Create surface links — controls whether component links are created in addition to the intersection.
- Replace all interior components with default components (see below) — replaces the constructions of all processed components with the constructions stored in the Default components area: connected interior components receive, depending on their inclination, the construction for Interior wall: or Ceiling:, single-sided components the one for Exterior wall:, Roof: or Floor:. Components without a construction receive these defaults even when the option is disabled. The preset comes from the project’s default constructions; use the … buttons to select other constructions from the database.
The Log tab shows the run with warnings (yellow) and errors (red) as well as a summary statistic (processed/intersected surfaces, created connections and component links). Start auto-connect runs the process within the dialog; only Apply to project transfers the result into the project, Cancel discards it.
Automatic boundary condition assignment
After each auto-connect run, missing boundary conditions are automatically supplemented from the project’s default boundary conditions: components connected on both sides receive the interior boundary condition on both sides. For single-sided components, the free side is determined by the usage type of the construction — exterior wall/roof receive the exterior boundary condition, ground-coupled types the ground boundary condition, interior wall/ceiling/basement ceiling are set adiabatic. Existing boundary conditions are retained (except for the adiabatically enforced interior types).
Good to know:
Run auto-connect as soon as the shell geometry is in place — before the detailed construction and boundary condition assignment. The intersection splits surfaces at contact areas; subsequent geometry changes may therefore require new runs. After each run, check the log for warnings and the link table for red entries.
Splitting a connection
The Remove button splits the connections selected in the table: each affected component link is turned into two separate, single-sided links (one per surface) with otherwise unchanged properties. The action is undoable (“Surface-surface connection removed”).
Manually connecting an interior wall between two surfaces
Individual surface pairs can be connected without intersection using the Link… button in the Assign Constructions panel: select exactly two surfaces of different rooms, choose a construction — the surfaces are merged into a shared component link.