Assign Constructions

Overview

In the Constructions panel you link the surfaces of the building model with constructions (component assemblies) from the database. Each assignment creates or modifies a component link (component instance), which connects one or two surfaces with a construction and its boundary conditions. The 3D scene colours the surfaces either according to the construction colour or as a U-value false-colour display.

Opening the panel

In the vertical mode toolbar next to the 3D scene, activate the Building mode and select the Constructions page in the property area (group of envelope-surface pages). When the page is activated, the scene automatically switches to the corresponding colouring mode.

Colouring: constructions or U-values

Use the radio buttons behind Colouring: to choose the display:

• Constructions — each surface receives the colour of its construction stored in the database. Surfaces without a component link or with a missing/invalid construction are shown in dark grey (#404040).
• U-values — false-colour display of the thermal transmittance using the Turbo colour scale. A continuous colour legend titled U-value [W/m²K] appears at the edge of the scene; the scale limits are determined from the U-values that actually occur and rounded to 0.5 steps.

The U-value is calculated in a simplified way from the material layers of the construction:

$$U = \frac{1}{R_{si} + \sum_j \dfrac{d_j}{\lambda_j} + R_{se}}$$

with the fixed surface heat transfer resistances $R_{si} = 0{.}13$ m²K/W (interior) and $R_{se} = 0{.}04$ m²K/W (exterior), the layer thicknesses $d_j$ in [m] and the thermal conductivities $\lambda_j$ in [W/mK]. Constructions with a missing material or invalid parameters receive no U-value and remain grey.

Legend table

The table lists all constructions of the currently visible surfaces with a colour field and name (column Construction). In U-value mode the column U-value [W/m²K] is added (3 decimal places, --- for values that cannot be calculated). In addition, two collective rows may appear:

• Unused surfaces (not connected/assigned) — visible surfaces without a component link.
• Surfaces without or with an undefined/invalid construction — surfaces with a component link but without a (valid) construction.

A double-click on a row with a valid construction opens it directly in the construction database dialog.

Editing, replacing, selecting

Below the table, three buttons act on the highlighted table row:

• Edit… — opens the construction in the database dialog (see Materials & Constructions). Only active for rows with a valid construction.
• Replace… — on all visible surfaces, replaces the assignment to the highlighted construction with another construction chosen in the database dialog that opens afterwards. For the collective row without a construction, a construction is instead assigned to the affected surfaces for the first time.
• Select — selects all surfaces of the highlighted row in the scene, including for the collective rows (e.g. all surfaces without a construction).

During replacement, surface heating assignments of a component link are removed if the link has no active layer (see Assign Surface Heating).

Assigning a construction (group “Selected surface(s)”)

The Selected surface(s) group is only active when at least one surface is selected in the scene. The Selected construction: field shows the construction of the selection — for a non-uniform selection e.g. “3 different constructions”, for a missing assignment “None”. Behind Assign construction: three ways are available:

• DB… — opens the construction database dialog for selection; the chosen construction is assigned to all selected surfaces. Surfaces without a component link automatically receive a new link with the project’s default boundary conditions (interior/exterior side).
• Table — assigns the construction currently highlighted in the legend table without a dialog.
• Link… — creates an interior-wall link between exactly two selected surfaces (only active in that case). Existing single-sided links of both surfaces are merged into a shared component link; if boundary conditions are missing, a new link is created with the default “interior” boundary condition on both sides. If both surfaces belong to the same room, the action is aborted with the message “Both surfaces belong to the same room.”

All assignments are undoable.

Related topics

• Boundary Conditions
• Component Links
• Construction Check
• Materials & Constructions (database)