Windows, Glazing & Shading
Reference of the window databases: glazing systems with angle-dependent SHGC curve, windows with frame, and shading elements per DIN EN ISO 52022-1
Overview
Three databases describe the transparent building components: glazing systems define the U-value and solar energy transmittance (SHGC) of the glazing, windows combine a glazing system with a frame, and shading elements describe adjustable shading via their radiation-physics properties. Windows are assigned to sub-surfaces via window components, see Window Components; the control of shading is described in Shading.
Glazing systems
Access via Databases > Window glazings… (dialog “Window glazing system database”).
Properties
| Field | Unit | Meaning |
|---|---|---|
| Type | - | model type; available is Simple (simplified model with flat-rate values) |
| U-value | W/m²K | thermal transmittance of the glazing, must be > 0 |
| SHGC, normal incidence | - | total solar energy transmittance g at 0° angle of incidence (0…1) |
| SHGC, hemispherical | - | total solar energy transmittance for diffuse radiation (0…1) |
Angle-dependent SHGC curve
The group SHGC (angle-dependent) contains a value table (columns Angle [degrees] and SHGC [---]) and a chart of the profile over the angle of incidence 0-90°. When the value SHGC, normal incidence is changed, VICUS Buildings scales the entire curve proportionally to the new 0° value.
- Create standard SHGC curve generates a typical curve in 10° steps with the relative support values 1 / 1 / 1 / 1 / 0.98 / 0.94 / 0.86 / 0.69 / 0.37 / 0 (0° to 90°), scaled with the nominal value 0.75 (typical double glazing). If an element lacks a valid curve, this standard curve is created automatically.
- Import from clipboard takes a two-column number table (angle, SHGC) without a header row, columns separated by spaces or tabs; decimal commas are accepted. Conditions: first row 0°, last row 90°, at least two rows, SHGC values between 0 and 1 - otherwise an error message appears (“SHGC data cannot be pasted”).
Windows
Access via Databases > Windows… (dialog “Windows database”).
Glazing system
In the group Glazing system, the glazing system is chosen from the database; the U-value, SHGC and the angle-dependent curve of the selected system are shown for reference.
Frame
The group Frame describes the frame fraction of the window via the field Frame type (selection list with English labels):
| Frame type | Inputs |
|---|---|
None | no frame - the window consists entirely of glazing |
Simple | Frame fraction in % of the window area and U-value of the frame in W/m²K (must be > 0) |
Complex | Frame fraction in %, Material from the material database and Thickness of the material in m |
The frame fraction reduces the effective glazing area; the heat losses of the frame enter the balance with the specified U-value or the material properties, see Window Calculation Model.
Shading elements
Access via Databases > Shading… (dialog “Shading database”). The built-in database contains 24 shading profiles with properties per DIN/TS 18599-2:2025-10 (tables 9-11), e.g. “External blind white, 10° position” or “Roller shutter white, closed”.
Properties (group “Shading Device Properties”)
| Field | Meaning |
|---|---|
| Installation type | External (outside, in front of the glazing), Internal (inside, behind the glazing), BetweenPanes (in the gap between panes) |
| Solar transmittance τe,B | solar transmittance of the shading device (0…1) |
| Solar reflectance ρe,B | solar reflectance of the shading device (0…1) |
| Solar absorptance αe,B | absorptance, automatically calculated as (display only) |
The sum of τ and ρ must not exceed 1, otherwise the element is invalid.
Venetian blind in 45° slat position
The option Venetian Blind in 45° Slat Position converts the entered datasheet values (closed position) per DIN EN ISO 52022-1, equations (1) and (2), to the 45° slat position:
The option must not be enabled for built-in profiles that already carry “45° position” in their name - their values already include the correction.
Reference g-value
The group Reference g-value shows the total solar energy transmittance gtot of the combination of the shading device and a fixed reference glazing (g = 0.60, Ug = 1.1 W/m²K), calculated per DIN EN ISO 52022-1, section 6.4.2 (simplified method with the heat transfer values G1 = 5, G2 = 10, G3 = 30, G4 = 3 W/m²K depending on installation type). The value serves solely to compare shading elements with one another - in the simulation the reduction factor is calculated for each window individually from its own glazing.
If the inputs leave the application limits of the simplified method (τe,B 0…0.5; ρe,B 0.1…0.8; g of the glazing 0.15…0.85; Ug 0…6 W/m²K), gtot is still calculated, but marked in color and provided with a warning.
Good to know:
For product data from manufacturer documentation, the two values τe,B and ρe,B from the datasheet (usually given for the closed position) are sufficient. Then compare the displayed gtot with the manufacturer’s value for the reference glazing g = 0.6 / Ug = 1.1 W/m²K - if the two roughly match, the properties have been entered plausibly.