Reference measurements, calculation cases and reporting for frames, glazing edges, installation details and whole windows.
On this page
Choose a starting point
Library… chooses and places geometry. Window Analysis… reviews its assessment and reference measurements. Bridge Analysis… sets up general linear and point bridges. These controls sit together above the layer table in the KOALA panel.
Starting point
Where to begin
Assessment
Window in a wall
Library… → Examples
Jamb, head or sill: Uf, Ψg and installation Ψ. Whole window: Uw and installed heat flow.
Library component
Library… → Windows / IGUs → IGU + frame
Place it, then choose Set up window analysis… in Window Analysis.
Frame you model yourself
Window Analysis… → ＋ Frame of my own
Uf and Ψg of a uniform section with assigned materials and indoor/outdoor boundaries.
Use one example per Rhino document. A study solves everything on assigned layers together. The library and analysis forms stay open while you work in the document that owns them.
1. Place a window or IGU
Open Library…. The Examples tab provides complete editable setups, including window jamb, head, sill and whole-window examples with a wall, installation joint, boundary volumes and assessment cases.
Examples include geometry, boundaries and their assessment.
The Windows / IGUs tab places a component into your own model. Choose IGU + frame or IGU only, then a full 3D window or cut detail. Choose the frame system and compatible glazing, check the pane stack and dimensions, then click the placement button and an insertion point in Rhino.
Choose a component for your own model; review its glazing and source information before placing.
The IGU and frame form a read-only library unit on one layer; surrounding walls, installation joints and boundary volumes remain editable. An IGU-only component lets you model a frame around the glazing. Component placement adds no wall or assessment. Select the placed IGU + frame in Window Analysis… and choose Set up window analysis… to add its boundary volumes, measurement guides and calculation cases once.
Import from WINDOW… accepts reviewed koala.glazing-system version 1 JSON. Imported glazing is stored in the document and available in both library tabs where it fits the frame. Native WINDOW .w4 and .mdb files need conversion first; they cannot be opened directly. Existing placed units keep their own property snapshots.
Command shortcuts: KoalaExamples and KoalaWindows open the corresponding tab in the same library window.
2. Draw the reference measurements
Choose Window Analysis… or run KoalaWindowAnalysis. Select the window, then Frame and glazing edge · Uf, Ψg or Installation in the wall · Ψ. Selecting an assessment view keeps the other cases.
Draw the references in Rhino using the buttons beside the measurements.
Each input has a coloured label and an explanation matching the diagram. Choose Draw line… beside a length and click its two ends in Rhino. The same button creates a measurement or replaces an existing or missing one.
Reference
What to measure
bf · Projected frame width
From the outer frame edge to the visible-glazing edge (sightline).
bg · Visible glazing width
From the sightline to the model’s glazing cut. Keep at least 190 mm of visible glazing.
bp · Panel reference width
The visible reference width used when the glazing is replaced by an insulation panel for Uf.
Wall reference length
For installation Ψ, from the wall’s cut to the frame’s outer edge, using the assessment’s stated dimension convention.
New picks remember their endpoints inside the assessment and add no Rhino point, curve, dimension or layer. Temporary viewport dimensions show extension lines, ticks, names and values in the document’s units. Focus an input or choose Highlight to identify its guide. Typing a number instead makes a Fixed value with no spatial guide.
In Legend Settings → Measurement guides, choose While editing measurements (default), Always show, or Hidden. Always-visible guides work with the dialogs closed and before a simulation. The preference is saved with the document and is independent of thermal-result visibility.
Whole-window Uw
Select Whole window · Uw. Its reference is the projected outer-frame area: the area inside the outer frame, excluding the wall and installation joint.
Uw uses the projected outer-frame area, excluding the surrounding wall.
Draw outline… takes three outer-frame corners to define a rectangle. Pick outline… copies an existing closed planar curve. The outline is remembered in the assessment, or you can enter a fixed area. Whole-window cases report Uw and installed heat flow separately; a 3D corner or mullion crossing does not automatically provide separate Uf, Ψ or χ values.
Assess a frame you have drawn
Place an IGU only → Cut detail from the library. Model the frame as solids around its edge, with at least 190 mm of visible glazing. Place the IGU’s layer above the frame layers so that the glazing unit takes precedence in overlapping regions.
Assign frame materials and indoor/outdoor boundary volumes. Every solid and boundary must describe the same uniform extrusion.
Choose Window Analysis… → ＋ Frame of my own, name the assessment, and draw its projected frame width and visible glazing width.
Use Pick point… on plain glazing away from the frame and spacer. KOALA traces the centre-glass Ug and reference-panel Up at that point.
Complete the missing items, then choose Calculate window analysis. Existing frame assessments appear in the same list and are edited in place.
Uf uses a second case with the glazing replaced in the background by an insulation panel, λ = 0.035 W/(m K). No panel solid is added to the model. For frame-profile voids, the layer menu’s Assign frame air cavities (automatic)… resolves each connected cavity on the grid; local layer cell sizes help resolve thin profile walls.
3. Calculate and report
The form lists what is still needed. Once the references are complete, choose Calculate window analysis. It runs the configured cases of the shared thermal study, including any other thermal bridges. Results appear in the form, panel log, viewport and Report… window. With Verify enabled, the cases are also solved at half the cell size.
Simulate model in the form, or Simulate in the panel, still solves heat flow and temperatures when window measurements are incomplete. KOALA reports that window analysis is unavailable and withholds Uf, Ψg, installation Ψ and Uw instead of reusing old reference values. The setup remains available for repair.
Open Report… to enter project information, add named views and section drawings, and review the pages. Export PDF, CSV tables, report JSON or the complete study with its inputs. An optional ISO 13788 check in the report runs a separate surface-temperature calculation. See Results and reporting for report preparation, saved fields and export procedures.
The EnergyPlus IDF export can write a WindowProperty:FrameAndDivider object from a section’s Uf and Ψg. A window-in-wall detail can export the wall construction with its installation Ψ distributed over the stated perimeter and wall area. Whole-window Uw is stated in the report.
Save and repair references
Measurements, outline and setup survive switching details and reopening the Rhino document. Remembered measurements are snapshots of your picks: draw them again after geometry changes. Older object-backed guides show Follows its measurement in Rhino and follow edits to their source objects.
A missing reference shows a question mark and a repair instruction. Use its Draw line…, Pick point… or outline control to replace it, then calculate again. Changes to geometry, assignments, cell size or setup make an existing result obsolete. Recalculate after reopening; use the panel’s .kvox controls when you also need to save or load a solved field.
Scope and limits
Library dimensions and material recipes are illustrative unless their source record states otherwise. They are starting points for modelling, not certified complete windows. Source classifications do not certify your edits, generated corners or installation details.
Glazing uses the selected recipe’s fixed gap properties and reference conditions; changing temperature or tilt does not automatically recalculate gas and coating performance. Window and cavity calculations are thermal-only and skip Glaser vapour diffusion. Uf and Ψg need a uniform section; independent reference comparisons and mesh refinement remain necessary for detailed frames.
For general linear and point bridges on your own geometry, follow the Ψ / χ workflow. For the panel, layers and mesh controls, return to the Rhino guide.
