SketchUp THERM/DXF Exporter

Version 1.0

What is this plugin?

The SketchUp THERM/DXF Exporter is a comprehensive tool for thermal modelling that bridges SketchUp's 3D modelling capabilities with LBNL's THERM thermal analysis software. It enables architects, engineers, and building scientists to create accurate 2D thermal models with proper material properties and boundary conditions.

This plugin is provided as-is for thermal modeling purposes. Use at your own risk. Always verify exported models in THERM before using for analysis or compliance. Email [email protected] for support or use the Support Ticket system.

Key Features

Dual Export Formats: Export to THERM XML (.thmx) or DXF
51 Predefined Materials: Complete thermal materials library with accurate conductivity and emissivity values
6 Built-in Boundary Conditions: Standard interior and exterior conditions
Full BC Management: Create, edit, duplicate, delete, and organise boundary conditions
Visual Feedback: Colour-coded materials and BCs with labels and legends
Entity Info Integration: View material and BC properties directly in SketchUp's Entity Info panel
Validation Tools: Pre-export validation and comprehensive diagnostics
Persistent Data: Automatic saving and loading of BC assignments

System Requirements

SketchUp 2021 - 2024
Windows
THERM 7.8 (optional, for opening exported files)

Access (Free)

Download the plugin here

Installation

Installation Steps

Download THERM_DXF_Export_1.0.rb
Open SketchUp
Go to plugin folder = C:\Users\xxxxxxx\AppData\Roaming\SketchUp\SketchUp 202x\SketchUp\Plugins
Add plugin

First Launch

After installation, restart SketchUp and the plugin will:

Create a working directory: Documents/SketchUp_THERM_Files/
Create subdirectories for materials and boundary conditions
Load with default settings
Add menu items under Plugins → THERM/DXF Exporter
Saved file = C:\Users\xxxxxxx/Documents/SketchUp_THERM_Files

Verification

Check the Ruby Console (Window → Ruby Console) for:

======================================================================
✓ THERM/DXF Exporter v1.0.0 loaded successfully!
======================================================================
  Materials: 46 (with visible colors)
  BCs: 7 (0 custom, 0 disabled)
  Edge Assignments: 0 loaded
  Default BC: Adiabatic (auto-assigned to unassigned edges)

✓ ENHANCED BC MANAGEMENT:
  Full control over boundary conditions database
  Create, edit, duplicate, and delete any BC
  Disable/restore built-in BCs

✓ ENHANCED COLOR VISIBILITY:
  All light materials now visible in THERM!

FEATURES:
  • Entity Info Display - Shows material/BC info in Entity Info panel
  • BC Management - Full database control
  • Validation & cleanup tools

EXPORT FORMATS:
  • THMX - Full THERM model with materials & BCs
  • DXF  - Geometry only (use Ctrl+T / Cmd+T)

Access via: Plugins → THERM/DXF Exporter
Files save to: C:\Users\xxxxxxxx/Documents/SketchUp_THERM_Files

Quick Start Guide

Basic Workflow (5 Steps)

Step 1: Create Material Collection

Go to Plugins → THERM/DXF Exporter → Materials → Create Material Collection
This creates 51 thermal materials in your model
Materials are organised by category (Metals, Insulation, Wood, etc.)
Restart SketchUp

Step 2: Apply Materials to Faces

Select 'Top' and 'Parallel Projection' Camera view
Draw faces
Select faces in your model
Use SketchUp's Paint Bucket tool
Choose THERM materials from the Materials browser
Paint each face with appropriate thermal material

Step 3: Assign Boundary Conditions to Edges

Select edges that represent thermal boundaries
Right-click → Assign THERM Boundary Condition
Choose appropriate BC (Interior, Exterior, etc.)
Optionally set U-Factor tag
Choose whether to auto-assign to unassigned edges

Step 4: Validate Model

Go to Plugins → THERM/DXF Exporter → Validate Model
Review any errors or warnings
Fix issues as needed

Step 5: Export

Go to Plugins → THERM/DXF Exporter → Export → Export to THERM (THMX)
Name your file
Choose cross-section type
Select post-export action
Click OK

Export Functions

Export to THERM (THMX)

Purpose: Creates a complete THERM 7.8 XML file with geometry, materials, and boundary conditions.

Menu Path: Export → Export to THERM (THMX)

Export Options:

File Name: Base name for the exported file (no extension needed)
Cross-Section Type: Other, Sill, Head, Jamb, or Frame
After Export:
- Open Folder: Opens export directory
- Launch THERM: Starts THERM application
- Do Nothing: Completes silently
Auto-assign Adiabatic: Automatically assigns adiabatic BC to any unassigned edges

What Gets Exported:

All face geometry (converted to polygons)
Material properties (conductivity, emissivity)
Boundary conditions with heat transfer coefficients
U-Factor tags
Temperature conditions
Cross-section metadata

File Location: Documents/SketchUp_THERM_Files/[filename].thmx

THERM Import Settings: Files are ready to open directly in THERM 7.8 (no import settings needed)

Export to DXF

Purpose: Creates a geometry-only DXF file compatible with AutoCAD and THERM.

Menu Path: Export → Export to DXF

Keyboard Shortcut:

Windows: Ctrl + T

What Gets Exported:

Face geometry only (polylines)
No materials or boundary conditions
2D geometry in SketchUp's internal units (inches)

THERM Import Settings:

Option 1 (Recommended):
Scaling: 2540%
Units: mm
Option 2:
Scaling: 100%
Units: inches

Use Cases:

Geometry verification
Import into other CAD software
Quick geometry sharing
Manual material/BC assignment in THERM

Launch THERM

Menu Path: Export → Launch THERM

Purpose: Opens the THERM application without exporting.

Requirements: THERM path must be configured in settings.

Open Export Folder

Menu Path: Export → Open Export Folder

Purpose: Opens Windows Explorer / Finder to the export directory.

Default Location: Documents/SketchUp_THERM_Files/

Material Management

Material Library

The plugin includes 51 pre-defined thermal materials organised into 9 categories:

Metals (7 materials)

Aluminium: k=160 W/mK
Steel: k=45 W/mK
Stainless Steel: k=17 W/mK
Copper: k=380 W/mK
Brass: k=120 W/mK
Bronze: k=65 W/mK
Zinc: k=112 W/mK

Insulation (8 materials)

Insulation-Fibreglass: k=0.04 W/mK
Insulation-Mineral Wool: k=0.038 W/mK
Insulation-XPS: k=0.029 W/mK
Insulation-EPS: k=0.033 W/mK
Insulation-Polyurethane: k=0.023 W/mK
Insulation-Polyisocyanurate: k=0.022 W/mK
Insulation-Cellulose: k=0.039 W/mK
Insulation-Spray Foam: k=0.026 W/mK

Wood (6 materials)

Wood-Softwood: k=0.12 W/mK
Wood-Hardwood: k=0.16 W/mK
Wood-Plywood: k=0.13 W/mK
Wood-OSB: k=0.13 W/mK
Wood-Particleboard: k=0.17 W/mK
Wood-MDF: k=0.14 W/mK

Masonry (10 materials)

Concrete-Normal: k=1.4 W/mK
Concrete-Lightweight: k=0.8 W/mK
Concrete Block-Hollow: k=0.6 W/mK
Concrete Block-Solid: k=1.0 W/mK
Brick-Common: k=0.7 W/mK
Brick-Face: k=1.0 W/mK
Stone-Granite: k=2.8 W/mK
Stone-Limestone: k=1.5 W/mK
Stone-Sandstone: k=1.7 W/mK
Mortar: k=0.8 W/mK

Glass (3 materials)

Glass-Clear: k=1.0 W/mK, ε=0.84
Glass-Low-E: k=1.0 W/mK, εfront=0.1, εback=0.84
Glass-Tinted: k=1.0 W/mK, ε=0.84

Plastics (4 materials)

PVC: k=0.17 W/mK
EPDM Rubber: k=0.25 W/mK
Polyethylene: k=0.42 W/mK
Acrylic: k=0.2 W/mK

Boards (3 materials)

Gypsum Board: k=0.16 W/mK
Plaster: k=0.5 W/mK
Cement Board: k=0.25 W/mK

Membranes (2 materials)

Air Barrier Membrane: k=0.2 W/mK
Vapour Barrier: k=0.16 W/mK

Air (2 materials)

Air-Cavity: k=0.026 W/mK
Air-Still: k=0.024 W/mK

Default (1 material)

Default Material: k=0.5 W/mK

Material Operations

Create Material Collection

Menu Path: Materials → Create Material Collection

What it Does:

Creates all 51 THERM materials in the active model
Assigns accurate thermal properties to each
Sets visible colours for easy identification
Stores materials in SketchUp's materials browser
Organises materials by category

After Creation:

Access materials via Window → Materials → In Model
Materials persist with the model file
Can be applied using Paint Bucket tool

Show Existing Materials

Menu Path: Materials → Show Existing Materials

Purpose: Lists all THERM materials currently in the model.

Output Example:

Materials in Model:
============================================================

THERM MATERIALS (15):
------------------------------------------------------------
  • Aluminium (k=160.0 W/mK)
  • Gypsum Board (k=0.16 W/mK)
  • Insulation-Fibreglass (k=0.04 W/mK)
  ...

View Material Library

Menu Path: Materials → View Material Library

Purpose: Shows complete list of all 51 available materials organised by category.

Use Case: Reference guide for selecting appropriate materials.

Delete THERM Materials

Menu Path: Materials → Delete THERM Materials

Purpose: Removes all THERM materials from the current model.

Warning: This only removes materials from the model, not from assigned faces. Faces will retain their colours but lose thermal properties.

Use Case: Clean up model or start fresh with material assignments.

Boundary Conditions

Built-in Boundary Conditions

The plugin includes 6 standard boundary conditions:

Interior Conditions

Interior, upwards

Heat Transfer Coefficient: 10.0 W/m²K
Temperature: 20°C
Use: Ceiling surfaces (heat flow upward)
Colour: Red

Interior, downwards

Heat Transfer Coefficient: 5.882 W/m²K
Temperature: 20°C
Use: Floor surfaces (heat flow downward)
Colour: Light Red

Interior, horizontal

Heat Transfer Coefficient: 7.692 W/m²K
Temperature: 20°C
Use: Vertical wall surfaces
Colour: Pink

Exterior Conditions

Exterior, air

Heat Transfer Coefficient: 250.0 W/m²K
Temperature: 0°C
Use: Exposed exterior surfaces (high wind)
Colour: Green

Exterior, ventilated

Heat Transfer Coefficient: 7.692 W/m²K
Temperature: 0°C
Use: Ventilated cavity or sheltered exterior
Colour: Light Green

Exterior, ground

Heat Transfer Coefficient: 99999.0 W/m²K
Temperature: 0°C
Use: Ground contact (constant temperature)
Colour: Medium Green

U-Factor Tags

Available tags for U-factor calculations:

(blank)
Interior
Exterior
Frame
Glazing
Edge
Spacer
Wall
Sill
Head
Jamb

BC Assignment & Management

Assign BC to Edges

Menu Path:

Boundary Conditions → Assign & View → Assign BC to Edges
Right-click on selected edges → Assign THERM Boundary Condition

Steps:

Select one or more edges in model
Choose menu option
Select boundary condition from dropdown
Optionally select U-Factor tag
Choose whether to auto-assign to unassigned edges
Click OK

Visual Feedback:

Edges are coloured according to BC
Colour persists in model
Can be viewed in Entity Info panel

Auto-assign Feature:

When enabled, applies the selected BC to ALL edges that don't already have a BC assigned
Useful for quickly setting up models
Can be undone with Ctrl+Z / Cmd+Z

Show BC Assignments

Menu Path: Boundary Conditions → Assign & View → Show BC Assignments

Output Example:

Boundary Condition Assignments:
============================================================

Interior, horizontal: 12 edges
  h=7.692 W/m²K, T=20.0°C
  Category: Interior

Exterior, air: 4 edges
  h=250.0 W/m²K, T=0.0°C
  Category: Exterior

U-Factor Tags:
------------------------------------------------------------
  Interior: 8 edges
  Exterior: 4 edges

Total: 16 edges with BCs

List All BCs by Category

Menu Path: Boundary Conditions → Assign & View → List All BCs by Category

Purpose: Shows complete library of available boundary conditions organised by category.

Diagnose BC Issues

Menu Path: Boundary Conditions → Assign & View → Diagnose BC Issues

Purpose: Comprehensive diagnostic tool for troubleshooting BC problems.

Checks Performed:

Available BCs in database
Current BC assignments in memory
Invalid assignments (BCs that don't exist)
Model geometry statistics
File persistence (saved vs. memory)
Recommendations for fixes

Output Example:

======================================================================

AVAILABLE BCs IN DATABASE (6):
----------------------------------------------------------------------
  ✓ Interior, upwards
  ✓ Interior, downwards
  ✓ Interior, horizontal
  ✓ Exterior, air
  ✓ Exterior, ventilated
  ✓ Exterior, ground

BC ASSIGNMENTS (16):
----------------------------------------------------------------------
  Interior, horizontal: 12 edges
  Exterior, air: 4 edges

INVALID ASSIGNMENTS:
----------------------------------------------------------------------
  ✓ All assignments valid

MODEL GEOMETRY:
----------------------------------------------------------------------
  Faces: 5
  Unique Edges: 20
  Edges with BCs: 16
  Edges without BCs: 4

FILE PERSISTENCE:
----------------------------------------------------------------------
  Assignment File: ✓ Exists
    Saved assignments: 16
    Memory assignments: 16
    ✓ Match: true
  BC Database File: ✓ Exists
    Custom BCs: 2
    Disabled built-in BCs: 0

RECOMMENDATIONS:
----------------------------------------------------------------------
  • 4 edges still need BC assignment

Clear All Edge Assignments

Menu Path: Boundary Conditions → Assign & View → Clear All Edge Assignments

Purpose: Removes ALL BC assignments from all edges.

Warning: This action cannot be undone automatically (must reload from saved file).

Clear Invalid BC Assignments

Menu Path: Boundary Conditions → Assign & View → Clear Invalid BC Assignments

Purpose: Removes BC assignments that reference deleted or non-existent BCs.

Use Case: Clean up after deleting custom BCs or importing models with missing BCs.

Custom BC Management

Create Custom BC

Menu Path: Boundary Conditions → Manage BCs → Create Custom BC...

Parameters:

BC Name: Unique identifier for the BC
Category: Interior, Exterior, Ground, Frame, Glazing, Adiabatic, or Custom
Heat Transfer Coefficient (h): In W/m²K
Temperature: In °C
U-Factor Tag: Optional tag for U-factor calculations
Description: Text description of the BC
Include Convection: Yes/No
Include Radiation: Yes/No

Example - Creating a Custom Interior BC:

BC Name: Interior, low airflow
Category: Interior
h: 5.0 W/m²K
Temperature: 22°C
U-Factor Tag: Interior
Description: Interior surface with reduced air movement
Include Convection: Yes
Include Radiation: No

Edit BC

Menu Path: Boundary Conditions → Manage BCs → Edit BC...

Behaviour:

Custom BCs: Edits directly
Built-in BCs: Creates a custom copy (preserves original)

Use Cases:

Adjust temperature conditions
Fine-tune heat transfer coefficients
Update descriptions
Change U-Factor tags

Edge Reassignment: If you rename a BC, all edges assigned to the old name are automatically updated to the new name.

Duplicate BC

Menu Path: Boundary Conditions → Manage BCs → Duplicate BC...

Purpose: Creates a copy of an existing BC as a starting point for customisation.

Process:

Select source BC
Enter new BC name
New BC created with same properties but different colour
Edit the duplicate as needed

Use Case: Create variations of standard BCs (e.g., "Exterior, air" → "Exterior, air, low wind")

Delete BC

Menu Path: Boundary Conditions → Manage BCs → Delete BC...

Behaviour:

Custom BCs: Permanently deleted
Built-in BCs: Disabled (hidden but preserved)

Warning Check: If BC is currently assigned to edges, plugin warns you and recommends clearing assignments first.

Undo:

Custom BCs: Cannot be recovered (must recreate)
Built-in BCs: Can be restored using "Restore Disabled Built-in BCs"

Delete All Custom BCs

Menu Path: Boundary Conditions → Manage BCs → Delete All Custom BCs

Purpose: Bulk deletion of all user-created custom BCs.

Safety: Built-in BCs are not affected.

Confirmation: Requires OK/Cancel confirmation.

Restore Disabled Built-in BCs

Menu Path: Boundary Conditions → Manage BCs → Restore Disabled Built-in BCs

Purpose: Re-enables any built-in BCs that were previously deleted/disabled.

Use Case: Recover from accidental deletion of built-in BCs.

Reset Database to Defaults

Menu Path: Boundary Conditions → Manage BCs → Reset Database to Defaults...

Purpose: Complete reset of BC database to factory defaults.

What it Does:

Deletes ALL custom BCs
Restores ALL disabled built-in BCs
Keeps existing edge assignments (may become invalid)

Warning: This action cannot be undone!

Use Case: Start fresh after extensive customisation.

Show BC Management Summary

Menu Path: Boundary Conditions → Manage BCs → Show BC Management Summary

Output Example:

Boundary Condition Management Summary
============================================================

BUILT-IN BCs:
  Total: 6
  Active: 6
  Disabled: 0

CUSTOM BCs:
  Created: 3

AVAILABLE BCs: 9

ASSIGNMENTS:
  Edges with BCs: 20

DISABLED BUILT-IN BCs:
------------------------------------------------------------
  (None)

BC Import/Export

Export BC Database

Menu Path: Boundary Conditions → Import/Export → Export BC Database...

Purpose: Export all BCs (built-in + custom) to a JSON file for backup or sharing.

Output File: User-selected location, JSON format

Use Cases:

Backup before major changes
Share custom BCs with team
Transfer BCs between computers
Version control for BC library

Import BC Database

Menu Path: Boundary Conditions → Import/Export → Import BC Database...

Purpose: Import BCs from a previously exported JSON file.

Behaviour:

Imports only BCs that don't already exist
Skips duplicate BC names
Reports count of imported and skipped BCs

Use Case: Add custom BCs from colleagues or previous projects.

Save Edge Assignments

Menu Path: Boundary Conditions → Import/Export → Save Edge Assignments

Purpose: Manually save current edge BC assignments to file.

Note: Assignments are auto-saved after each change, but this allows manual save.

File Location: Documents/SketchUp_THERM_Files/BoundaryConditions/edge_assignments.json

Load Edge Assignments

Menu Path: Boundary Conditions → Import/Export → Load Edge Assignments

Purpose: Manually load edge assignments from file.

Behaviour:

Only loads if file matches current model GUID
Updates edge colours to match assigned BCs
Overwrites current assignments in memory

Use Case: Restore previous BC assignments after changes.

Visualisation Tools

Tagging and Labelling

Tag Faces with Material Info

Menu Path: Visualisation → Tag Faces with Material Info

What it Does:

Adds THERM material properties to face attributes
Creates a comprehensive legend as 3D text
Stores metadata in SketchUp's attribute system

Legend Contents:

Material name
Conductivity (W/mK)
Emissivity front
Emissivity back
Category
Face count

Legend Location: Positioned to the right of model bounds

Removal: Use "Clear Material Tags" to remove attribute data

Organise into Material Layers

Menu Path: Visualisation → Organise into Material Layers

Purpose: Automatically creates SketchUp layers based on material categories and assigns faces to appropriate layers.

Layers Created:

THERM-Metals
THERM-Insulation
THERM-Wood
THERM-Masonry
THERM-Glass
THERM-Plastics
THERM-Boards
THERM-Membranes
THERM-Air
THERM-Default
THERM-Uncategorised

Benefits:

Better model organisation
Quick visibility control
Layer-based selection
Professional presentation

Removal: Use "Remove THERM Layers" to delete layers and move faces back to Layer0

Show Complete Labels (Materials + BCs)

Menu Path: Visualisation → Show Complete Labels (Materials + BCs)

What it Creates:

Materials Legend: Positioned right of model
- Lists all materials used
- Shows conductivity values
- Displays face counts
BC Legend: Positioned below materials legend
- Lists all BCs assigned
- Shows h values and temperatures
- Displays edge counts
Face Labels: 3D text on each face
- Shows material name
- Positioned at face centre
- Offset slightly from surface
Edge Labels: 3D text on assigned edges
- Shows BC name
- Export Debug:
- Positioned at edge midpoint
- Labelled as "BC: [name]"

Group Name: "THERM_Material_Labels"

Removal: Use "Hide Labels/Legend"

Show Legend Only

Menu Path: Visualisation → Show Legend Only

Purpose: Creates legends without individual face/edge labels (cleaner visualisation).

Contents:

Materials legend with full details
BC legend with full details
No face labels
No edge labels

Use Case: Documentation, presentations, export to PDF/image

Hide Labels/Legend

Menu Path: Visualisation → Hide Labels/Legend

Purpose: Removes all visible labels and legends created by the visualisation tools.

What it Removes:

Material legends
BC legends
Face labels
Edge labels
Associated groups

Note: Does not remove face attribute tags - use "Clear Material Tags" for that.

Show Visualisation Summary

Menu Path: Visualisation → Show Visualisation Summary

Output Example:

THERM Visualisation Summary
============================================================

GEOMETRY:
  Total Faces: 25
  Tagged Faces: 25

LAYERS:
  THERM Layers: 5
    • THERM-Insulation
    • THERM-Wood
    • THERM-Boards
    • THERM-Membranes
    • THERM-Glass

LABELS:
  Status: Visible

ENTITY INFO:
  Status: Enabled

MATERIAL DISTRIBUTION:
  Insulation-Fibreglass: 10 face(s)
  Wood-Plywood: 8 face(s)
  Gypsum Board: 7 face(s)

Clear Material Tags

Menu Path: Visualisation → Clear Material Tags

Purpose: Removes THERM material attribute data from faces without affecting visual appearance.

What it Removes:

Face attributes (THERM_Display dictionary)
Material metadata
Property information

What it Keeps:

Face materials (visual appearance)
Geometry
Layers
BC assignments

Remove THERM Layers

Menu Path: Visualisation → Remove THERM Layers

Purpose: Deletes all THERM-prefixed layers and moves faces back to Layer0.

Process:

Identifies all layers starting with "THERM-"
Moves all faces on those layers to Layer0
Deletes the empty THERM layers

Confirmation: Requires OK/Cancel confirmation

Entity Info Display

Overview

The Entity Info Display feature integrates THERM material and BC information directly into SketchUp's native Entity Info panel.

Enable Entity Info Display

Menu Path: Entity Info Display → Enable Entity Info Display

What it Does:

Activates a selection observer
Monitors selected entities
Updates Entity Info panel in real-time
Shows THERM properties alongside SketchUp properties

How to Use:

Enable the feature via menu
Select a face or edge
Open Entity Info panel: Window → Entity Info
View THERM properties

Entity Info for Faces

When a face is selected, shows:

THERM Material: Material name
Conductivity: Value in W/mK
Emissivity (Front): Front surface emissivity
Emissivity (Back): Back surface emissivity
Category: Material category

Example:

Entity Info Panel:
--------------------
Face
Area: 2.4 m²
Layer: Layer0
Material: Insulation-Fibreglass

THERM Material: Insulation-Fibreglass
Conductivity: 0.040 W/mK
Emissivity (Front): 0.900
Emissivity (Back): 0.900
Category: Insulation

Entity Info for Edges

When an edge is selected, shows:

THERM Boundary Condition: BC name
Heat Transfer Coeff: h value in W/m²K
Temperature: Temperature in °C
Category: BC category
U-Factor Tag: If assigned

Example:

Entity Info Panel:
--------------------
Edge
Length: 100 mm
Layer: Layer0

THERM Boundary Condition: Interior, horizontal
Heat Transfer Coeff: 7.69 W/m²K
Temperature: 20.0 °C
Category: Interior
U-Factor Tag: Interior

Multiple Selection

When multiple entities are selected:

If all have same material/BC: Shows that material/BC info
If mixed materials/BCs: Shows count of different materials/BCs

Disable Entity Info Display

Menu Path: Entity Info Display → Disable Entity Info Display

Purpose: Deactivates the selection observer to improve performance if needed.

Clear All Entity Info

Menu Path: Entity Info Display → Clear All Entity Info

Purpose: Removes all THERM_Info attributes from all faces and edges in the model.

Use Case: Clean up before exporting model for other purposes.

Validation & Diagnostics

Validate Model

Menu Path: Validate Model

Purpose: Pre-export validation to identify potential issues before exporting to THERM.

Validation Checks:

Material Assignment

Faces without materials
Warning if any faces lack materials

BC Assignment

Edges without BCs
Warning for unassigned edges
Check for Interior and Exterior BCs
Warning if neither is assigned

Geometry

Checks if geometry is 2D (all Z coordinates equal)
Error if 3D geometry detected
Dimension checks (too small or too large)
Warning if dimensions < 1mm or > 100m

BC Database

Verifies all assigned BCs exist in database
Counts BC types used

Output Example:

Model Validation Report
============================================================

GEOMETRY:
  Faces: 5
  Size: 100.00mm x 2400.00mm

BOUNDARY CONDITIONS:
  Assigned: 16 edges
  Unassigned: 4 edges

  BC Types:
    - Interior, horizontal: 12 edges
    - Exterior, air: 4 edges

============================================================

WARNINGS:
  ⚠ 4 edge(s) have no BC
  ⚠ No faces have materials assigned

✓ Model can be exported (with warnings)

Validation Levels:

✓ Ready: No errors or warnings
✓ Can Export: Has warnings but no critical errors
✗ Fix Errors: Has critical errors that must be fixed

Pre-Export Behaviour:

If validation fails, export asks for confirmation
Shows all errors and warnings
Allows proceed or cancel

Debug Output

Location: Ruby Console (Window → Ruby Console)

Assignment Debug:

=== Assigning BC ===
BC: Interior, horizontal
U-Factor: Interior
Selected edges: 4
  Assigned to edge ID 12345: Interior, horizontal
  Assigned to edge ID 12346: Interior, horizontal
  Assigned to edge ID 12347: Interior, horizontal
  Assigned to edge ID 12348: Interior, horizontal
Total BC assignments in memory: 16

Export Debug:

=== Creating THERM XML ===
Faces to export: 5
Edge BC map size: 16
Available BCs: Interior, horizontal, Exterior, air
BCs to export: Interior, horizontal, Exterior, air
  Exported BC: Interior, horizontal (h=7.692, T=20.0)
  Exported BC: Exterior, air (h=250.0, T=0.0)
  Exported boundary 1: Edge 12345 -> Interior, horizontal (Polygon 1)
  Exported boundary 2: Edge 12346 -> Interior, horizontal (Polygon 1)
  ...
=== Export Complete ===
Total boundaries exported: 16
========================

Use Debug Output:

Monitor during assignment
Verify BC application
Troubleshoot export issues
Confirm boundary count

Settings & Preferences

Set THERM Path

Menu Path: Settings → Set THERM Path...

Purpose: Configure the location of THERM7.exe for automatic launching.

Default Locations Checked:

C:/Program Files/LBNL/THERM 7.8/THERM7.exe
C:/Program Files (x86)/LBNL/THERM 7.8/THERM7.exe
C:/Program Files (x86)/lbnl/THERM7.8/THERM7.exe

Manual Setup:

Click menu option
Browse to THERM7.exe location
Select file
Path is saved in SketchUp preferences

Set Geometry Offset

Menu Path: Settings → Set Geometry Offset...

Purpose: Add X and Y offset to exported coordinates (useful for positioning in THERM).

Parameters:

X Offset: Horizontal shift in millimetres
Y Offset: Vertical shift in millimetres

Default: 0, 0 (no offset)

Use Cases:

Position geometry away from origin
Align with existing THERM models
Create standard positioning

Example:

X Offset: 50 mm
Y Offset: 100 mm

Original point: (10, 20)
Exported point: (60, 120)

Show Preferences

Menu Path: Settings → Show Preferences

Output Example:

THERM/DXF Exporter Preferences
============================================================

VERSION: 5.2.0

THERM Path: C:/Program Files/LBNL/THERM 7.8/THERM7.exe

Geometry Offset:
  X: 0 mm
  Y: 0 mm

Export Dir: C:/Users/[Username]/Documents/SketchUp_THERM_Files
Materials: 51
BCs: 6 (0 custom, 0 disabled)

Entity Info Display: Enabled

EXPORT FORMATS:
  • THMX (THERM 7.8 XML)
  • DXF (AutoCAD/THERM compatible)

Working Directories

Main Directory:

Documents/SketchUp_THERM_Files/

Subdirectories:

Materials/ - Material library JSON files
BoundaryConditions/ - BC database and assignment files

Files Created:

edge_assignments.json - Edge BC assignments
boundary_conditions.json - Custom and disabled BCs
therm_materials_library.json - Material library
[filename].thmx - Exported THERM files
[filename].dxf - Exported DXF files

Troubleshooting

Common Issues

Issue: BCs Not Exporting to THERM

Symptoms:

THERM file opens but shows no boundary conditions
All edges appear as adiabatic in THERM

Solutions:

Check BC Assignments:
- Run Diagnose BC Issues
- Verify edges have BCs assigned
- Check Ruby Console for export output
Verify BC Database:
- Run List All BCs by Category
- Ensure BCs exist in database
- Check for invalid assignments
Re-assign BCs:
- Select edges
- Use Assign BC to Edges
- Verify colour change
Check Save Status:
- Manually run Save Edge Assignments
- Verify file created in BC directory
- Reload SketchUp and test again

Issue: Materials Not Appearing in THERM

Symptoms:

THERM file shows "Default Material" for all faces
Material properties incorrect

Solutions:

Verify Material Application:
- Use Show Existing Materials
- Confirm materials exist in model
- Check faces have materials applied
Recreate Materials:
- Run Create Material Collection again
- Reapply materials to faces
- Export again
Check Material Names:
- Material names must exactly match THERM database
- No typos or extra spaces
- Use materials from plugin, not custom materials

Issue: Geometry Not 2D

Symptoms:

Validation error: "Geometry is not 2D"
Export fails or creates incorrect THERM model

Solutions:

Check Z-coordinates:
- All vertices must have same Z value
- Usually Z=0
Flatten Geometry:
- Select all geometry
- Use Ruby Console:

ruby     Sketchup.active_model.entities.grep(Sketchup::Face).each do |f|
       f.vertices.each { |v| v.position.z = 0 }
     end

Work in 2D:
- Draw in XY plane only
- Lock inference to red/green axes
- Avoid inferencing to blue axis

Issue: Edge Assignments Not Persisting

Symptoms:

BC assignments disappear after closing SketchUp
Edge colours reset

Solutions:

Manual Save:
- After assigning BCs, use Save Edge Assignments
- Verify file created
Check Model GUID:
- Assignments are model-specific
- Saving model with different name creates new GUID
- Use Save As carefully
File Location:
- Verify write permissions to Documents folder
- Check antivirus not blocking file writes

Issue: THERM Won't Launch

Symptoms:

"THERM not found" error
Launch THERM option doesn't work

Solutions:

Set THERM Path:
- Go to Settings → Set THERM Path
- Browse to THERM7.exe
- Click OK
Verify Installation:
- Ensure THERM 7.8 is installed
- Check installation directory
- Try manual launch outside SketchUp
Use Alternative:
- Export file
- Use Open Export Folder
- Double-click .thmx file manually

Issue: Colours Too Light in SketchUp

Symptoms:

Some materials barely visible (especially insulation, air)

Solution:

Version 5.2.0 includes enhanced colours
All light materials updated for visibility
If using older version, recreate material collection

Issue: Ruby Console Errors

Common Errors:

Error: undefined method 'entityID' Solution: Selected object is not an edge or face, select correct geometry

Error: No such file or directory Solution: Working directory issue, verify Documents/SketchUp_THERM_Files/ exists

Error: JSON parse error Solution: Corrupted JSON file, delete and recreate (BC database or assignments)

Getting Help

Debug Information to Collect:

Ruby Console output (copy all errors)
SketchUp version
Plugin version (shown in About)
Diagnostic report output
Validation report output
Example model (if possible)

Contact:

Email: [email protected]
Include: Subject line "SketchUp THERM Exporter - [issue]"

Workflow Example

Example: Simple Wall Assembly

Goal: Create a 3-layer wall cross-section with interior and exterior BCs.

Steps:

Draw Geometry (2 minutes):

   - Rectangle: 100mm (width) x 2400mm (height)
   - Vertical lines at: 13mm, 103mm
   - Result: 3 vertical strips

Create Materials (30 seconds):

   - Materials → Create Material Collection
   - Confirms materials created

Apply Materials (1 minute):

   - Left strip (13mm): Gypsum Board
   - Middle strip (90mm): Insulation-Fibreglass
   - Right strip (13mm): Cement Board

Assign BCs (1 minute):

   - Select left vertical edge: Interior, horizontal
   - Select right vertical edge: Exterior, air
   - Select top edge: Interior, horizontal
   - Select bottom edge: Interior, horizontal

Validate (15 seconds):

   - Validate Model
   - Check: All green, ready to export

Export (30 seconds):

   - Export → Export to THERM (THMX)
   - File Name: wall_assembly
   - Cross-Section: Wall
   - After Export: Launch THERM

Result: Complete wall assembly opens in THERM with all materials and BCs correctly assigned.

Best Practices

Modelling

Always work in 2D:

Draw in XY plane (red-green)
Keep Z = 0 for all geometry
Use face-on view for accuracy

Use consistent units:

Set SketchUp units to millimetres
Model at actual size (1:1)
THERM uses millimetres

Create clean geometry:

No overlapping faces
No gaps between faces
No reversed faces

Name your sections descriptively:

Include location (sill, head, jamb)
Include project identifier
Use consistent naming convention

Material Assignment

Create materials first:

Run "Create Material Collection" before modelling
Materials persist with the model file
Can apply during or after modelling

Use correct material categories:

Match physical material to THERM material
Check conductivity values
Verify emissivity for radiation

Apply to all faces:

No face should be unpainted
Use Default Material as last resort
Validation will warn about missing materials

BC Assignment

Assign systematically:

Interior surfaces first
Exterior surfaces second
Special conditions last (ground, cavities)

Use U-Factor tags:

Tag all surfaces for U-factor calculations
Use "Interior" and "Exterior" at minimum
Tag frame components appropriately

Auto-assign for speed:

Use auto-assign for simple models
Manually assign for complex models
Review after auto-assignment

Save regularly:

Plugin auto-saves after changes
Manually save before major changes
Export BC database for backup

Validation

Validate before export:

Always run validation
Fix all errors
Address warnings when possible

Use diagnostic tools:

Run "Diagnose BC Issues" for troubleshooting
Check Ruby Console for detailed output
Review validation report carefully

Test export in THERM:

Open exported file in THERM
Verify materials show correctly
Check BC assignments and temperatures
Review U-factor tags

Organisation

Use layers:

Organise by material category
Easy visibility control
Better model management

Use scenes:

Create scenes for different views
Document material assignments
Show BC assignments

Create documentation:

Use "Show Legend Only" for reports
Export legend as image
Include in project documentation

Frequently Asked Questions

Q: Do I need THERM installed to use this plugin? A: No. The plugin works independently. THERM is only needed to open exported .thmx files.

Q: Can I use my own custom materials? A: Yes. Create custom materials using "Create Custom BC" but ensure thermal properties are correct.

Q: Why aren't my BCs exporting? A: Run "Diagnose BC Issues" to identify the problem. Common causes: BCs not assigned, invalid BC references, or edges not part of face boundaries.

Q: Can I import existing THERM files? A: No. This plugin is export-only. Draw geometry in SketchUp and export to THERM.

Q: What units does the plugin use? A: SketchUp uses inches internally. Export converts to millimeters for THERM. DXF exports in inches (use 2540% scaling when importing to THERM).

Q: How do I share my custom BCs with colleagues? A: Use "Export BC Database" to create a JSON file. Share this file and colleagues can import using "Import BC Database".

Q: Can I edit built-in BCs? A: When you edit a built-in BC, the plugin creates a custom copy. The original built-in BC remains unchanged.

Q: What's the difference between THMX and DXF export? A: THMX includes everything (geometry, materials, BCs). DXF is geometry-only for CAD software.

Q: My model has 3D geometry. Can I still export? A: THERM requires 2D geometry. Flatten your model to Z=0 before exporting.

Q: How do I backup my work? A: Export BC Database and save your .skp file. These contain all assignments and settings.

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Last updated 17 days ago

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