# Obstructions Add roof obstructions to accurately represent roof features. Obstructions prevent panel placement and affect shadow calculations, ensuring your solar design is realistic and accurate. ## What Are Obstructions? Obstructions are roof features that prevent solar panel placement, such as: - Roof vents - Chimneys - Skylights - HVAC units - Satellite dishes - Plumbing vents Accurately modeling obstructions is critical for: - Realistic panel placement - Accurate available area calculations - Proper shadow analysis - Permitting and approval ## Entering Obstruction Mode 1. Select a polygon (building structure) by clicking on it 2. Press `O` or click **Obstruction Mode** in the properties panel 3. Obstruction mode activates with the obstruction type selector 4. Press `F1` or `?` to toggle the help overlay > **Note:** You must have a polygon selected to enter obstruction mode. ## Obstruction Types Choose from these common obstruction types: ### Vent Standard round roof vent (plumbing vent, exhaust vent) - Typical size: 0.1-0.2m diameter - Common on all residential roofs ### Chimney Rectangular or square chimney structure - Typical size: 0.5-1.5m × 0.5-1.5m - Varies by type (fireplace, furnace, etc.) ### Skylight Roof window or skylight opening - Typical size: 0.5-2m × 0.5-2m - May be fixed or operable ### Square Vent Square-shaped vent (often larger exhaust vents) - Typical size: 0.3-0.6m × 0.3-0.6m - Common for bathroom or kitchen exhaust ### Turbine Vent Rotating turbine ventilation system - Typical size: 0.3-0.5m diameter - Common on industrial and commercial buildings ### Cupola Vent Decorative cupola-style ventilation structure - Typical size: 0.5-1.5m × 0.5-1.5m - Often found on barn-style or traditional buildings ### HVAC Unit Roof-mounted HVAC equipment - Typical size: 1-3m × 1-2m - Common on commercial buildings and some residential ## Placing Obstructions Follow these steps to add an obstruction: 1. **Select Type** - Choose obstruction type from the dropdown menu 2. **Adjust Dimensions** - Set width, height, and depth in meters 3. **Click Place** - Click the "Place" button to enter placement mode 4. **Click Location** - Click on the polygon surface where you want the obstruction 5. **Obstruction Placed** - The obstruction appears and prevents panel placement in that area > **Tip:** Adjust dimensions before placing. You can also edit dimensions after placement by selecting the obstruction. ## Obstruction Properties Each obstruction has customizable dimensions: ### Width Horizontal dimension (X-axis) in meters - Measured from left to right ### Height Vertical dimension (Z-axis) in meters - For 3D obstructions like chimneys and HVAC units - Affects shadow calculations ### Depth Depth dimension (Y-axis) in meters - Measured from front to back > **Note:** Dimensions are in meters. 1 foot ≈ 0.3 meters. ## Managing Obstructions ### Select an Obstruction Click on any obstruction to select it. Selected obstructions are highlighted and their properties appear in the panel. ### Edit an Obstruction 1. Select the obstruction 2. Modify dimensions in the properties panel 3. Changes apply immediately ### Delete an Obstruction Two ways to delete: - Select the obstruction and press `Delete` - Select the obstruction and click the delete button in the properties panel ### Clear All Obstructions Press `X` to clear all obstructions from the current polygon. This is useful when starting fresh or if you accidentally placed multiple obstructions. ## How Obstructions Work ### Panel Prevention Panels cannot be placed where obstructions exist: - The obstruction's footprint is marked as unavailable - Panels automatically avoid these areas - Helps calculate actual available roof space ### Shadow Casting Obstructions cast shadows during shadow analysis: - 3D obstructions (chimneys, HVAC) cast realistic shadows - Shadows move with sun position throughout the day - Affects panel production calculations ### Production Impact Obstructions reduce available space and may cast shadows: - Total available area is reduced - Some obstructions may shade nearby panels - System production estimates account for this ## Best Practices ### Place Obstructions Before Panels Always add obstructions before placing panels: 1. Create polygon 2. Add all obstructions 3. Then place panels This ensures panels automatically avoid obstruction areas from the start. ### Be Accurate Measure or estimate obstruction sizes as accurately as possible: - Use satellite imagery to estimate sizes - Refer to site photos or measurements - Conservative sizing is better than under-sizing ### Consider Shadows Larger obstructions (chimneys, HVAC) cast shadows: - Taller obstructions cast longer shadows - Consider shadow impact when reviewing panel placement - Use shadow analysis to visualize this ### Use Common Obstructions For typical residential roofs, common obstructions include: - 2-4 plumbing vents (standard vents) - 1 chimney (if applicable) - 1-2 HVAC units (on some homes) - 0-4 skylights (if present) ## Exiting Obstruction Mode To exit obstruction mode: - Press `Escape` - Or click outside the polygon - Obstructions remain on the polygon when you exit ## Keyboard Shortcuts | Shortcut | Action | |----------|--------| | `O` | Toggle obstruction mode (when polygon selected) | | `Delete` | Delete selected obstruction | | `X` | Clear all obstructions | | `F1` or `?` | Toggle help overlay | | `Escape` | Clear selection / Exit obstruction mode | --- **Next:** Add shading analysis with [[Trees]] or place panels with [[Panel Placement]].