BLIND SOLUTIONS
Facade Analyser — Cheat Sheet
Quick-reference cheat sheet for the Facade Analyser tool.
Published 27 May 2026
CHEAT SHEET
Facade Analyser
Quick-reference companion for the free Portal tool
What This Tool Does
The Blind Solutions Facade Analyser is an indispensable tool for South African architects, designed to rapidly assess the thermal performance, daylighting potential, and energy efficiency implications of various facade designs. It helps you make informed decisions early in the design process, ensuring compliance with SANS 10400-XA energy efficiency regulations and optimizing occupant comfort.
Use this tool when you're conceptualizing building envelopes, selecting glazing types, determining shading strategies, or needing to justify design choices to clients or authorities. It's crucial for projects aiming for green building certifications (like Green Star SA) or simply striving for energy-efficient, comfortable spaces across South Africa's diverse climate zones.
Step-by-Step Usage Guide
Step 1: Project Setup & Location
Begin by entering your project's location. This is critical for accurate solar path calculations and climate data. For instance, enter "Johannesburg" or specific coordinates like "26.2041° S, 28.0473° E" for precise solar angles.
Begin by entering your project's location. This is critical for accurate solar path calculations and climate data. For instance, enter "Johannesburg" or specific coordinates like "26.2041° S, 28.0473° E" for precise solar angles.
Step 2: Define Facade Orientation & Area
Specify the orientation of the facade you are analyzing (e.g., North, East, South, West). Input the total facade area in square meters. For example, a "West" facing facade with an area of "150 sqm".
Specify the orientation of the facade you are analyzing (e.g., North, East, South, West). Input the total facade area in square meters. For example, a "West" facing facade with an area of "150 sqm".
Step 3: Glazing Properties Input
Select your glazing type. Key parameters include U-value (W/m²K), SHGC (Solar Heat Gain Coefficient), and VLT (Visible Light Transmittance). For a typical double-glazed unit in Johannesburg, you might input: U-value "2.8", SHGC "0.45", VLT "0.65". Consider different options to compare performance.
Select your glazing type. Key parameters include U-value (W/m²K), SHGC (Solar Heat Gain Coefficient), and VLT (Visible Light Transmittance). For a typical double-glazed unit in Johannesburg, you might input: U-value "2.8", SHGC "0.45", VLT "0.65". Consider different options to compare performance.
Step 4: Wall & Shading Element Details
Input the U-value for the opaque wall sections (e.g., "0.5 W/m²K" for an insulated cavity wall). Crucially, define any external shading. This could be a horizontal overhang with a "1.2m" projection or vertical fins with "0.6m" depth. The tool will calculate their impact on solar gain.
Input the U-value for the opaque wall sections (e.g., "0.5 W/m²K" for an insulated cavity wall). Crucially, define any external shading. This could be a horizontal overhang with a "1.2m" projection or vertical fins with "0.6m" depth. The tool will calculate their impact on solar gain.
Step 5: Review & Interpret Results
After inputting all parameters, click "Analyse". The tool will generate a report detailing solar heat gain, daylight factor, and annual energy load estimations. Pay attention to the "Peak Solar Gain" and "Average Daylight Factor" for compliance and comfort.
After inputting all parameters, click "Analyse". The tool will generate a report detailing solar heat gain, daylight factor, and annual energy load estimations. Pay attention to the "Peak Solar Gain" and "Average Daylight Factor" for compliance and comfort.
Step 6: Iteration & Optimization
Adjust your inputs (e.g., try a lower SHGC glass, increase overhang depth) and re-run the analysis. This iterative process allows you to optimize your facade design for energy efficiency and occupant comfort, meeting SANS 10400-XA requirements.
Adjust your inputs (e.g., try a lower SHGC glass, increase overhang depth) and re-run the analysis. This iterative process allows you to optimize your facade design for energy efficiency and occupant comfort, meeting SANS 10400-XA requirements.
Common Scenarios & Expected Results
| Scenario | Input | Expected Output |
|---|---|---|
| North Facade - Winter Sun Optimization (Cape Town) | Location: Cape Town Orientation: North Glazing: Single Glaze, U=5.7, SHGC=0.75, VLT=0.85 Shading: No external shading |
High Winter Solar Gain (good for heating), but also high summer gain if not managed. Daylight factor likely high. Tool will flag potential overheating in summer. |
| West Facade - Overheating Control (Durban) | Location: Durban Orientation: West Glazing: Double Glaze, Low-E, U=2.2, SHGC=0.35, VLT=0.55 Shading: Vertical Fins, 0.8m depth, 1.5m spacing |
Significantly reduced afternoon solar gain compared to unshaded. Lower cooling loads. Moderate daylight factor. Tool shows effectiveness of vertical shading against low-angle western sun. |
| East Facade - Morning Sun Control (Pretoria) | Location: Pretoria Orientation: East Glazing: Double Glaze, U=2.8, SHGC=0.45, VLT=0.65 Shading: Horizontal Overhang, 1.0m projection |
Reduced early morning solar gain. Good balance of daylight and heat control. Tool demonstrates how horizontal shading effectively blocks high-angle morning sun. |
| South Facade - Glare & Daylight (Port Elizabeth) | Location: Port Elizabeth Orientation: South Glazing: Standard Double Glaze, U=3.0, SHGC=0.55, VLT=0.70 Shading: Internal Blinds only (not modelled by tool for external impact) |
Low direct solar gain. Primary concern is diffuse daylight and potential glare. Tool will show low solar heat gain, but highlight the need for internal glare control. |
Pro Tips
Climate Zone Specifics: Remember South Africa's diverse climate zones (SANS 10400-XA). A facade solution ideal for Cape Town (temperate, winter rainfall) might be detrimental in Musina (hot, arid). Always input the correct project location for accurate climate data specific to your region.
Iterate Glazing & Shading: Don't settle for the first option. Experiment with different U-values, SHGCs, and VLTs for your glazing. Combine this with various external shading strategies (overhangs, fins, louvres) to find the optimal balance for energy performance and occupant comfort.
Beyond SANS 10400-XA: While compliance is essential, consider going beyond minimum requirements. Aim for designs that reduce peak loads, minimize glare, and maximize natural light. This tool is excellent for demonstrating the value of enhanced performance to clients.
Multi-Facade Analysis: For complex buildings, analyze each significant facade orientation separately. The optimal solution for a north facade will likely differ significantly from a west facade. Then, integrate these findings into a holistic building design.