ROI Calculator — Cheat Sheet
Quick-reference cheat sheet for the ROI Calculator tool.
Published 27 May 2026
ROI Calculator
Quick-reference companion for the free Portal tool
What This Tool Does
The Blind Solutions ROI Calculator is an essential tool for South African architects looking to demonstrate the financial benefits of incorporating high-performance glazing and shading solutions into their designs. It quantifies the return on investment (ROI) by comparing energy savings, improved occupant comfort, and reduced operational costs against the initial investment of our advanced products.
Use this tool early in the design phase when presenting options to clients, especially for commercial, retail, or high-end residential projects where energy efficiency and sustainability are key drivers. It's invaluable for justifying the initial capital outlay for superior glazing and shading systems by illustrating long-term cost reductions and enhanced building performance. This tool is for any architect who wants to provide data-driven insights and strengthen their proposals with tangible financial projections.
Step-by-Step Usage Guide
Enter your project's basic information. For location, specify the city (e.g., "Johannesburg") or enter precise coordinates (e.g., -26.2041028, 28.0473051 for Johannesburg CBD). This helps the calculator fetch accurate climate data for energy calculations.
Select the building type (e.g., "Office," "Retail," "Residential") and input the primary orientation of the façade being analyzed (e.g., "North," "West"). This affects solar heat gain and daylighting potential.
Define the 'standard' or 'initial' glazing you're comparing against. This could be single-pane clear glass (e.g., 6mm clear float, U-value ≈ 5.7 W/m²K, SHGC ≈ 0.85) or a more common double-glazed unit (e.g., 6mm clear / 12mm air / 6mm clear, U-value ≈ 2.8 W/m²K, SHGC ≈ 0.76). Specify the total glazed area in square meters (e.g., 150 m²).
Select the Blind Solutions product you propose. This could be a specific type of low-E double glazing (e.g., "Low-E DGU, Argon-filled," U-value ≈ 1.6 W/m²K, SHGC ≈ 0.35) combined with an integrated shading system (e.g., "External Louvres"). The calculator will pre-populate typical performance values, but you can adjust if you have specific product data.
Input current electricity tariffs (e.g., R3.00/kWh for commercial). Specify the expected annual energy inflation rate (e.g., 8-10% in SA). Set the project lifespan (e.g., 20 years) and your client's desired discount rate for ROI calculations (e.g., 10%).
Click "Calculate ROI." Review the generated report which will show projected energy savings (kWh and Rands), carbon emission reductions, payback period, and Net Present Value (NPV). You can then export this report as a PDF for client presentations.
Common Scenarios & Expected Results
| Scenario | Input | Expected Output (Illustrative) |
|---|---|---|
| New Commercial Office (Johannesburg) | Location: Johannesburg Baseline: Standard Double Glazing (U=2.8, SHGC=0.76) Proposed: Low-E DGU with integrated blinds (U=1.5, SHGC=0.25) Glazed Area: 300m² West-facing Elec Tariff: R3.20/kWh |
Annual Savings: R75,000 - R100,000 Payback Period: 4-6 years ROI over 20 years: 150% - 200% Significant reduction in peak cooling load. |
| Residential Renovation (Cape Town) | Location: Cape Town Baseline: Single Glazing (U=5.7, SHGC=0.85) Proposed: Performance DGU (U=2.0, SHGC=0.40) Glazed Area: 50m² North-facing Elec Tariff: R2.80/kWh |
Annual Savings: R15,000 - R20,000 Payback Period: 6-8 years ROI over 20 years: 100% - 130% Improved thermal comfort, reduced HVAC reliance. |
| Retail Store Facade (Durban) | Location: Durban Baseline: Clear Laminated Glass (U=5.5, SHGC=0.80) Proposed: Solar Control Laminated with external shading (U=4.0, SHGC=0.20) Glazed Area: 120m² East-facing Elec Tariff: R3.50/kWh |
Annual Savings: R50,000 - R70,000 Payback Period: 3-5 years ROI over 20 years: 180% - 250% Reduced glare, enhanced product display, lower cooling costs. |
Pro Tips
Account for SANS 10400-XA: When defining your baseline, consider the minimum requirements of SANS 10400-XA for Fenestration. Using a compliant but basic DGU as your baseline often yields more realistic ROI figures for upgrades, rather than comparing against non-compliant single glazing.
Vary Energy Inflation: Don't just use a single energy inflation rate. Run scenarios with a range (e.g., 5%, 8%, 12%) to demonstrate the robustness of the investment against volatile electricity costs, a common concern in South Africa.
Beyond Energy Savings: While the calculator focuses on energy, remember to articulate the qualitative benefits in your client presentation. These include enhanced occupant comfort, increased productivity, better daylighting, reduced glare, and improved acoustic performance, which contribute significantly to building value but are harder to quantify directly in ROI.
Climate Zone Specifics: South Africa has diverse climate zones. Always ensure your location input is accurate. A high-SHGC product might be detrimental in hot, sunny regions (e.g., Limpopo) but acceptable in cooler, temperate areas (e.g., parts of Eastern Cape), reinforcing the need for precise data.