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Angled gable end and porch storm windows cut to your exact long leg, short leg, and bottom measurement. Memory vinyl panel in a 7/8″ aluminum lip mount frame, made to order.
All windows are made to order to your exact dimensions. Feel free to give us a call at 1-800-966-9261 or email your opening dimensions to us at info@deckbuilderoutlet.com. The window sizes on our dropdown menus are there to give you an idea on the approximate cost of the windows in that size range.
Your porch or gable end has an angled top, not a square one, and a standard rectangular storm window will not cover it. You need a panel with two legs of different lengths and a flat bottom, cut to your exact angle.
Liftgate delivery to your address
Custom built to your exact opening size
Frame & vinyl backed by Porch Conversions
These custom trapezoid storm windows are built for openings a standard rectangular window cannot cover, gable ends, angled transoms, and sloped sunroom walls where the top edge is not square. Each window is manufactured to order by Porch Conversions, a 7/8 inch extruded aluminum lip mount frame with an electrostatically painted finish and a memory vinyl panel.
A trapezoid window has three straight edges, a long leg, a short leg, and a bottom. There is no separate angle measurement to provide, the angle is set automatically once those three edges are cut to your numbers. The short leg has a six inch minimum so the frame corner has enough material to hold together.
These are exterior storm windows, the entire unit mounts from the outside of the opening the same way our rectangular storm windows do. If your opening is a true rectangle, that page is the right fit instead.
Manufacturer · Made in USA
Porch Conversions has been manufacturing porch enclosure systems for decades. Their rectangular storm windows are built specifically for screen porches, sunrooms, and old house applications, with heavy-duty aluminum frames, electrostatic finishes, and memory vinyl panels engineered to last.
A trapezoid storm window has three straight edges that matter: a long leg, a short leg, and a bottom. The short leg cannot be less than 6 inches. There is no angled top measurement to take, the angle is determined automatically once the three straight edges are set.
United Inch (UI) is your long leg plus your bottom plus your short leg, all in inches. If your total is under 70 UI, you pay the flat rate of $246.00 regardless of exact size. If your total is 70 or over, you pay $3.60 per united inch.
Formula for 70 UI and over:
(Long leg + Bottom + Short leg) × $3.60 = your price.
Example: 30″ long leg + 48″ bottom + 18″ short leg = 96 UI × $3.60 = $345.60.
| LONG LEG | BOTTOM | SHORT LEG | UNITED INCHES | TIER | PRICE |
|---|---|---|---|---|---|
| 10″ | 24″ | 8″ | 42 UI | Under 70 | $246.00 |
| 20″ | 36″ | 12″ | 68 UI | Under 70 | $246.00 |
| 30″ | 48″ | 18″ | 96 UI | Over 70 | $345.60 |
| 40″ | 60″ | 24″ | 124 UI | Over 70 | $446.40 |
| 54″ (max) | 72″ (max) | 34″ (max) | 160 UI | Over 70 | $576.00 |
Prices shown are base pricing before freight. Frame finish does not affect price. Contact us for a freight estimate to your zip code.
| SKU | Sty225V-T |
| Window Type | Fixed trapezoid exterior storm window |
| Long Leg | Maximum 54 inches |
| Bottom | Minimum 12 inches, maximum 72 inches |
| Short Leg | Minimum 6 inches, maximum 34 inches |
| Frame Material | Heavy-duty extruded aluminum |
| Frame Mount | 7/8″ lip mount, exterior installation |
| Finish | Electrostatic paint, chip, peel, and UV resistant |
| Glazing Panel | Memory vinyl, returns to flat after deflection |
| Pricing Method | United Inch, UI = long leg + bottom + short leg |
| Under 70 UI | $246.00 flat rate |
| Over 70 UI | $3.60 per united inch |
| Warranty | Manufacturer warranty, Porch Conversions |
| Lead Time | 4–5 weeks, custom made to order |
| Shipping | Common carrier freight, liftgate delivery |
| Country of Origin | USA |
A custom trapezoid storm window starts at $246.00 flat for any opening with a total of under 70 united inches (long leg + bottom + short leg). For larger openings, the price is $3.60 per united inch. For example, a 30″ long leg, 48″ bottom, and 18″ short leg (96 UI) costs $345.60. The largest available size, 54″ long leg, 72″ bottom, and 34″ short leg (160 UI), costs $576.00. Freight shipping is additional and depends on your location.
A trapezoid storm window is designed to cover angled openings that a standard rectangular window cannot fit. Common applications include gable ends above porch rooflines, angled transoms over doors, and sloped wall sections on sunrooms. It mounts and seals from the exterior the same way as a rectangular storm window.
You need three measurements: the long leg (the taller vertical side, up to 54″), the bottom (the flat horizontal edge, between 12″ and 72″), and the short leg (the shorter vertical side, between 6″ and 34″). There is no separate angle to measure. The angle is automatically determined by these three dimensions. See the How to Measure tab for the complete step-by-step guide.
The short leg requires at least 6 inches of material so the aluminum frame corner can be assembled correctly and remain structurally secure. If your opening tapers to a point smaller than 6 inches, contact us to discuss whether another product may be a better fit.
No. This product requires both a long leg and a short leg. A true triangle, where one side comes to a point, is not available as a standard configuration. If you have a triangular opening, call us to discuss your options.
Yes. If your opening is a true rectangle with no angled edge, our rectangular storm windows are the better option. They use the same aluminum frame and memory vinyl construction as our trapezoid storm windows.
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