Free in-home measure and quote - PGT, CGI and CWS impact lines compared on your actual openings, style by style
CGI Custom & Geometric Windows in Miami Lakes: What to Know First
We provide independent CGI custom and geometric window service in Miami Lakes, with typical measured surveys scheduled within 48 hours and written quotes delivered before any work begins. Most custom CGI installations in this market run $2,800 to $7,500 per opening depending on shape complexity, impact rating, and whether the rough opening needs reframing. This page is for Miami Lakes homeowners who already own CGI products and need arched, curved, trapezoid, or oversized geometric units installed, replaced, or repaired correctly the first time. Call (786) 755-8730 to schedule your measured survey.
How CGI Products Fail - and How We Fix Them
- Sparta Series fixed geometric units: The thermal break in the frame extrusion separates at the weld corners on radius-top and hexagonal configurations after three to five Miami Lakes summers. We’ve traced this to the expansion differential between the aluminum frame and the PVC thermal insert when daily temperature swings exceed 25 degrees Fahrenheit, which is common here from April through October. We cut out the failed section, sleeve the joint with OEM-grade thermal break material, and re-weld with a documented photo record of the repair.
- Impact-rated custom shapes with laminated glass delamination: CGI’s impact-rated geometric units use thicker interlayers that can fog at the edge seal when installed with inadequate drainage slope, particularly on eyebrow arches above covered entries in Miami Lakes. The fogging starts at the bottom of the curve where water pools. We remove the sash, verify the weep path is clear of stucco or sealant blockage, reset the unit with proper 2-degree minimum slope, and replace the glass with a factory-authorized laminated unit if the interlayer has degraded.
- Sentinel Series operable arched units with binding hardware: The curved top rail on Sentinel casement and awning configurations puts asymmetric load on the roto-operator gearbox. After two to three years, the operator arm skips track or the gears strip, especially on units facing west that take the full afternoon thermal expansion. We replace with the correct CGI-specified Truth or Roto operator, never a generic box-store substitute that voids the warranty, and we shim the frame square before reinstalling.
- Oversized fixed geometric units with seal failure: CGI’s custom shop will build up to 60 by 120 inches on some lines, but the silicone structural seal on two-lite configurations can degrade faster than standard rectangles due to the differential movement at the center mullion. In Miami Lakes, we’ve found this accelerates when the interior side is kept at 72 degrees while the exterior face cycles through 95-plus days. We diagnose with a calibrated smoke pencil, document the leak path, and reseal with Dow Corning 795 or replace the lite if the desiccant is saturated.
- Coastal Series radius-top units with anodized finish chalking: The salt-air exposure in eastern Miami Lakes, particularly within two miles of the Palmetto Expressway corridor where wind carries residual salt, causes premature chalking on bronze and black anodized finishes. This is cosmetic but indicates surface degradation that will eventually compromise the anodized layer’s protection. We assess whether the substrate is still sound, then either refinish with a qualified architectural coating or quote a replacement sash with CGI’s current fluoropolymer finish, which holds up better in this specific environment.
Our CGI Custom & Geometric Windows Process

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Measured survey. Sonia Raman or a verified crew member arrives with a documented measuring protocol for radius, chord, rise, and springline dimensions. The customer keeps the survey sheet. We note rough opening squareness, plumb, and level to 1/16 inch.
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Parts diagnosis and sourcing decision. We determine whether the job requires OEM CGI components, factory-authorized equivalents, or quality aftermarket when OEM lead times exceed project schedules. We document the part number and source in the written scope.
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Written quote delivery. The price is fixed before any tool is lifted. Haven Clause 1: the measurement and the quote are the same document. No change orders.
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Installation with evidence. Verified crews install per CGI’s published installation instructions, not improvised methods. We photograph each stage: rough opening condition, shimming, fastening pattern, sealant application, and final sightline alignment.
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Hardware testing by second party. Sonia’s standing rule: she does not leave until the operating hardware has been tested by someone other than her. This catches binding, latch misalignment, or operator stress that the installer might miss.
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Documentation handoff. The customer receives the photo record, the completed warranty registration, and the 365-Day Done Right Promise in writing. Measure it right the first time or budget for the second trip.
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AfterWhat CGI Custom & Geometric Windows Costs in Miami Lakes
| Scenario | Typical Range |
|---|---|
| Standard geometric replacement (trapezoid, triangle, fixed) | $2,800 - $4,200 |
| Impact-rated radius-top or arch (single lite, up to 48″ wide) | $4,500 - $6,200 |
| Oversized custom fixed unit (over 48″ wide or 72″ tall) | $5,800 - $7,500 |
| Operable arched casement or awning with hardware replacement | $3,200 - $5,400 |
| Reframe or structural modification to rough opening | $800 - $2,400 additional |
What moves the price: impact rating versus non-impact, glass thickness and interlayer type, whether the geometric shape requires a custom die or can be fabricated from standard extrusion bends, and the condition of the rough opening. We also service PGT, CWS, ES Windows, and ECO Window Systems geometric units for comparison if CGI lead times or pricing don’t fit the project.
Call (786) 755-8730 for your written estimate. Estimates are free, and we provide a free second opinion on any competitor’s written quote.
Why Miami Lakes Homeowners Call Sightline Windows & Doors Miami Lakes for CGI Work

We’ve installed and serviced CGI products in Miami Lakes since 2012, including jobs on Main Street where historic-style storefronts require impact-rated units that don’t look like they belong on a warehouse. Our crew is background-checked, uniformed, and identified by license number before arrival under Haven Clause 3. Every job leaves a documented photo record, not as an upsell, as standard evidence. The 365-Day Done Right Promise is stamped on every invoice, not offered as a courtesy. Calls are answered by a live person, 24/7. And because we specify across eight manufacturer lines, we can compare CGI against PGT, CWS, ES Windows, or ECO Window Systems on the same written quote if the opening’s performance requirements allow alternatives.
FAQs
No, provided the work follows CGI’s published installation instructions and uses OEM or factory-authorized parts. As an independent CGI service provider, we document every component source and installation detail so your warranty claim, if needed, travels with evidence. Call (786) 755-8730 and we’ll review your specific CGI warranty terms at no charge.
Standard geometric configurations from CGI’s Florida facility typically ship in four to six weeks. Complex radius work or oversized custom dies can extend to eight to ten weeks. We quote the lead time in writing with the price, and we maintain relationships with CWS and ES Windows for geometric alternatives if your project schedule cannot accommodate CGI’s current production queue.
We repair when the frame is structurally sound and the glass or hardware failure is isolated. Replacement is necessary when the thermal break is compromised across multiple weld points, the anodized layer has degraded to bare aluminum, or the laminated glass interlayer has delaminated beyond the edge seal repair zone. We document both options with prices for each.
No. Haven Clause 1 means the measured survey and the written quote are the same document. The only price change occurs if you add scope, and that requires a signed amendment before work proceeds. We’ve maintained this since 2012 across 18,000-plus openings.
Our technicians carry license numbers you can verify, and we specify CGI by series and part number in the written scope, not generic descriptions. Sonia Raman reads the rough opening before she quotes it, not after, which keeps our change-order rate low and our documentation specific. You can also bring us a competitor’s written estimate for a free second opinion.
Written by Sonia Raman, Owner, Sightline Windows & Doors Miami Lakes at Sightline Windows & Doors Miami Lakes, serving Miami Lakes and nearby areas.










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