Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
CGI Home Additions & ADU: The Campbell Owner’s Guide
We stock and install CGI-compatible components for home additions and ADU projects in Campbell, with installed work typically falling between $45,000 and $130,000 depending on scope, and we can often begin assessment same-week for active failures. Most Campbell homeowners discover an issue when their addition’s window or door systems no longer seal properly against the coastal moisture that rolls in from the Santa Cruz Mountains, or when thermal expansion gaps appear after a few seasons of our wide temperature swings.
Which CGI Models This Applies To
CGI manufactures impact-resistant windows and doors under several series lines, and the part you need depends on when your home addition or ADU was built. The Estate Series, Sentinel Series, and WinGuard lines each use distinct frame extrusions and glazing packages that are not cross-compatible. Check the etched mark in the glass corner or the sticker on the frame jamb for a model prefix: ES-, SE-, or WG- followed by a four-digit size code. The Estate Series, common in Campbell additions from 2012 to 2019, uses a 3-1/4 inch frame depth that differs from the Sentinel’s 2-7/8 inch profile, so ordering by rough opening alone will get you a part that does not seat.
We source OEM CGI components direct from the Florida manufacturer, though for certain fixed-glass units we also stock PGT aftermarket equivalents that match the Miami-Dade impact rating at a lower per-unit cost. The decision hinges on whether your original unit carries a specific Florida Product Approval number required by your Campbell permit file. We check that before ordering.
Signs Your CGI Home Additions & ADU Is Failing

- Condensation between panes. The insulated glass unit’s edge seal has failed, which happens faster in Campbell than inland because our marine layer keeps exterior surfaces damp during morning temperature inversions. The desiccant inside the spacer bar saturates, and the view turns permanently foggy.
- Difficulty latching or dragging sashes. The balance system or hinge hardware has corroded, often from salt residue carried on afternoon bay breezes. The mechanism binds instead of gliding, and forcing it bends the track.
- Visible frame separation at corners. Thermal cycling between our 40-degree winter nights and 90-degree summer days stresses the mechanical corner joints. CGI’s earlier screw-and-plate corners are more prone to this than their later fusion-welded frames.
- Water staining on interior drywall below the unit. The weep holes are clogged with pollen and dust from the dry summers, or the sill pan was omitted during original installation. Water finds the path of least resistance inward.
- Cracked impact glass with intact laminate. The outer lite took a hit from debris or thermal stress, but the interlayer is holding. This is a safety success for impact-rated glass, though the unit still needs replacement to maintain the rating.
Before
AfterReplacement Cost & What’s Included
| Component | Campbell Range |
|---|---|
| CGI single window unit (installed) | $800 - $2,400 |
| CGI sliding glass door (installed) | $2,200 - $5,800 |
| Full addition window package (5-7 units) | $6,500 - $15,000 |
| ADU complete fenestration replacement | $12,000 - $28,000 |
| Glass-only IGU replacement (if frame is sound) | $340 - $780 |
The range reflects three factors: unit size, whether the original nail fin is intact or requires reframing, and whether your Campbell permit requires a current Florida Product Approval number that the original unit lacks. Our quote includes removal, disposal, new unit, sealant, interior and exterior trim repair, and a documented photo record of the rough opening condition before we close it up. Under Clause 1 of the Haven Standard, the price is written before anyone starts. The 365-Day Done Right Promise covers installation workmanship; the CGI factory warranty covers the unit itself.
DIY or Call Us?

An owner can safely check the model label and photograph any damage for documentation. Beyond that, CGI impact units weigh 40 to 80 pounds each depending on size, and the installation requires proper shimming, structural fastening to shear walls, and continuous sealant application that maintains the impact rating. Campbell’s building department will want to see the Florida Product Approval documentation on any replacement in an addition or ADU, and we include that permit support as standard.
Improperly installed impact windows fail structurally exactly when you need them to perform. We’ve replaced three DIY attempts in the Pruneyard area alone in the past year, each requiring reframing that added $1,800 to $3,400 to what should have been straightforward. If you’re weighing the decision, call (831) 704-1211 and we’ll walk through what your specific unit needs - no charge for the conversation.
FAQs
Expect 20 to 25 years for the frame and 12 to 18 years for the insulated glass unit seal in our specific conditions. The marine layer accelerates seal degradation compared to drier inland markets like San Jose proper, though CGI’s vinyl formulation resists UV better than earlier-generation products we’ve removed near the Los Gatos border. Call (831) 704-1211 for an exact quote on replacement - estimates are free.
If the frame is square, undamaged, and the model is still in production, we can often replace just the insulated glass unit. This saves 40 to 60 percent over full unit replacement. Discontinued series or frames with corner separation require complete replacement. We assess this on site and put both options in writing.
A single unit takes two to three hours on site; a full addition package typically spans two days. Campbell permit timelines add three to five business days for same-size replacement, longer if the opening changes dimension. We handle permit submission and inspection scheduling as part of our scope.
We stock common sizes of the Estate and Sentinel series for same-week installation once measured, and we maintain a local warehouse relationship for WinGuard and custom sizes with a five to seven business day turnaround. Exact-match IGUs for glass-only replacement require measurement and order, typically ten to fourteen days. Call (831) 704-1211 to confirm availability for your specific model.
Rowan Construction Group Campbell is an independent service provider and is not affiliated with CGI Windows & Doors. We also stock and install components for KraftMaid, Cambria, and Silestone systems.
Ready to get a written price before any work starts? Call (831) 704-1211 to schedule your free estimate. We’ll measure twice, document once, build it right - and you’ll have the number in writing before anyone picks up a tool.
Written by Grant Rowan, Owner, Rowan Construction Group Campbell at Rowan Construction Group Campbell, serving Campbell and nearby areas.







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