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CGI Home Additions & ADU: The San Diego Owner’s Guide
If you have a CGI-built home addition or ADU in San Diego and something has failed, you need a contractor who understands how CGI structures are framed, flashed, and finished, not a generalist who will guess. We work on CGI home additions and ADUs throughout San Diego, and the typical repair or renovation on these structures runs $53,100 – $153,400 depending on scope, structural condition, and finish level. Most owners discover a problem through a water stain, a sticking door, a cracked drywall seam, or a floor that suddenly feels soft underfoot. The good news is that CGI additions are built to a known system, so the failure is almost always traceable to a specific detail: a flashing transition, a settling pier, a siding joint, or a roof tie-in that was never sealed correctly in the first place.
We are an independent San Diego remodeling contractor with deep experience in CGI-built additions and accessory dwelling units. We are not affiliated with CGI, but we know their framing packages, their typical connection details, and where those details fail in San Diego’s coastal marine layer and dry inland heat. If you need a diagnosis, a repair, or a full renovation of your CGI structure, call us at (619) 604-9624 and we will walk the job with you.
Which CGI Models This Applies To
CGI home additions and ADUs in San Diego are built from prefabricated panel systems, typically light-gauge steel or engineered wood, with factory-cut wall panels, floor cassettes, and roof trusses that arrive on site and are craned or hand-set into place. The key compatibility issue is not a model number; it is the panel connection system and the original plan set. If your addition was permitted through the County of San Diego or the City of San Diego, those plans are on file and we can pull them to identify exactly which CGI panel series was used, what the load paths are, and what the original flashing details specified.
There is no functional aftermarket for CGI structural panels. When a panel is compromised, the repair uses the same gauge steel or same engineered lumber specified on the plan set, cut and fabricated to match on site. What does vary is the finish work: any CGI addition in San Diego can be re-sided, re-roofed, re-flashed, or re-trimmed using standard trade materials as long as the structural panel itself remains sound. The practical question we answer on almost every CGI call is whether the failure is in the structural system or the envelope, because that determines whether the repair is measured in thousands or tens of thousands.
Styles & brands we work with
Signs Your CGI Home Additions & ADU Is Failing
- Water staining at the wall-to-roof intersection. This is the most common CGI failure we see in San Diego. The transition between the prefabricated wall panel and the site-built roof framing is a frequent leak point, especially on ADUs built before 2020 before stepped kick-out flashing became standard practice.
- Door or window that sticks or rubs. CGI panels are rigid. When a door starts binding in its frame, something has moved: a pier has settled, a sill plate has shifted, or the panel was never properly anchored. In San Diego’s expansive clay soils, seasonal movement is real, and a sticking door is often the first clue.
- Drywall cracks running diagonally from a corner. Diagonal cracking is not a cosmetic issue. It indicates shear or racking movement in the wall plane. On a CGI addition, this often traces to missing hold-down hardware or a panel that was not fully connected at the top plate.
- Soft spot in the floor near a doorway or plumbing penetration. Floor cassettes in CGI ADUs are typically engineered wood I-joists with OSB decking. Water intrusion at a threshold or a toilet flange rots the OSB from below, and by the time the vinyl or tile feels soft, the decking is already compromised.
- Visible rust streaking on an exterior steel corner or sill. If your CGI addition used light-gauge steel framing, any rust streak means the galvanized coating has failed at that point. Near the coast in Point Loma or Ocean Beach, salt air accelerates this, and a small rust streak can signal a structural loss of section over time.
See the difference
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AfterReplacement Cost & What’s Included
In San Diego, repairing or renovating a CGI home addition or ADU typically runs $53,100 – $153,400. The spread is wide because the work ranges from envelope repairs (re-flashing, re-siding, window replacement) to structural remediation (panel replacement, foundation stabilization, roof tie-in rebuild). A small water-damage repair at a single flashing point might land at the low end. A full ADU gut-renovation with kitchen and bath, new windows, new siding, and structural corrections will push toward the top of that range.
Every quote includes a written line-item price before work starts. You see the labor, the materials, the permit fees if permits are required, and the disposal costs, so the number on day one is the number on the invoice. We do not work on verbal estimates, and we do not hand you a change order surprise after demo day. The work carries our 365-Day Done Right Promise in writing: if something we touched fails inside a year, we come back and make it right at no charge.
Call (619) 604-9624 for a written quote on your CGI addition or ADU. The estimate is free, the walkthrough is free, and the number you get is the number you hold us to.
DIY or Call Us?
There are a few things worth checking yourself: visible water stains after rain, a door that only sticks in one season, a musty smell in one corner. Those observations help us diagnose faster. What you should not do is cut into a CGI wall panel, attempt to re-flash a roof tie-in, or jack up a corner of the structure. CGI panels are load-bearing systems. Cutting a steel stud or removing a section of OSB decking without understanding the load path can compromise the structure of the entire addition, and a failed jacking attempt can crack drywall, bind doors, or worse.
High work, structural work, and any work that involves removing a panel or opening an envelope should be handled by a trained professional. Tell me what you need, I’ll tell you what it costs, and we’ll go from there. Call (619) 604-9624 and we will schedule a walkthrough at your property. Background-checked, uniformed technicians on every job, and a written price in your hand before anyone picks up a tool.
FAQs
A properly detailed and maintained CGI addition or ADU in San Diego will serve for the life of the home, but the envelope components need replacement on shorter cycles: roofing 20 – 30 years, siding 15 – 30 years depending on material, windows 20 – 25 years. The structural panel system should last indefinitely if it stays dry. Water intrusion at the flashing transitions is what shortens the lifespan of these structures in San Diego, not the panels themselves.
In many cases, yes. If the issue is surface rust on a steel stud or localized OSB rot in a floor cassette, the affected section can often be sistered or patched per the original plan set and current San Diego building code. If the panel has lost structural section across a wide area or the connection points have corroded, replacement of that panel section is the correct repair. We will tell you which one you actually need, because the price difference is significant, and we have no incentive to sell a replacement when a repair is structurally sound.
Small envelope repairs, like a re-flashed wall-to-roof intersection or a replaced window, typically take one to three working days. Structural panel remediation can run two to four weeks, and a full ADU renovation can take ten to fourteen weeks from permit approval through final inspection. Permits through the City of San Diego or the County, when required, add time before work starts, and we pull those permits for you. Call (619) 604-9624 for a realistic timeline on your specific repair, and we will give you a written schedule along with the written price.
We do not stock CGI structural panels, because there is no aftermarket parts inventory for prefabricated structural systems; every panel is fabricated to match your original plan set. What we do keep on hand in our San Diego shop is the trade material that CGI structures need for envelope repairs: flashing, sealants, trim stock, common window and door sizes, and siding in the most-used profiles. For kitchen and bath remodels inside CGI ADUs, we also install KraftMaid and Wellborn cabinetry, Cambria and Silestone countertops, and Kohler and Moen fixtures, so the finish work inside your addition carries the same written guarantee as the structural work outside.
If your CGI addition or ADU in San Diego is showing water damage, movement, or finish failure, call us at (619) 604-9624. We will send a background-checked technician to your property, give you a written diagnosis, and hand you a written price before any work starts. That is how we have operated since 2004, and it is how every job in San Diego goes: the number you get is the number you pay, and the work is guaranteed in writing for a year.
Written by Trevor Nash, Owner, Penhallow Remodeling San Diego at Penhallow Remodeling San Diego, serving San Diego and nearby areas.
