Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Owens Corning Home Additions & ADU: The San Francisco Owner’s Guide
We install and finish Owens Corning insulation systems inside home additions and ADU projects across San Francisco, with most full-scale additions running between $53,100 and $153,400 depending on square footage, foundation work, and how far the existing structure needs to open up. When a homeowner calls us about an Owens Corning product that isn’t performing, it’s almost always the same story: the insulation was never installed at the right depth, the vapor barrier was skipped, or the original crew crushed the batts into a cavity that was too small. The cold wall in the nursery, the damp smell in the new ADU, the heat that won’t stay in the Sunset District back bedroom – those are the clues.
We’re an independent contractor in San Francisco, not a corporate Owens Corning outlet, which matters because we don’t have a quota to sell you a particular product line. What we stock and install is based on what the room actually needs. And every project starts with a written price before any work begins, so there are no surprises on the back end.
Which Owens Corning Models This Applies To
Most San Francisco additions and ADUs we see use Owens Corning PINK Fiberglas batt insulation, either the R-13 for 2×4 walls, R-19 for 2×6 walls, or R-30 for ceilings and attic spaces. The type is printed on the facing paper, right next to the Owens Corning name – if you can see the word “EcoTouch” or “Thermafiber,” that tells you which product line you have. For exterior walls on larger additions, we also work with Owens Corning FOAMULAR rigid foam board, typically the 250 series, which we install under siding or behind stucco where the San Francisco Building Code calls for a continuous insulation layer of R-5 or better.
The biggest compatibility gotcha we run into is this: older Owens Corning batts with the kraft facing were sized precisely to the 16-inch on-center framing of their era, and if you try to use a modern “fits 15-1/4 inch” batt in an older cavity, you compress it, and the R-value drops noticeably. The other failure point is in the facing itself – if the paper or foil facing on your existing Owens Corning batts is torn or peeling, the vapor barrier is compromised, and San Francisco’s fog belt will push moisture straight into your wall cavity. That’s a repair, not a re-insulation, and it’s usually less expensive than people expect.
Styles & brands we work with
Signs Your Owens Corning Home Additions & ADU Is Failing
- Cold spots on interior walls during the morning marine layer. Compressed or settled batts leave gaps at the top of the wall cavity, and San Francisco’s west-side fog finds those gaps fast. The root cause is almost always a batt that was forced into a cavity that was too small or a wall where the insulation slid down over time.
- Damp or musty smell in the ADU after heavy rain. The kraft facing on Owens Corning batts is the vapor barrier, and when it tears, moisture moves through the wall. In a standalone ADU near the ocean, like the Outer Sunset or Parkside, this happens faster than people expect.
- Energy bills that climb every winter while the furnace runs constantly. R-13 in a 2×4 wall loses a lot of its effective resistance once it’s compressed or gapped. San Francisco’s mild climate hides this problem until Pacific Gas & Electric starts sending the January statements.
- Visible gaps between batts or batts that have pulled away from the studs. If you can see daylight or a void behind the drywall at an outlet cutout, the original install was rushed, and air is moving through the wall like the insulation isn’t there.
- Rodent or pest activity in the ceiling joists. Owens Corning batts don’t attract pests, but a poorly sealed addition leaves entry points, and once mice or rats nest in fiberglass, the material holds the odor and needs to come out. We see this a lot in garage conversions where the original sill plate was never sealed.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
For a home addition or ADU in San Francisco, the full project range is $53,100 to $153,400, and the Owens Corning insulation work is usually a $2,600 to $7,400 line item inside that larger number, depending on whether you’re re-insulating existing walls or insulating new framing. Where it gets more expensive is when we’re opening walls to get to failed insulation – Sheetrock removal, re-insulating, patching, and retexturing adds $4,720 to $9,440 depending on the room. A garage conversion falls into the $35,400 to $94,400 range, and the insulation portion there typically runs $1,800 to $5,900 because the ceiling and walls is where the heat loss lives.
What’s included in our insulation portion: removal and disposal of failed material, air-sealing of top plates and penetrations, new Owens Corning batts or foam board matched to the cavity depth, and a written line-item price before we start. No change orders later. Our 365-Day Done Right Promise covers the insulation work, and every job ends with a photo of the clean-up before the crew leaves, so you can see what we left behind.
DIY or Call Us?
You can safely check the thickness of the batts yourself – if you have access to an attic or an unfinished wall cavity, measuring the depth tells us a lot. What you shouldn’t do is tear out faced insulation without a respirator and eye protection, and you shouldn’t guess at the vapor barrier, because getting that wrong in San Francisco’s coastal climate means mold behind the drywall two years later. Insulation work is low-risk compared to electrical or gas, but the compounds that make Owens Corning batts fire-resistant and the fiberglass itself can irritate skin and lungs pretty badly without the right gear, and compression errors will void the manufacturer’s R-value warranty.
If you’re not sure what’s in your wall and you’re seeing the symptoms above, call us at (831) 480-4497. We’ll come look at it and tell you straight whether it’s a repair or a replacement, and what it’ll cost in writing.
FAQs
Owens Corning batts and foam board are rated to last the life of the building – 50 years or more – as long as they stay dry and uncompressed; in San Francisco’s fog-heavy neighborhoods, the practical lifespan drops to about 20-30 years if the vapor barrier was installed incorrectly or the bays weren’t air-sealed. Call us at (831) 480-4497 and we’ll inspect yours and tell you what’s actually going on.
In many cases, yes – if the batts are intact but gaps have opened at the top of the wall or the facing is torn in one small area, we can repair and re-seal without a full replacement, which usually runs a few hundred dollars instead of a few thousand. The honest answer depends on how much moisture has gotten in, and we’ll only know that once we look.
For a standalone insulation replacement in a finished room, the work typically takes one to two days, including removal, air-sealing, new Owens Corning batts, and cleanup; for new construction insulation inside a full addition, we’re usually in and out in a day once the framing and electrical rough-in pass inspection. Quiet tools stay quiet, and we schedule around your family’s sleep hours where we can.
We stock Owens Corning EcoTouch R-13, R-19, R-30 batts, and FOAMULAR 250 board on our trucks for San Francisco jobs, and we can order any specific Owens Corning product from our local supplier within one to two business days – but for most additions and ADUs, what’s on the truck is what’s in your walls. If you need a specific series or R-value, tell us when you call and we’ll have it loaded before we arrive.
If your Owens Corning insulation isn’t doing its job in a San Francisco home addition or ADU, call us at (831) 480-4497 for a free estimate. Graham Stein will come out, look at the walls, tell you what’s wrong and whether it’s a repair or a replacement, and put the price in writing before any work starts. Tell me what the room needs to do, and we’ll figure out the rest from there.
Written by Graham Stein, Owner, Elmstead Remodeling San Francisco at Elmstead Remodeling San Francisco, serving San Francisco and nearby areas.
