Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Therma-Tru Home Additions & ADU: The San Diego Owner’s Guide
If you’re planning a home addition or ADU in San Diego and want Therma-Tru doors and entry systems as part of the build, we handle the full scope: framing, rough openings, door installation, trim, and finishing. A home addition in San Diego typically runs $53,100 – $153,400, and an ADU runs $106,200 – $259,600 depending on size, site conditions, and finish level. Most owners come to us with a specific Therma-Tru product already picked out, or they’ve had a contractor walk away mid-project and the door openings are sitting unframed or incorrectly sized.
We’re an independent San Diego remodeling contractor, not a Therma-Tru dealer or affiliate. What that means for you: we spec and install Therma-Tru products because they hold up in coastal air better than most, but we don’t mark up the product line or push you toward a single series. We measure, order, and install whatever Therma-Tru door or entry system fits your addition or ADU plan, and the price is on paper before we start.
Which Therma-Tru Models This Applies To
Therma-Tru builds entry door systems, not just door slabs. For a San Diego addition or ADU, the relevant lines are the Classic-Craft, Fiber-Classic, and Pulse series. The Classic-Craft is their top line: a fiberglass door with a wood-grain face that takes stain like real oak or mahogany. The Fiber-Classic is the workhorse, smooth or textured, priced lower and spec’d on most rental ADUs we’ve built. The Pulse series is the mid-range option with a more contemporary profile, popular on modern additions in North Park and South Park.
Here’s the compatibility gotcha we see on a lot of San Diego jobs: Therma-Tru doors are sold as complete systems with a matching frame, sill, and weatherstrip. You can’t drop a Therma-Tru slab into an off-the-shelf big-box frame and expect it to seal or swing right. The door slab thickness, hinge prep, and sill profile are specific to the system. If a previous contractor roughed in a generic frame and you want a Therma-Tru door now, we usually pull the frame and set the full system. Trying to save the old frame costs more in callbacks than it saves in lumber.
On the OEM-versus-aftermarket question: for door slabs and frames, we order OEM Therma-Tru only. For weatherstrip, sweeps, and sill caps, quality aftermarket parts from brands like Endura and ProVia work fine and sometimes outlast the originals. We stock common sweeps and weatherstrip on the truck. Slabs and frames get ordered to spec, which takes a few days to a couple weeks depending on the series and finish.
Styles & brands we work with
Signs Your Therma-Tru Home Additions & ADU Is Failing
- Door drags or sticks at the bottom corner. This usually means the sill or the frame has settled, or the door slab has absorbed moisture. In San Diego’s marine layer zones like Point Loma and Ocean Beach, fiberglass doors are the right call specifically because they don’t swell like wood, but a poorly shimmed frame will still throw the slab out of square.
- Weatherstrip is flattened or cracked. Therma-Tru systems rely on compression weatherstrip at the jambs and head. Once it’s flat, air and moisture get in. On an ADU, that means higher cooling bills and dust inside the unit. Replacement is straightforward and we keep common profiles in the truck.
- Sill cap is loose or the threshold is wobbling. The sill takes foot traffic, sun, and sometimes standing water from sprinklers. A loose sill cap lets water under the door and into the subfloor, which is a much bigger repair than the sill itself.
- Door won’t latch without lifting the handle. This means the strike plate and the latch are no longer aligned. Sometimes it’s hinge wear, sometimes the frame has moved. Either way, forcing it wears the lock and the keeper, and eventually the door won’t secure at all. On an ADU you’re renting out, that’s a tenant complaint waiting to happen.
- Visible cracking or peeling at the door face or frame corners. Therma-Tru fiberglass doesn’t rot, but a bad paint job or a door hit by direct afternoon sun without a storm door can still look rough. If the fiberglass itself is cracked, that’s usually impact damage, not weathering, and the slab needs replacement.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
For an addition or ADU in San Diego, installed Therma-Tru entry door systems typically run $2,360 – $7,670 per opening, depending on series, glass options, and whether we’re setting a new frame or working inside an existing one. A full home addition runs $53,100 – $153,400. An ADU runs $106,200 – $259,600. Those are the numbers we put in writing before any work starts.
What drives the cost up: leaded or decorative glass, custom stain finishes, transom windows, and jobs where the rough opening was framed wrong and we have to reframe before the door goes in. What drives it down: a single standard 36-inch Fiber-Classic door with no sidelites, going into a clean opening we framed ourselves. Every quote includes the door system, frame, sill, weatherstrip, hardware installation, trim, and haul-away of the old door. We write the full scope and price on paper before work starts. If the door fails inside the first year, we come back and fix it at no charge under our 365-Day Done Right Promise. That’s in writing too.
DIY or Call Us?
Replacing a door sweep or weatherstrip on a Therma-Tru system is a reasonable Saturday project. You need a screwdriver, maybe a hacksaw for the sweep, and about 20 minutes. Setting a Therma-Tru pre-hung door is a different animal. It weighs more than a standard door, it has to be shimmed level and square in three planes, and the sill needs flashing or you’ll have water under it within a year. We’ve fixed enough DIY door installs in San Diego to know it’s not a beginner job. You’re dealing with a 300-pound unit, finish nails, and flashing tape, and if it’s off by a quarter inch, the door will never latch clean.
If you’re mid-addition or mid-ADU and the door openings aren’t right, or you want Therma-Tru doors spec’d from the start, call us at (619) 604-9624. We’ll send someone out to measure, talk through the series options, and get you a written price. Trevor Nash walks most San Diego job walks himself. Tell him what you need, he’ll tell you what it costs, and we’ll go from there.
FAQs
A properly installed Therma-Tru fiberglass door system lasts 25 – 35 years in San Diego’s coastal climate. The door slab itself won’t rot or swell like wood, which is the biggest advantage in marine layer zones. Weatherstrip and sweeps need replacement every 5 – 7 years, and the sill cap may need attention around the 10-year mark. Call (619) 604-9624 if you’re seeing wear earlier than that, because it usually means an installation or flashing issue, not a product defect.
Yes, most hardware-level failures are repairable. Weatherstrip, sweeps, sill caps, hinges, and strike plates are all replaceable parts, and we keep common profiles on the truck. If the fiberglass slab is cracked or the frame has water intrusion, replacement is the honest answer. We don’t push replacement when a $30 sweep fixes the problem. Call (619) 604-9624 and we’ll tell you straight which side of the line your door falls on.
A single pre-hung Therma-Tru door in a clean opening takes one day including trim and hardware. If we’re reframing the rough opening or adding a transom or sidelites, it’s typically two days. The lead time for the door itself depends on series and finish: Fiber-Classic doors are usually a few days to a week out, Classic-Craft with custom stain can take two to three weeks. We order the door before we schedule the crew so the slab is on-site the morning of install.
We don’t warehouse full door systems. We order OEM Therma-Tru slabs and frames per job, which keeps costs down and ensures you get the exact series, size, glass, and finish you spec’d. We do stock common weatherstrip, sweeps, sill caps, and hinge hardware in our service vans, so minor repairs on an existing Therma-Tru door can often be done same-day. For a new door, the order goes in the same day you sign the quote.
Written by Trevor Nash, Owner, Penhallow Remodeling San Diego at Penhallow Remodeling San Diego, serving San Diego and nearby areas.
