Therma-Tru Home Additions & ADU Nationwide

Therma-Tru Home Additions & ADU: The Pasadena Owner’s Guide

Therma-Tru entry systems in Pasadena home additions and ADUs typically run $45,000-$130,000 for a complete addition with integrated door package, or $90,000-$220,000 for a standalone ADU with full Therma-Tru specification. We stock Therma-Tru-compatible sidelite frames, adjustable thresholds, and multi-point locking hardware for same-day replacement on existing units. Most Pasadena owners discover a problem when the door drags after seasonal settling, or when the multi-point lock won’t engage after a few years of thermal cycling through our dry summers and occasional winter rains.

Call (562) 203-4508

Which Therma-Tru Models This Applies To

Therma-Tru categorizes their residential entry systems by door slab material: Classic-Craft (fiberglass with wood-grain embossing), Smooth-Star (smooth fiberglass for paint), and Fiber-Classic (the original fiberglass line). For Pasadena home additions and ADUs, we most often see Classic-Craft and Smooth-Star specified, with sidelite configurations ranging from 12-inch narrow profiles to full 36-inch venting sidelites. The critical identifier is the hinge-side label: a white sticker with a 12-digit SKU starting with the series prefix (CC for Classic-Craft, SS for Smooth-Star) followed by the door size, handing, and glass package code.

The multi-point locking hardware changed in 2019. Pre-2019 units used a two-bolt system with a stamped steel faceplate; 2019 and later use a three-bolt system with a reinforced zinc faceplate and wider 1-3/4 inch backset. The threshold assemblies are not cross-compatible between these generations. We carry both OEM Therma-Tru hardware and Hoppe aftermarket equivalents; the Hoppe system matches the post-2019 three-bolt pattern and carries a comparable 10-year finish warranty at roughly 15 percent less cost. For sidelite frames, we use only OEM Therma-Tru extrusions, the wall thickness on aftermarket frames runs thin and warps within two Pasadena heat cycles.

Signs Your Therma-Tru Home Additions & ADU Is Failing

• The door slab binds at the top corner in summer, then gaps in winter. This is the adjustable threshold losing its seal, or the composite frame swelling against a fixed jamb. In Pasadena’s 40-degree annual temperature swing, unsealed wood frames move; fiberglass slabs don’t, and something has to give.
• The multi-point lock handle lifts but the deadbolt doesn’t throw. The internal linkage rod has slipped at the center gearbox, usually from repeated over-travel of the handle. The gearbox itself is fine; the rod clip has fatigued. We stock the clip and the full rod assembly.
• Daylight visible under the door when closed. The adjustable threshold cap has cracked or the compression seal has flattened. Therma-Tru thresholds use a dual-durometer vinyl that stiffens after roughly 7-10 years of UV exposure, faster on south-facing ADU entries with no overhang.
• Condensation between sidelite glass panes. The insulated glass unit (IGU) seal has failed. This is not a door problem, but owners often misdiagnose it as one. The IGU is replaceable without disturbing the sidelite frame; we measure on-site and order to spec, typically 2-3 weeks.
• The door frame has pulled away from the rough opening, visible at the interior trim. This is installation failure, not product failure, but it presents as a door problem. In Pasadena’s older stock, particularly the raised foundation homes near Bungalow Heaven, seasonal moisture in crawlspaces moves the subfloor and the wall above it. The fix is re-anchoring through the jamb into structural framing, not shimming the trim again.

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Replacement Cost & What’s Included

The range on component work reflects three variables: the generation of hardware (pre-2019 units often need supplementary frame modifications), the finish color (Therma-Tru’s Slate and Midnight run 10-15 percent premium over white or almond), and whether the jamb is plumb within 1/8 inch or needs reframing. Under Clause 1 of The Haven Standard, we deliver a written line-item quote before any work starts; labor and materials are separated, and no change proceeds without a signed change order. Our 365-Day Done Right Promise covers the installation and the hardware function, not cosmetic damage from impact or neglect.

DIY or Call Us?

An owner can safely inspect three things: the hinge-side label for the SKU, the threshold cap for visible cracking, and the lock faceplate screws for looseness. Beyond that, Therma-Tru multi-point hardware carries enough spring tension to bruise a hand or strip the internal gearbox if the release sequence is wrong. The threshold adjustment screws are brass and strip easily if the cap is loaded with door weight while turning.

We’ve been called to Pasadena ADUs where a homeowner removed the entire lock body to “fix” a slipped rod, then couldn’t re-time the three bolts to the strike plate. The fix took 20 minutes with the right tools; the misassembly took two hours to undo. If you’re seeing binding, daylight, or lock failure, call (562) 203-4508. We’ll diagnose on-site, quote in writing, and stock most hardware for same-day completion.

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