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ES Windows Home Additions & ADU: The Santa Clarita Owner’s Guide
ES Windows-compatible window and door systems for home additions and ADU projects in Santa Clarita typically run $45,000-$130,000 installed, depending on whether you’re extending an existing structure or building a detached unit. We stock ES Windows hardware, seals, and replacement sashes for the most common series used in local additions, and we carry the full catalog for jobs we didn’t install originally. Most Santa Clarita homeowners discover their ES Windows components are failing when they feel drafts around newly installed units in a Stevenson Ranch addition, or when the locking hardware on an ADU slider won’t engage after a few seasons of canyon dust and temperature swings.
Which ES Windows Models This Applies To
ES Windows produces several series relevant to Santa Clarita home additions and ADUs, and matching the right component starts with the label. Look for the etched mark in the glass corner or the stamped aluminum tag on the frame edge: the Series 5000 (single-hung and horizontal slider), Series 5500 (impact-rated for hillside zones), and Series 8000 (architectural fixed and casement) are the ones we see most often in local builds. The Series 5500 carries the Miami-Dade HVHZ rating, which matters in Santa Clarita because some HOA architectural committees in Valencia and Saugus now require documented impact resistance for any structure under 600 square feet.
OEM hardware from ES Windows ships on a 10-14 day lead time from their Florida facility. We stock quality aftermarket equivalents from Truth Hardware and Amesbury for same-day resolution on common failures: tilt latches, balance shoes, and weatherstrip compression seals. The aftermarket seals use Santoprene rather than PVC, which holds up better against the UV and dry heat that cracks OEM seals in 4-6 years on south-facing Santa Clarita additions. For impact-rated units, we specify OEM only - the interlayer and frame reinforcement are engineered as a system, and substituting voids the rating documentation your inspector will want to see.
Signs Your ES Windows Home Additions & ADU Is Failing

- Draft at the sill or meeting rail. The compression seal has hardened or the weep system is clogged with Santa Clarita’s fine alkaline dust. Water then pools in the track, accelerates seal degradation, and the thermal break loses contact.
- Locking hardware sticks or won’t fully engage. ES Windows’ multi-point locks rely on precise frame-square alignment; settling in a new addition’s foundation or seasonal expansion in an ADU’s lightweight framing throws the keepers out of register by 1/8 inch or less.
- Condensation between panes on dual-glazed units. The PIB primary seal has failed, allowing moisture past the desiccant-filled spacer. In Santa Clarita’s dry climate this usually means the unit saw thermal shock - east-facing ADU windows hit 40°F winter mornings then 75°F by 10 a.m.
- Sash won’t stay open or slams shut. The coil balance system has fatigued; ES Windows uses a constant-force balance in the Series 5000 that wears faster in additions with minimal overhang exposure.
- Visible frame separation at corners or miter joints. The structural silicone or mechanical fasteners have loosened. This is structural - the frame is no longer transferring wind load to the rough opening as designed.
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For a full ES Windows-equipped home addition in Santa Clarita, expect $45,000-$130,000 depending on square footage, foundation type (slab-on-grade versus raised on piers for hillside lots), and whether the unit is attached or detached. An ADU with ES Windows impact-rated throughout runs $90,000-$220,000. These ranges include permits, rough and finish carpentry, electrical to code, and the window package installed.
Component-level replacement - a single failed sash, hardware set, or seal replacement on an existing ES Windows unit - runs $180-$650 per opening depending on series and access. We itemize parts and labor separately on every quote: the hardware or sash at our cost plus 18%, labor at our published rate, and no change order without your signature. Under Clause 1 of The Haven Standard, that written price is locked before anyone touches a tool. Our 365-Day Done Right Promise covers the installation; ES Windows’ own warranty covers the glass and frame, which we register on your behalf.
DIY or Call Us?

There’s safe checking and then there’s work that belongs to a crew with the right documentation. A homeowner can verify the series label, photograph the failure, and clear weep holes with a pipe cleaner - that’s it. Removing an ES Windows sash requires releasing the balance shoe under spring tension; the constant-force coil stores enough energy to damage the frame or your hand if the tilt latch sequence is wrong. Impact-rated units add weight - a 36-by-72 Series 5500 slider weighs over 80 pounds - and the interlayer scratches if you set it on unfinished concrete.
We pull the permit, coordinate the inspection, and deliver a photo record of the rough opening condition, the installed unit, and the sealed perimeter. For ES Windows work in Santa Clarita, call (747) 294-3985 and we’ll schedule a free estimate with the written price before any work starts.
FAQs
Expect 15-20 years for standard series, 12-15 for impact-rated units exposed to direct sun on south or west elevations. The Santoprene aftermarket seals we use add 3-5 years over OEM PVC in this climate. Call (747) 294-3985 for an exact quote - estimates are free.
Field-applied sealants are a temporary patch at best; the glazing pocket geometry on ES Windows units requires factory-level disassembly to replace the PIB primary seal and desiccant spacer correctly. We replace the insulated glass unit as a whole. Call (747) 294-3985 for an exact quote - estimates are free.
A single sash or hardware replacement on an accessible ground-floor unit takes 2-3 hours. A full ADU window package on a new build is paced by the framing and inspection schedule, typically 6-10 weeks from permit to final. Call (747) 294-3985 for an exact quote - estimates are free.
We stock Truth Hardware and Amesbury aftermarket equivalents for Series 5000 and 5500 common failures; OEM ES Windows components ship on 10-14 day lead. We confirm availability before scheduling so you’re not waiting on a truck. Call (747) 294-3985 for an exact quote - estimates are free.
Rowan Construction Group Santa Clarita is an independent service provider, not affiliated with ES Windows. We also stock and install parts for KraftMaid, Cambria, and Silestone product lines.
Written by Grant Rowan, Owner, Rowan Construction Group Santa Clarita at Rowan Construction Group Santa Clarita, serving Santa Clarita and nearby areas.







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