Andersen Home Additions & ADU in South Florida, FL

Andersen Home Additions & ADU: The South Florida Owner’s Guide

Andersen windows and doors are specified in most South Florida home additions and ADU projects we build, with installed packages for these expansions typically running $45,000-$130,000 depending on footprint and finish level. We stock Andersen A-Series, E-Series, and 400 Series components for same-day resolution of hardware, sash, and frame issues that threaten your addition’s weather seal. Most homeowners first notice a problem when they feel Gulf Stream humidity seeping through a window that used to lock tight, or when a door sash starts dragging after a few South Florida wet seasons.

Call (844) 665-0162

Which Andersen Models This Applies To

Andersen’s product stack for additions and ADUs breaks into three tiers, and the parts are not interchangeable. The A-Series uses proprietary FSC-certified wood cores with fiberglass exteriors, part numbers stamped on the interior sash label starting with “A-“. The E-Series, formerly Eagle, runs aluminum-clad with the thickest extrusion Andersen offers, and its hardware is metric-threaded, not the standard 10-32 used on the 400 Series. The 400 Series, still the workhorse for most South Florida additions, uses Perma-Shield vinyl cladding on wood, and its sash balancers carry a date code you’ll need for matching.

We carry OEM Andersen hardware and weatherstrip for all three lines. Aftermarket equivalents exist for 400 Series balancers and certain locks, but we don’t spec them for A-Series or E-Series, the tolerances are too tight and the coastal warranty voids if non-Andersen parts are detected during a claim. To identify your unit, open the sash and photograph the etched Andersen logo in the glass corner, the interior label, and any stamped metal on the lock mechanism. That trio tells us exactly what ships.

Signs Your Andersen Home Additions & ADU Is Failing

• Visible moisture between panes. The insulated glass unit’s edge seal has failed, common in South Florida where daily thermal cycling plus salt air degrades the butyl faster than inland climates. Andersen IGUs can be field-replaced without swapping the full sash on 400 Series units built after 2015, earlier frames often need the whole sash.
• Sash won’t stay open or slams shut. The balancer system, either a coil spring or block-and-tackle depending on series year, has lost tension. In coastal South Florida we see this at 8-12 years instead of the 20-year rating, salt corrosion accelerates fatigue in the spring housing.
• Lock engages but sash still shifts. The keep, the metal receiver the hook grabs, has wallowed out or the frame has settled slightly in the humid expansion. Sometimes it’s the lock mechanism itself, the zinc casting cracks at the hook pivot after repeated over-torquing.
• Door threshold holds water after rain. The composite or aluminum threshold cap has deformed, or the subsill drainage channels are packed with tropical debris. Andersen doors rely on positive drainage to the exterior, when that backs up the wood jamb starts wicking.
• Exterior cladding chalks or cracks. UV degradation of the vinyl or paint film, accelerated by South Florida’s UV index. On 400 Series this is cosmetic until water reaches the wood core, on A-Series it’s a warranty item if documented within the coverage window.

Replacement Cost & What’s Included

For Andersen window and door components within a South Florida home addition or ADU, here’s how pricing breaks:

The spread depends on unit size, whether we’re working from scaffolding on a second-story addition, and whether the original install left adequate service clearance. We quote upfront after inspection, no surprises. Our workmanship carries a one-year warranty, and Andersen OEM parts ship with their factory coverage intact. Full addition and ADU builds using Andersen products start at $45,000 and scale with footprint, finish, and whether you’re adding a kitchen or bath.

DIY or Call Us?

Here’s where we’ll be straight with you. An owner can safely inspect: photographing labels, checking for visible debris in drainage channels, and confirming the lock engages fully without forcing it. What we don’t recommend: removing a sash with failed balancers (the drop hazard is real, especially on a ladder), cutting out an IGU without understanding pressure equalization, or adjusting Andersen door hinges that carry the full weight of laminated impact glass. We’ve been called to jobs in Coral Gables and Fort Lauderdale where a well-meaning homeowner turned a $280 balancer call into a $1,400 sash replacement.

Raymond’s rule on every job site: do it right the first time or you’ll do it twice - and the second time always costs more. If you’re seeing any of the symptoms above, call (844) 665-0162. We’ll confirm the series, check stock, and get you scheduled.

FAQs