The Short Answer
Yes, impact windows can be retrofitted onto a home that already has older aluminum single-hung frames, but the existing frames almost always need to come out first. Swapping just the glass is rarely an option because impact-rated glass units are significantly heavier than standard glass, and old frames were never engineered to carry that load or meet today’s Florida Building Code wind pressure requirements.
Why the Old Frames Usually Have to Go
Older aluminum frames — especially anything installed before the mid-1990s in South Florida — were designed for lightweight single-pane glass. An impact glass unit is laminated, often with a PVB or SGP interlayer, and that extra weight adds real stress to every anchor point and corner joint. A frame that was fine for a 1/8-inch pane will flex, warp, or pull away from the rough opening under the same conditions that your new glass is supposed to survive.
The Structural Reality of Frame Replacement
When a licensed contractor does a full-frame removal, they’re also getting a look at the rough opening itself. That matters a lot in older homes. Rot in the wood buck, corroded fasteners, or cracked concrete around the opening — none of that is visible until the old frame comes out. Addressing those issues before setting new frames is what separates a quality installation from one that fails a few years down the road.
There’s also the permit and inspection side. Palm Beach County building inspectors will check that the new frame is fastened to a structurally sound substrate. If an inspector finds problems at that stage, you’ll have to pull the new frame back out anyway. Better to find it at demo.
What About Insert or Pocket Installations?
There is one scenario where the old frame stays: a pocket or insert installation. Here, the new impact window slides inside the existing frame opening. This approach works when the old frame is in genuinely solid condition, properly plumb, and the rough opening dimensions leave enough room for the new unit without reducing the glass area too much.
The trade-off is visible glass size. You lose an inch or more on each side, which can matter for rooms that depend on natural light or ventilation. Some Boca Raton homeowners in older developments choose pocket installs to avoid stucco patching and exterior repaint costs, which is fair — just go in knowing the limitations. A good contractor will measure, check the existing frame’s condition, and tell you honestly whether it qualifies.
What the Installation Process Actually Looks Like
For a standard full-frame replacement, here’s the general sequence. Demo day involves removing interior and exterior trim, then pulling the old frame. The opening gets inspected, repaired if needed, and prepped with the correct sealant backer. The new frame goes in, gets shimmed plumb and level, then fastened per the Florida Building Commission’s approved installation drawings. Glass units drop in last, sealed and glazed on-site.
Timeline and Disruption
A single window takes a crew about 45 minutes to an hour once the opening is clean. A whole-house project on a typical 3-bedroom home in the area usually runs two to three days depending on the window count and any surprises in the openings. Your contractor should pull the permit before any work starts and schedule the final building inspection after install. That inspection is what triggers the insurance discount with most carriers — skipping it leaves money on the table.
Curious about what specific products work best for older South Florida homes? The STS product lineup covers several frame and glass combinations suited to a range of opening types and home ages. You can also browse the FAQ for answers on what to expect during the permitting and inspection process.
If you want a contractor to look at your existing frames and tell you whether a pocket install is viable or a full replacement makes more sense, request a free quote and get eyes on the job before committing to anything.
The City of Boca Raton’s official site also has information on local building permits and inspection scheduling if you want to understand the municipal side of the process.
Related Questions
Do impact windows require new exterior stucco work after installation?
With a full-frame replacement, yes — there’s typically a small gap around the new frame that needs to be patched, sealed, and painted to match the exterior finish. The amount of stucco work depends on how the old frame was set and the size of the gap left behind. A pocket install avoids most of that exterior work, which is one reason some homeowners prefer it despite the smaller visible glass area.
Can you mix impact windows with regular windows in the same house?
Technically you can, but Florida’s building code requires that any opening that doesn’t have an impact-rated product must be protected by an approved shutter or storm panel during a hurricane. Insurance companies also scrutinize mixed installations — some will only offer the full premium discount if every opening is protected to the same standard. Most contractors and insurers recommend going all-in to avoid gaps in both coverage and protection.
