The Truth About Simonton Windows: Design Pressure, Energy Performance & What Florida Homeowners Should Know

Joe Underwood • June 27, 2025

A deeper look at Simonton’s DP ratings, their history, ownership by Cornerstone Building Brands, and how they still compete as a reliable energy-efficient option.

If you’ve been shopping for new windows in Florida, chances are you’ve heard of Simonton—and if not, you’ve probably seen them in showrooms or mentioned in contractor quotes. They're one of the biggest names in vinyl windows, but if you live in Florida, especially near the coast or in a High Velocity Hurricane Zone (HVHZ), it’s important to understand what you’re actually getting.

So today, let’s take a closer look at Simonton Windows & Doors—who they are, their Design Pressure (DP) ratings, their energy performance, and what’s changed now that they’re under the Cornerstone Building Brands umbrella.

🏛️ Who is Simonton? A Brief History

Simonton started in 1946, founded in Pennsboro, West Virginia, as a family-owned business. Originally focused on aluminum windows, they shifted to vinyl in the 1980s—and that’s when they took off. Today, they’re known nationwide for vinyl window and door products, with many of their lines tailored toward the remodeling and replacement markets.

In 2014, Simonton was acquired by Ply Gem, and in 2018, Ply Gem became part of Cornerstone Building Brands, a mega-manufacturer with a portfolio of some of the largest names in building materials.

So while Simonton isn’t "small town" anymore, the brand still carries its original DNA: affordability, wide availability, and good performance for everyday American homes.

📉 The Concern: Simonton’s DP Ratings in Florida

Here’s the part most sales reps don’t talk about:

Simonton’s standard impact-rated products do not always meet the higher Design Pressure (DP) ratings required in some parts of Florida.

To translate that:

A window might be labeled “impact-rated” but still not pass for installation in certain HVHZ areas (High-Velocity Hurricane Zones) like coastal Broward or Miami-Dade without additional anchoring, upgrades, or code approvals.

For example:

Some of Simonton's impact models top out at DP 50–55, which may not satisfy local wind load requirements, depending on elevation and exposure.
Certain municipalities now require DP ratings of 60 or higher, particularly in coastal or open-terrain zones.

This doesn’t mean Simonton is a bad product—it means you need to pair the right model with the right install application and know your zoning.

At Windoor Retro Professionals, we always check local requirements and select products accordingly so your investment doesn’t fail an inspection (or worse—fail in a storm).

💡 Where Simonton Shines: Energy Efficiency & Aesthetics

Despite the DP concerns, Simonton offers exceptional energy efficiency in many of their product lines. Their windows regularly earn ENERGY STAR® certification, and many include features like:

Double-pane insulated glass with Low-E coatings
Argon gas fills for enhanced thermal performance
Fusion-welded frames and sashes for durability
Multiple grid and color options for custom appeal

In other words, if you live in inland Florida (Ocala, Orlando, Gainesville, etc.), and aren't subject to HVHZ code—but still want energy savings and impact protection—Simonton can be an excellent value.

🏢 Who Owns Simonton Now: Cornerstone Building Brands

Cornerstone Building Brands is the largest manufacturer of exterior building products in North America. They own:

Ply Gem
Simonton
American Craftsman
Atrium
Mastic
...and more.

This means better national logistics, product consistency, and long-term warranty support. In an industry where many small brands disappear after a hurricane season or a market dip, Simonton’s corporate backing is a real plus.

📈 Recent News & Updates on Simonton

Production expansion: Simonton has increased capacity at some of their plants to speed up lead times.
New product developments: Rumors are circulating that Cornerstone plans to rebrand and consolidate several of its window lines in the coming years, which may lead to improved engineering and DP performance upgrades.
Warranties remain strong: Simonton continues to offer double-lifetime warranties on many residential products, with solid track records of customer service when processed through authorized dealers.

🧠 Final Thoughts from Joe

Simonton is like that dependable friend who might not win an arm-wrestling contest, but is always there when you need them. They might not hit the highest DP ratings out of the box, but when installed correctly in the right setting, they’re energy-efficient, affordable, and reliable.

If you’re building on the coast and need Miami-Dade approval, we may recommend Eastern Architectural Systems, CWS by Pella, or PGT Innovations instead.

But if you’re inland and want great value with a reliable warranty and aesthetic options? Simonton is still one of the best bang-for-your-buck window brands on the market.

At Windoor Retro Professionals, we work with Simonton and dozens of other top window brands so we can match you with the product that best fits your home and location—not just one brand we’re pushing because it’s all we sell.