Due to high demand, tons of window manufacturers offer casement windows in their product lines. But which ones truly offer the best quality and performance?
Below, we’ve listed the top casement window manufacturers you can trust when buying windows for your home or business.
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8 Best Casement Window Manufacturers in 2025
Here’s a rundown of the eight top casement window makers that stand out for their dedication to high standards, new ideas, and customer satisfaction.
1. Marvin Windows
- Location: Warroad, Minnesota, USA
- Company Type: Manufacturer
- Year Founded: 1912
- Number of Employees: 7,000+
- Main Products: Windows, doors, and custom building solutions
This 1912 family-owned business has developed a reputation for innovation and environmental prudence. They have casement windows in 5 product lines, but their “Ultimate Casement window” stands out for its special “wash mode,” which allows you to clean it from the inside.
Then the “Elevate” series is a combination of fiberglass and wood construction, whereas the “Essential” series is made of fiberglass only. The “Coastline series” is hurricane-proof. Marvin also offers casement windows in corner and Skycove orientation. Most of the models also feature Low-E coatings and insulated glass for optimal thermal performance.
2. Mannlee
- Location: Foshan, Guangdong, China (operating across the USA)
- Company Type: Manufacturing
- Year Founded: 1998
- Number of Employees: 300
- Main Products: Windows, doors, and energy-efficient products
Mannlee may not be on your radar as some of the larger names on the list, but the company has managed to build quite a global presence after almost thirty years of production. One of the defining characteristics of Mannlee’s strategy is a focus on sustainable and yet affordable bespoke windows.
In order to meet these standards, Mannlee has equipped modern manufacturing facilities and has a competent workforce of more than 300 personnel who specialize in their line of work. They are given multiple quality management certificates of approval by Global organizations such as AAMA, SAI Global, and UL, which stand as a testament to them. Mannlee serves both residential and commercial clients, placing their name alongside leading window manufacturers.
3. MILGARD
- Location: Tacoma, Washington, USA
- Company Type: Manufacturing
- Year Founded: 1962
- Number of Employees: 1,000-1,500
- Main Products: Windows, doors, patio doors
MILGARD provides casement windows in several materials. The V450 HomeMaker Series is vinyl with double-foam compression bulb seals, the A250 is thermally enhanced aluminum, and the C650 Ultra™ is a fiberglass frame. The V250 Style Line Series® is constructed of vinyl and features a slender frame.
But the flagship products are vinyl Tuscany® Series and Trinsic™ Series, especially favored for a clean modern look. The price is deemed mid-range and they have varying warranties based on series.
4. Alside
- Location: Cuyahoga Falls, Ohio, USA
- Company Type: Manufacturing
- Year Founded: 1947
- Number of Employees: 1,000+
- Main Products: Windows, doors, and siding
Alside has casement windows in their vinyl replacement window line, Mezzo, the Sheffield and Ultramaxx series, and the Fusion series, available at different budgets. However, the core material remains vinyl, infused with their proprietary thermal insulation, ClimaTech. The products are distributed in all 48 States through distributors.
You will also receive a limited, transferable warranty for your lifetime on certain products. However, vinyl as a exclusive frame material could restrict their popularity among some consumers.
5 Pella Corporation
- Location: Pella, Iowa, USA
- Company Type: Manufacturing
- Year Founded: 1925
- Number of Employees: 10,000+
- Main Products: Windows, doors, trim, and building products
Pella Corporation possesses over 150 patents and has been ranked among the “Most Innovative Design Companies”. Its casement windows are included in Architect Series®, 850 Series®, Lifestyle Series, and Impervia Series in wood-clad or fiberglass design. Pella has invented the Steady Set for smooth operation in its casement windows and also provides built-in blinds with its Easy-Slide Operator.
6. Andersen Windows and Doors
- Location: Cottage Grove, Minnesota, USA
- Company Type: Manufacturing
- Year Founded: 1995
- Number of Employees: 13,000
- Main Products: Windows and doors
This company’s entrepreneurial spirit is evident in its proprietary material, Fibrex®, wood-and-vinyl composite that provides wood strength with vinyl’s low-maintenance factor. Its 100 Series casement windows employ Fibrex, but its best-selling 400 Series, A-series, and E-Series come in aluminum, vinyl, and wood construction. The casement windows also feature hinges that enable the sash to open a full 95 degrees for optimum ventilation.
Anderson also caters to window replacement and installation services via a sister company, Renewal by Andersen.
7. Universal Windows
- Location: Bedford Heights, Ohio, USA
- Company Type: Manufacturing
- Year Founded: 2002
- Number of Employees: 50-200
- Main Products: Windows, entry doors, and home improvement
This Ohio manufacturer offers window products, exclusively under the brand name UniShield, which retails seven different styles of windows. Energy efficiency is a main priority for UniShield, realized through their Super Spacer technology, a triple seal system with Low-E glass coatings. The disadvantage is that they only provide vinyl framing which might not be the preferred material for all.
Primarily, Universal Windows service in the Midwest, but now also venturing into some major cities nationwide.
8. Gilkey
- Location: Cincinnati, Ohio, USA
- Company Type: Manufacturing
- Year Founded: 1978
- Number of Employees: 150+
- Main Products: Windows
Gilkey also primarily serves in the Midwest, though you can find some products on the East side too. Their casement window product line revolves around their “Signature Series,” which also includes awning windows.
The frames are all made of fiberglass with a DP 90 rating. They offer multiple glazing options up to 1 3/8 inches thick, sufficient to withstand 220 mph winds. They also provide Lifetime Limited and transferable warranties and have a mid-to-high price range.
Wrap Up
All the casement window manufacturers we’ve included in the list exemplify innovation, tenacity, and customer satisfaction. If you’re interested in specific products, go to their website and communicate with the seller for more specifics.
If you’re still not sure where to begin, we suggest looking into Mannlee. The brand has a vast range of doors and windows that are both stunning and reliable.
