Casement Windows with Mullions

When it comes to choosing windows for your home, casement windows with mullions are an excellent option to consider. These windows not only offer functionality and versatility, but they also add a touch of elegance to any space. In this blog post, we will explore the various benefits and features of casement windows with mullions to help you make an informed decision for your home.

What are Casement Windows with Mullions?

Casement windows are hinged windows that open outward, usually operated with a crank mechanism. Mullions, on the other hand, are vertical or horizontal bars that divide a window into multiple parts. When combined, casement windows with mullions create a beautiful and classic look.

Enhanced Design and Aesthetics

One of the major advantages of casement windows with mullions is their enhanced design and aesthetics. The addition of mullions creates a more traditional and sophisticated appearance. Whether you have a modern or traditional home, casement windows with mullions can complement any architectural style. The mullions add depth and character to the windows, making them a focal point of the room.

Improved Energy Efficiency

Another significant benefit of casement windows with mullions is their superior energy efficiency. The tight seal created when the windows are closed helps to prevent air leakage, improving insulation and reducing energy costs. This feature is particularly important in regions with extreme weather conditions.

Increased Natural Light

Choosing casement windows with mullions not only adds visual appeal but also increases the amount of natural light entering your home. The narrow spaces between the mullions allow for more glass, maximizing the window's surface area. This results in a brighter and more inviting living environment.

Improved Ventilation

Casement windows are known for their excellent ventilation capabilities. When the windows are fully opened, they can catch the breeze and direct it into your home, providing excellent natural ventilation. The mullions in casement windows do not obstruct the airflow, allowing for efficient air circulation throughout the room.

Easy Operation and Maintenance

Operating casement windows with mullions is a breeze. The crank mechanism makes opening and closing effortless, even for those with limited mobility. Additionally, cleaning and maintenance are simple due to the ability to fully open the window. You can easily access both sides of the glass, ensuring a thorough and convenient cleaning process.

Durability and Security

Casement windows with mullions are built to last. They are typically constructed from high-quality materials like aluminum, vinyl, or wood, providing durability and strength. The addition of mullions further enhances the structural integrity of the windows. When closed and locked, casement windows with mullions offer excellent security, as they are difficult to pry open from the outside.


Casement windows with mullions are an excellent choice for homeowners looking to enhance the beauty, functionality, and energy efficiency of their homes. The combination of casement windows and mullions offers enhanced design, improved energy efficiency, increased natural light, and excellent ventilation. Additionally, easy operation, maintenance, durability, and security make casement windows with mullions a valuable investment. Consider incorporating casement windows with mullions into your home to enjoy these benefits for years to come.

casement windows with mullions


Freedom to dream "truly custom-made"

Doorwin provides one-stop solution for professional windows doors manufacturer and installation. We have been serving customers with our high quality and branded products in United States, Asia and worldwide.


With Doorwin, you can have all of this with a simple move. This is because we believe that the best way to achieve your goals is by working with
our customers to find solutions to their problems.Our team of designers and engineers are dedicated to solving these problems by creating
products that are designed to be easy to install, easy to maintain and repair, while being cost-effective.

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Our team of experts will work with you to develop a bespoke plan that fits your needs. We take a holistic approach to the planning process, combining our technical expertise with our knowledge of customer requirements and project constraints.

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Doorwin is the manufacturer of full custom fenestration systems, and we're here for you. We provide you with the freedom to design your windows, doors, and more with no additional charge for special shapes, hardware styles, and color choices. Your vision is our inspiration; our job is to make it a reality.
Our products are made to pass your local inspector's verification and are built under USA building codes so you can rest assured that they are safe and sturdy. Choose Doorwin to experience the best bespoke fenestration service available today!

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We take care of the entire process for you, from beginning to end. We have our own expertise and will provide free-charge design development & contract documentation with CAD and BIM drawings. In addition to elevation details and installation design, we will double-check that the products match the drawings and project specifications through video or pictures. We'll help you specify the delivery schedule and logistics service whilst keeping costs to a minimum.

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We're proud to be one of the top exporters of windows and doors to the United States. We pack each window individually and in four layers, and finally into wooden boxes with non-fumigation, and at the same time, there will be a lot of shockproof measures in the container to protect your items. We ensure that your products will arrive at the sites in good condition after long-distance transportation.
Doorwin has been exporting tens of millions of dollars of windows and doors to the U.S. every year, and we know that improper packaging can cause breakage of the product when it arrives on site. What the client concerns, we concern most.


Doorwin experts are experienced in working with architects, builders and homeowners to ensre your vision becomes a reality.Welcome to visit a showroom, ask questions about product pricing, request a quote and more.

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What Projects Can We Take?

We are tested by the following standards:
-NFRC (North American Fenestration Rating Council)
-AAMA (American Architectural Manufacturers Association)
-WNMA (Wood National Monument Association)
-CSA101 (Canadian Standards Association)
-I.S.2 (International Standard ISO/IEC 17025)
-A440-11 (Standard for Fire Testing of Door Assemblies for Charging Rooms)


Doorwin is a company that specializes in custom-made doors and windows. We understand that every home is unique, and we are committed to providing you with the highest quality products possible.Our products are inspired by different lifestyles, and we respect your vision when designing them. Our designs are made specifically for you, so there is no additional cost. We work across styles and profiles, whether you're remodeling an old house or designing your new dream home. Find inspirations here and we will fulfill all your imaginations.