Castle Windows install Sheerline bifold doors in homes across Newbury, Reading, Basingstoke and Berkshire. Start an aluminium bi-fold door quote today or read more about this product below.
Sheerline bi-fold doors redefine how you connect your indoor and outdoor spaces. Designed with cutting-edge aluminium frames, these doors combine elegance, strength, and thermal efficiency. Whether you want to maximise natural light or create an open-plan living area, Sheerline bi-fold doors are the ultimate choice for modern homes.

Low Thresholds
Smart Quality
Glazing Options

Prestige bi-folds can help soften boundaries, creating an increased sense of space and a seamless transition between your garden and the inside of your home.
Slim, elegant, aluminium ensure light bathes interiors, even when doors are closed. Giving you bright airy interiors no matter what style or configuration of Prestige bi-fold you choose.
Clean, crisp lines on the outside hide away our innovative Thermlock® multi-chamber thermal design, helping keep you and your property well insulated against the worst of the UK weather. Their insulating chambers act as a thermal break and work in conjunction with high performance glazing to create class leading thermal performance, far superior to traditional polyamide thermal breaks.
Custom designed single rollers eliminate the need for floating mullions. Ensuring that whatever your style of door, our bi-folds have consistent 138mm sightlines between sashes, creating our trademark balanced look.
With 5-point locking and double deadbolts, every element of the Prestige bi-fold has been designed to keep you and your home secure. We also use full length security interlocks on appropriate styles to protect your home from would-be intruders. These bind the sashes tightly together if attacked.
French passive doors include an integral finger pull lock, eliminating the need for a second handle – continuing the clean, minimal Sheerline aesthetic. An innovative mishandling device also ensures doors are locked in the correct order.
Configurations
Up to seven panes wide in a variety of styles. Depending on the layout of your space, you can have your doors split left and right or slide to one side. Consider adding a single ‘traffic’ door to your arrangement as a terrific approach to provide a daily entrance for when the weather is bad. Also available in single and French doors.

Experienced Home Improvement Specialists
When investing in a modern home improvement product such as bifold doors, you want to ensure that you’re working with the best installers in the area. Here at Castle Windows, we boast over 30 years of industry experience and have worked with over 40 thousand customers in that time.
With this, we are seasoned veterans to the home improvement game and can be relied upon for professional and efficient installations. Better yet, we are also supported by FENSA, Checkatrade and Master Builder.