Balcony / terrace doors

What Is the Difference Between HST Sliding Doors and PSK Sliding Doors?

When planning the appearance and functionality of a home, sliding door systems are often a top consideration. They offer numerous advantages for residential and commercial spaces alike, including increased natural daylight, unobstructed outdoor views, and easy access to terraces or balconies.

Although sliding doors are widely regarded as a worthwhile investment that can enhance property value, not every system delivers the same level of comfort or reliability. Knowing how HST and PSK sliding doors differ will make it easier to choose the most suitable solution for your needs.

Sliding door systems are an innovative development in modern window design, driven by architects’ demand for large glass surfaces. They make it possible to install expansive glazing while maintaining smooth operation, contemporary aesthetics, and visual elegance. Sliding doors are ideal for bringing more daylight into your home and visually connecting indoor and outdoor spaces. Since the panels slide rather than swing open, they do not require additional clearance, making them practical even in smaller interiors. Among the available options, PSK and HST are the two most commonly used systems, each offering distinct features and benefits.

PSK sliding doors are designed to support wide glazed panels, with individual sashes reaching up to approximately 1.6 meters. These large glass areas allow plenty of natural light and help create a bright, open atmosphere, which is why PSK systems are frequently chosen for both modern and classic homes. Their operating principle is unique: when closed, the panels sit flush in one plane, but to open them, the sash must first tilt inward before sliding along the track. Because the tracks are mounted at both the top and bottom, installing a low or flush threshold is not possible. This can pose a challenge for seniors or people with limited mobility. Additionally, due to the size and weight of the sashes, the tilt-and-slide mechanism—similar to that of standard tilt-and-turn windows—may be less smooth and more susceptible to operational wear over time.

The HST sliding door system uses a lift-and-slide mechanism, where the sash is slightly raised before being moved. This solution is extremely flexible and works well in both traditional and contemporary architectural designs. Each panel runs on its own dedicated track, allowing for various combinations of fixed and movable sections. Unlike PSK doors, HST systems can be installed with a flush, floor-level threshold, ensuring easy, step-free access to outdoor areas such as patios, gardens, or balconies. Lift-and-slide doors can also accommodate significantly larger panels than tilt-and-slide systems. A single HST sash may reach widths of up to 3 meters, providing a clear opening of nearly 2.9 meters. By combining two sliding panels, it is possible to create openings close to 6 meters wide. One of the most distinctive advantages of the HST system is the option to create 90-degree corner openings, which dramatically enhance both interior flow and exterior design. Overall, HST lift-and-slide doors are considered the most functional and efficient solution for openings wider than 2.5 meters.