Bifold doors cost: what decides bifold and patio door prices

Opening width and the number of panes

Width is the biggest single factor. A bifold door is made of several narrow leaves that fold back against each other, so a wider opening needs more leaves, more hinges, more rollers and more locking points. Each extra leaf adds to the cost.

A sliding patio door covers the same width with fewer, larger panes, usually two or three. Fewer panes means fewer moving parts, which is one reason sliding doors are often cheaper for a given opening.

Frame material

The frame material changes both price and look. uPVC is the most affordable and performs well thermally. Heavier, larger panes need a stiffer frame, so very wide bifolds and big sliding panes put more demand on the profile. Colour also matters: white is the standard, while solid colours, woodgrain foils and dual colour frames cost more than plain white.

Glazing specification

Bifold and patio doors are mostly glass, so the glazing spec has a bigger effect on price than it does on a front door. Larger panes cost more to make and handle, and every pane must be safety glass. Upgrades such as laminated glass for security, better energy ratings or solar control glass on a south-facing elevation all add cost but can be worth it on a big glazed wall.

• Pane size: larger units cost more to make and fit
• Toughened or laminated safety glass
• Energy rating and coatings
• Solar control glass for sunny elevations

Threshold type

The threshold is the bottom track the door runs on or closes against. A standard raised threshold gives the best weather protection. A low threshold makes stepping in and out easier and suits wheelchair access or a level patio, but it needs careful drainage and finishing outside. Low thresholds add to the cost and can add groundwork.

Building work to widen an opening

Replacing an existing patio door in the same opening is the simplest job. Turning a window into a door, or widening an opening for a bigger bifold, means structural work: a new or longer lintel, cutting brickwork and often a structural engineer's input. That work can cost as much as the doors themselves, so plan for it early.

Widening an opening is also likely to need Building Regulations approval for the structural change. We look at the opening at survey and tell you plainly whether your plan is a straight swap or needs building work first.

Removal and making good

A fitted price should include taking out the old door or window and frame, disposing of it, fitting and sealing the new door, and making good the plaster, render or brickwork around it. On a wide opening there is more reveal to finish, so check what a quote includes before comparing totals.

Sliding patio or bifold: which is better value

A sliding patio door is usually the better value when you want a wide view and plenty of light but rarely open the whole wall. Its large panes give slimmer sightlines and fewer frames across the glass, and there are fewer moving parts to wear.

A bifold is the better choice when you want to open the whole opening to the garden in summer and are happy to pay for the extra leaves. It suits kitchens and extensions that lead straight onto a patio. Where the opening is narrow, French doors can be a simpler option again.