Are Bifold Doors Right for Your Home? A Complete Guide

Bifold doors have become one of the most popular home improvements in the UK, and for good reason. When open, they concertina neatly to one side, opening up to 90% of the aperture and creating a seamless connection between your home and garden.

But they’re a significant investment, and there are important decisions to get right – material, configuration, threshold type, security specification and whether bifolds are actually the best option for your space. Here’s what you need to know.

Bifold Door Materials: Aluminium vs uPVC

Aluminium

Around 70% of bifold doors sold in the UK are aluminium, and it’s easy to see why. Aluminium offers the slimmest sightlines (some as narrow as 36mm), maximising the glass area and the views. It’s strong, lightweight, available in over 150 RAL colours, and lasts 30-40+ years. Thermally broken aluminium achieves U-values of 1.3-1.6 W/m²K for standard double glazing.

uPVC

uPVC bifolds are the most affordable option with excellent thermal performance (0.9-1.4 W/m²K). Frames are chunkier than aluminium, and panel sizes are more limited. They suit properties where matching existing uPVC windows is important.

Configurations and the Traffic Door

Bifold doors come in various configurations – 2+1, 3+0 (all panels one direction), 2+2 (centre opening), 3+1, 4+1 and more. The numbers refer to how many panels fold to each side.

A traffic door (sometimes called an access door) is strongly recommended if the bifolds are your only garden access. This is a single panel that opens independently like a regular door, so you don’t need to fold the entire set every time you pop outside. It adds slightly to the cost but makes daily life much more practical.

Threshold Options

Standard threshold (50-70mm): Best weather performance. Recommended for most UK installations, especially exposed or coastal sites.

Low threshold (15-24mm): A good balance between accessibility and weather sealing. Meets Part M of the Building Regulations (≤15mm for new dwellings).

Flush threshold (~0mm): Seamless indoor-outdoor transition. Looks beautiful but requires careful drainage design to prevent water ingress. Not ideal for weather-exposed locations.

Security

Good bifold doors are more secure than people assume. Look for:

• PAS 24:2022 certification (the current UK security standard for doors)
• Multi-point locking with shoot bolts top and bottom
• Internally beaded glazing (glass can’t be removed from outside)
• Laminated glass (required for PAS 24 compliance – it holds together if smashed)

Bifold doors from reputable manufacturers meet these requirements as standard. Budget products may not – always check the certification.

Bifold vs Sliding Patio Doors

This is one of the most common questions we get, and there’s no universal right answer – it depends on your priorities.

Choose bifolds if: You want maximum opening (90% vs 50-66% for sliders), you entertain outdoors frequently, or you want a flexible traffic door option.

Choose sliding patio doors if: You prioritise unobstructed views when closed (sliders have fewer frames), you want the largest possible individual glass panels (up to 3m+ wide), or you prefer a cleaner, more minimal aesthetic.

Planning Permission and Building Regulations

Replacing an existing door with bifolds of the same size generally falls under permitted development. However, you’ll likely need planning permission if you’re creating a new opening, significantly widening an existing one, altering a listed building, or your property is in a conservation area.

Regardless of planning, Building Regulations apply. Your bifold doors must meet Part L (energy – U-value ≤1.4 W/m²K for replacements), Part F (ventilation), Part K (safety glazing) and Part Q (security for new dwellings). A FENSA-registered installer handles all of this as standard.

Frequently Asked Questions

How long do bifold doors last?

Aluminium bifolds typically last 30-40+ years. uPVC 15-25 years. Hardware (hinges, rollers, locks) may need replacement sooner – budget for a service every 5-10 years to keep everything running smoothly.

Do bifold doors let in draughts?

Quality bifolds with proper weather seals perform just as well as any other door type. Budget products with poor seals are a different story. Check the BS 6375 weather classification – look for Class 7A or better for water tightness.

Can I have bifold doors on an upper floor?

Yes, typically opening onto a Juliet balcony. You’ll need a glass or metal balustrade meeting Building Regulations Part K (minimum 1,100mm high). This is a stunning feature for bedrooms overlooking gardens.

See Bifold Doors in Person

Bifold doors are one of those products that genuinely benefit from being seen and operated in person. Visit our showroom in Dunston to see different configurations, compare materials, and get a feel for how they work. Or contact us for a free home consultation.