Buyer's guide - everything you need to know before you pick a bifold
A bifold door is a big decision. It is often the biggest single item of glass in your home. It shapes the way a room feels every day. So it is worth taking a few minutes to understand the choices. Below is a plain-English guide to what matters, what to ask, and what to avoid.
How a bifold door works
A bifold door is a set of slim door leaves that fold back on themselves. Each leaf hangs from a top track and slides on hidden rollers. When you push the handle, the leaves concertina tight against the wall. You are left with a clear opening. The more leaves you choose, the wider the opening can be. A three-leaf bifold can go up to about 3.5 metres wide. A six-leaf bifold can reach 6 metres or more.
Aluminium or uPVC?
We only recommend aluminium for a bifold. uPVC bifolds exist but the frame has to be much thicker to carry the weight of the glass. That means less light, a less modern look, and they tend to sag after a few years. Aluminium is stronger by weight so the frames can be slim. Aluminium also does not warp in heat, does not go brittle in cold, and does not yellow in the sun. Our bifolds use a thermal break inside the frame so the outside cold never meets the inside warmth. That is why the U-value stays low even on large spans.
How many leaves?
Three leaves is the most common choice for a 3 to 3.5 metre opening. Four leaves suits 3.5 to 5 metres. Five and six leaves are for large rear elevations on 5 to 6 metre extensions. If you want to walk through the door every day without folding the whole thing, pick an odd number of leaves. One leaf can then act as a normal door with a single handle. We call this a "traffic leaf".
What is a flush threshold?
A flush threshold is a very low aluminium track at the bottom of the doors. The floor on each side sits at the same height. It looks amazing and works brilliantly for level-access buildings. A weathered threshold is a slightly higher track that sheds rain more aggressively. For most domestic builds we fit a low-profile weathered threshold. For ground-floor rear extensions with a continuous floor finish we fit flush. Both are fine under Part M of Building Regulations.
Thermal performance - what the numbers mean
U-value measures how much heat escapes through the door. The lower the number, the better the insulation. Part L requires 1.4 W/m²K or better on new and replacement doors. Our Versatali bifolds come in at 1.2 W/m²K on standard double glazing and 0.8 W/m²K on triple glazing. That beats the Part L minimum by a comfortable margin and is better than many composite front doors. If you plan to heat the extension in winter, ask for the triple-glazed option. The upgrade pays back in reduced heating use within a few winters.
Security
Bifolds get a bad rap on security because of cheap imports. Our Versatali is PAS 24 tested - the British break-in standard. Every door has shoot-bolts top and bottom on every leaf, hook bolts on the main traffic leaf, anti-lift rollers, internal beading, and a TS007 3-star anti-snap cylinder. It is the same security package as our aluminium front doors. That matters when this is the only glass door between your family and the garden at night.
Supply only or supply and fit?
We do both. Supply-only is popular with builders and installers. You get a trade price, a full technical pack and phone support on the install day. Supply and fit is popular with homeowners. Our in-house installation team handles the measure, the fit, the sign-off and the aftercare. Either way you get the same 10-year guarantee on the hardware and the frames.
How long does it take?
From the day we confirm your order, standard lead time is 4 to 6 weeks for the doors to arrive. Supply-only can be quicker. Supply and fit adds a fitting day at the end of the build. Priority service can bring this down to 2 to 3 weeks - tick the priority box on the quote form if your site needs it.
What do we include?
Every Versatali order comes with the pre-assembled frame, the doors, the handle, the lock cylinder, the keep plates, the threshold, the weather gaskets, the trickle vents (where required) and the fitting guide. You do not need to chase extras. A builder who has fitted one of our bifolds before can normally have a fresh set installed in a day.
How to get a quote
Use the form at the top of this page. Tell us if you know the exact size or just an approximate width. Send a photo on WhatsApp if it is easier. We come back with a written quote within 24 working hours. If you need a site visit we will book a time that suits you, and our visits are free with no sales pressure - we will measure, talk options and leave you to decide.
Engineering detail - what makes Versatali different
Our Versatali bifolds are built on an advanced 80 mm aluminium system designed to give slimmer sightlines, larger glass panels and faster fabrication. The corner mould uses increased compression and a three-gasket interlock - the reason we can publish a 0.9 W/m²K triple-glazed U-value without resorting to foam fillers. Foam breaks down inside the profile over time; bonded polyamide and compressed gaskets do not. It is the quiet reason your bifold will still weather-seal in year twenty the way it did on install day.
The leaves use a half-roller design that removes the need for a floating mullion. When the doors are parked back you get a clean, uninterrupted sightline straight through the opening. Each roller is engineered for 130 kg per panel, so a tall 2.4 m sash opens with one finger and glides the whole travel without snagging. A captive top guide and positioning rail keep the geometry safe on high doors and make install easier - a single builder can square the opening, drop in the frame and hang a full set of leaves in an afternoon.
Technical specification at a glance
System depth 80 mm. Double-glazed U-value 1.3 W/m²K. Triple-glazed U-value 0.9 W/m²K. Air permeability Class 4 to 600 Pa. Water tightness Class 5a to 200 Pa. Wind resistance Class C3 to 1200 Pa. Security PAS 24. Cycle testing 50,000 cycles (primary leaf), 5,000 cycles (secondary) to BS 6375. Maximum leaf height 2400 mm standard, 3000 mm optional. Maximum leaf width 1200 mm. Maximum vent weight 130 kg. Glazing 24 mm to 46 mm clip-bead. Sightline at head 80 mm (slim), interlock 87 mm. Available in single colour, dual colour, textured and anodised finishes. Low 30.7 mm aluminium threshold option for Part M level access when fitted into floor level. These are the numbers your Building Control officer and your architect will want on the spec sheet - ask us for the full data sheet with your quote.
Configurations - over 17 to choose from
The Versatali system is truly scalable. You can build a bifold in more than seventeen leaf and opening configurations, and you can continue the same design language across single doors and double doors for total consistency around the property. That means the back-garden bifold, the side-return single door and the front utility-room door can all share the same slim frame, the same handle family and the same colour. We can design a matching single traffic door next to a huge seven-leaf bifold so the rear elevation reads as one continuous glass wall.
