Everything You Need to Know About Bifold Doors – Are They Right for Your Project?

Bifold door materials & finishes

Bifold doors are available in a range of different materials. Aluminium, timber and alu-clad versions are the most prevalent choices, offering a great balance of performance versus cost – although steel and PVCu options are also available. To add a personal touch or match specific design features found in your scheme, many systems can also be finished in bespoke RAL colours or stains.

A Sieger Systems Legacy bifold, is the centrepiece of this house renovation in London. Elegant glazing bars give the system a heritage steel look. A four-panel configuration was chosen, with a three-panel stack and a single action hinged door for quick access to the garden

If you’re upgrading a period property or creating a heritage-inspired new build, consider opting for plant-on glazing bars to complement the architecture. “Glazing bars can offer a lovely feature for more traditional homes,” says Rebecca, “and since they’re added retrospectively, they don’t create thermal breaks in the panes.”

Aluminum bifold doors

Aluminium is a go-to choice for bifold doors, as its inherent strength enables the slimmest sightlines. It’s also very low maintenance – although there will always be some upkeep required. “Aluminium bifold door frames tend to require some silicone spray to the hardware and regular checks and cleaning of the tracks to make sure you remove any debris that could potentially damage the mechanism,” says Joanna Smith, marketing manager at Grabex Windows.

This project in Richmond, by Grabex Windows, features an entire wall of bifolds, spanning 9.2m across and 2.8m in height. It comes with a master door in the middle for easy access, flush threshold  and two matching picture windows in the corner to maximise natural light

Composite bifold doors

Composite bifold door systems offer a mix of materials, providing you with the warmth of wood alongside the sleek, modern appearance of metal. This style of bifold door is typically made from engineered timber, with an aluminium shell mounted to the exterior surface. The wood finish is left exposed inside and stained or painted to your preference.

Timber bifold doors

Fully-timber bifolds deliver bags of character and very good thermal efficiency. However, they will require periodic reapplication of stains and coatings when being used externally, in order to help maintain their appearance and performance in the long term.

How long are the lead times for bifold doors?

Lead times for bifold doors can vary hugely based on what material, size, colour, thermal properties and service you specify. As with most glazing products, the more custom your design, the longer it will take to produce your system. Supply-and-install services are a handy option for homeowners, as it means there is only one point of contact responsible for the finished result.

“Generally, for a supply-only set of timber bifolds, the lead time can be as short as three or four weeks, but if installation is required, it’s usually eight to 10 weeks,” says Matt Higgs, managing director at Kloeber. “Placing your order for bifolds 12-14 weeks before they’re required will give you flexibility to fit in with the project’s schedule.”

It’s a good idea to ask a glazing supplier to look over your plans as early as possible, so they can start providing advice on viability, starting prices and tweaks that could enhance the finished bifold door install. This way, as your plan develops, you will benefit from a good understanding of what the supplier can offer you in terms of materials, costs and lead times – as well as guidance on technical issues, such as where the frame should sit within the thermal envelope, cladding returns and other considerations.

How much do bifold doors cost?

Generally, bifold doors cost more than sliding patio doors, largely because of the extra hardware and additional profiles. “A good quality bifold system could start at £1,000 +VAT per panel,” says Matt. It won’t come as any surprise that the more bespoke you go, the more the bifold doors will cost. “An airtight, three-leaf, 2,400mm x 2,100mm Lacuna bifold door starts at £4,995 +VAT and installation,” says Morten Wendt, director at Lacuna. Wider expanses of glass with fewer breaks will cost considerably more than modestly partitioned bifolds, for instance, while the fact alu-clad systems use two materials will always put them at the premium end.

The Sunflex SF75 eco bifolds won the 2023 Build It Award for Best Glazed Doors thanks to the system’s outstanding thermal performance

If you’re keen to achieve the best possible thermal performance, you’ll want to invest in a quality set of bifolding doors that is specified to match your expectations. “For those who are seeking ultra energy-efficient doors and decide to go for triple glazing rather than double, you will find the bifold doors cost more,” says Edward Stobart, technical sales manager at IDSystems. “Any upgrades to the hardware and insulation to meet Passivhaus standards will also cause an uplift in price,” says Joanna.

guide to bifold door costs

Are bifold door systems energy efficient?

A glazing system’s ability to retain heat and resist thermal energy transfer is quantified through its U-value rating. The lower this number, the better the product’s insulation properties and the more heat it will keep inside your home. Good gas-filled double glazing will easily meet Building Regs, with triple-glazed doors capable of achieving Passivhaus standards of efficiency.

But, it’s not just the glass that impacts heat transfer and the efficiency of the bifold doors. “Nowadays, the majority of heat loss is through the frames,” says Edward. “So, look for a bifolding system with an advanced multi-chamber thermal break to prevent cold bridging.”

Timber bifolds, like this one by Lacuna, add warmth and rustic charm to a space. While they can be used as external doors, here a run has been installed internally to create a flexible, broken-plan space

If you’re installing bifolds in an existing house, they’ll almost certainly need trickle vents to meet Building Regulations related to air quality. The big downside of this is that you’re essentially putting holes through your wall that will allow heat to leak out. In a new build or whole-house retrofit, you can control this aspect with mechanical ventilation and heat recovery (MVHR), negating the need for trickle vents.

How do I know if bifolds are right for me? 

If space is an issue or you have budget constraints, bifolds might not be the most suitable choice for you. “If you don’t have ample room, a French door can perform a similar job at a much cheaper cost,” explains Morten. Indeed, for smaller apertures, French doors can deliver more-or-less the same level of access as a bifold and don’t need to be fully opened to allow you to pass through.

Once you go beyond the typical width a set of French doors can manage and assuming you have sufficient internal or external space to house the stacked doors, bifold doors become a go-to choice to create expansive openings that connect inside and out in a way you can’t get with other products on the market.