Bi-fold doors are the door of choice for opening out to patios and gardens, but can the modern look of a bi-fold door ruin the character of older (or period-style new build) homes? Natasha Brinsmead investigates

These days no contemporary home seems to be complete without a swathe of bi-fold doors capable of opening up vast spaces to the outdoors and blurring the boundaries between garden and home. There is no doubt that they are visually impressive and that they add a whole new element to the way in which homeowners use their house — but what about those living in period properties? Can they enjoy all the benefits of bi-fold doors (also known as folding sliding doors) too without spoiling the classic traditional features of their home?

Of course, bi-fold doors were never an original feature of traditional buildings, but with the right forward planning and thoughtful design, they can enhance and fit in with the existing home.

Folding Doors by Architectural Bronze Casements

These sliding doors from Architectural Bronze Casements on a sunroom by Vale, meant no compromise was made to the period style of the original building

Should Bi-Fold Doors Blend In?

Trying to match the new doors to your original windows or existing doors is very tricky. If you are aiming for the new bi-fold doors to blend in with the rest of the building’s original external features, then timber is the obvious way to go. Bear in mind though that it is crucial that you look at the quality of the timber you are opting for first.

Wood has a natural tendency to warp and twist according to temperature and humidity levels, even if you opt for a hardwood. It goes without saying that wood needs to be primed and maintained, but a good-quality engineered cross-laminated timber is a good option with increased stability. It’s worth noting that warping will not only cause the weather systems on the door to fail, but will also impact on how the doors operate.

Albery Georgian Bar doors

These Albery Georgian Bar doors are made from solid engineered oak, supplied pre-finished with an access door for day-to-day use, and the units are top-hung. They cost £2,699 for a three-door unit supplied only at Wickes

If you are aiming for your doors to match multi-paned casement windows, you could run into issues with sightlines as the glazing bars will generally need to be thicker in order to accommodate double or triple glazing. That said, there are companies who will custom make doors for just these situations, such as Original Sash. It’s also worth taking a look at the Sunflex 75H Timber (75mm front-to-back) bi-fold door system from IDSystems, who claim to have the slimmest sightlines in Europe at just 122mm. They also come in a range of stains and paint finishes.

If you are dealing with metal casements, it is quite possible to have doors made with lead glazing bars and decorative leaded lights to match. Although, if you are looking for quality timber frames, as opposed to cheap-looking PVCu look-a-likes, the chances are you will need to have them custom-made, which will add to costs but will be well worth it in the long run.

bi-fold doors are from Ayrton Windows & Doors

These bi-fold doors are from Ayrton Windows & Doors, price on application

Traditional-style Alternatives

You may be are struggling to find a good match for your original windows, or are concerned that attempting to match your original windows with a new door could create a design contradiction. If so, it may be time to accept that opting for a timber that simply complements the rest of the windows and doors on the house could look better than a match that is not really a match at all.

If you are set on an authentic option, French doors are a very good idea. “French doors remain a classic product and suit the period house,” admits Chris Wood of Lomax+Wood. “French doors are architecturally the more aristocratic product for the purist concerned with correct sightlines, as opposed to the more brazen bi-folding door addition to the rear of the house.”

Ayrton Windows & Doors bi-folds

Ayrton Windows & Doors can make bi-folds with either timber or lead glazing bars to suit your home. These doors cost from £4,499

Contrasting Styles

Perhaps an easier option than matching the originals, fitting bi-fold doors that are in complete contrast to the rest of the joinery on your home will obviously mean that they stand out as a new addition, but this is not always a bad thing — providing it is done well.

But, while adding bi-fold doors to a new extension provides the ideal opportunity for choosing doors which are in a contrasting, yet complementary style to the rest of the house, adding them to an existing section of the house can be trickier. A great option is to choose aluminium for the exterior with a timber interior, such as Centor UK’s Series 200 integrated doors. The aluminium exterior can be powder-coated in a colour that matches the rest of your external woodwork, while the warmth of the timber interior will suit most traditional properties well.


One feature that many people seek when installing bi-fold doors is a level threshold. This is where the floor track that the doors run on is flush with the floor and the internal and external floor levels are the same height. To work successfully, the space must remain watertight and so good drainage must be incorporated into the design (try ACO’s DoorWay Drain).

The floor in front of the threshold should slope gently away so that water cannot pool in front of the doors. Alternatively, building up the external floor level with a timber deck gives the appearance of a level threshold without the risk of water ingress.

Made-to-order double-glazed doors from the Kensington & Chelsea range by Lomax+Wood

Made-to-order, these double-glazed doors are from the Kensington & Chelsea range by Lomax+Wood

The Practical Issues

Unlike new builds, period properties tend to have uneven floor levels and door openings which are not of a standard size. Having your doors made to fit will be the only option for many period property owners, not only in terms of getting a style to suit, but in getting doors that fit properly.

Peter Watkins of Centor UK offers these tips for those considering fitting bi-fold doors:

  • Ensure that the door frames are square in three dimensions. It’s important that the cill on the bottom rolling systems is level, and to achieve this, support should be directly under the jambs to avoid unintentional bowing of the cill.
  • Homeowners should ask about adjustment when choosing bi-fold doors as it is variable between manufacturers; the best manufacturers have vertical and lateral adjustment.
  • Be aware of building settlement and take preventative action — this is why height adjustment is so important.
  • The lintel needs to be designed to limit deflection and creep with wide openings. Steel beams are the practical answer for wide openings.
  • Ideally the height of the finished floor level should be as close as practical to the top of the cill. This can be achieved by building up the height of the finished floor or cutting uneven flooring away so that its variable height never goes above cill height.
  • Consideration should also be given on how to cover any exterior gaps on the head and cill.

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