Glazed bi-fold and sliding patio doors have grown enormously in popularity over the past 20 years, used in place of French doors with sidelights on traditional as well as contemporary properties. Effectively a wall of glazing, they allow your living space to be bathed in natural light and give unrestricted views of the garden year-round, but in warmer weather, they can also be pulled back to create a ‘third living area’ — an outdoor room with a seamless flow of space inside and out. Installing bi-fold or sliding doors into older homes can be achieved in one of two ways: retrofitting them into existing walls, or adding them as part of a new extension. Replacing original patio or French doors with those of the same size is fairly straightforward and won’t usually require planning permission, provided that the work is classed as permitted development (see planningportal.gov.uk). However, larger frames will require material and structural changes to a property (specifically, widening an existing opening and replacing the supporting lintels) and this work must comply with building regulations.
In terms of design, for those looking to retrofit, there are plenty of styles available to suit traditional homes, from simple glazed frames to those with panes subdivided by vertical and horizontal glazing bars, leaded lights and panelling. Alternatively, many companies offer a bespoke design service to match original glazing. Traditional panelling and glazing bars make these bi-fold doors from Town & Country perfectly suited to period homes. Made from laminated hardwood, a similar six-door set, H296x W596cm, would cost around £10,872 (020 7091 0621) As for extensions, the door should be chosen to suit the architectural style of the new addition, rather than the main house. Extensions are increasingly designed as a complete contrast to the original building, rather than being in keeping, so sleek, contemporary systems with minimal sightlines and slim profiles may be a solution. Material matters There are four main options for frame materials: aluminium, timber, uPVC and composite.
Durable, low-maintenance and strong enough to allow very minimal frame dimensions, aluminium is the most suited to bi-fold and sliding doors, and can be finished in a wide range of colours using a low-maintenance powder-coating process. With solid oak laminate frames, the Albery Georgian bar bi-folds from Wickes combine classic styling with affordability and practicality. Priced £4,599 for a six-door set, H209xW419cm, they are supplied with pre-drilled holes for quick and easy installation (0330 123 4123) For those wanting a traditional look, solid timber is probably the best option, but it is prone to twisting and warping and will require maintenance – for a similar, but more hardwearing and affordable look, the answer may be engineered or cross-laminated timber. Another low-maintenance alternative to wood doors is composite, in which timber frames are clad externally in powder-coated aluminum — giving a weatherproof exterior, but an attractive natural wood finish to your traditional interior.
While it has some desirable properties, uPVC should generally be avoided in character period homes. These timber bi-fold doors from Architectural Bronze Casements, from £6,500 for a H230xW360cm set, feature bronze casement inserts with applied lead detailing (0845 600 0660) Practicalities There are other things to consider before buying your doors: from the configuration and glazing to the supplier and security. The system you need will depend on the span of the opening. Standard bi-fold door options range from two-door to eight-door configurations, but corner, bay window and larger bespoke solutions are available. Your supplier will be able to advise on the right system and design for your home. For a robust country look, Vufold’s Prestige three-panel bi-folds, H209xW179cm, have engineered solid European oak frames, and cost £1,989 (01625 442899) External patio doors are usually supplied double-glazed with toughened safety glass as standard. High-performance coatings or triple glazing can be used for better thermal efficiency.
As with any external door, security is paramount, so choosing a multipoint lock system, with hooked locking points and shoot bolts, is recommended. XP Glide Light aluminium sliding doors are Express Bi-folding Doors’ slimmest sliding solution and look the part in this modern extension to a period property. Measuring H210xW430cm, these cost around £4,000, including installation (0800 121 4809) Made bespoke to fit a barn conversion, these hardwood sliding door sets by Arbor Bifold are finished in a shade of microporous paint to match existing windows — a condition of planning permission. A similar H210x W240cm door set would cost around £3,720 (01454 270039) The Kensington & Chelsea bi-fold doors from Lomax & Wood are made from sustainably sourced engineered timber and are supplied finished in three coats of high-quality durable microporous paint or stain. They are made bespoke in several designs, including with classic glazing bars, as shown. From £1,080 per H200xW90cm panel (01277 353857)
Pictured retrofitted into an older property, Everest’s bi-fold aluminium doors come in six frame colours, with seven panel options and a range of glazing. Doors are made bespoke and priced from £4,200 for a five-panel system measuring H220x W410cm (0800 008 7140)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? 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.
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 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. 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.
These bi-fold doors are from Ayrton Windows & Doors, price on application 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 can make bi-folds with either timber or lead glazing bars to suit your home. These doors cost from £4,499 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.