Glazed bi-fold and sliding patio doors have grown enormously in popularity over the past 20 years, on traditional as well as contemporary properties.
Effectively a wall of glazing, bi–fold doors allow your living space to be bathed in natural light and give unrestricted views of the garden year-round. 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.
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.
There are four main options for frame materials:
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.
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.
While it has some desirable properties, uPVC should generally be avoided in character period homes.
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.
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.
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.
Take a look at a selection of beautiful extensions to period homes, many of which incorporate bi-fold or sliding doors
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.
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 and sound proofing. As with any external door, security is paramount, so choosing a multipoint lock system, with hooked locking points and shoot bolts, is recommended.