Patio Doors near you

The honest question is how you will use the opening day to day. Bi-folds give the largest clear opening and the best summer moment, but on the many British days when the doors stay shut you are looking at more frames than glass, because every panel carries a stile. Sliding doors reverse that: the view when closed is better because there are fewer vertical bars, and roughly half the opening is the most you can ever clear. French doors open fully in a second, which is why they win on a door used several times a day to reach a bin, a shed or a washing line.

Width usually settles it before taste does. A narrow rear opening in a terrace rarely justifies a bi-fold, because once each panel is wide enough to walk through there are only two or three of them and the stacking eats the reveal. A wide opening in an extension is the opposite case. Swing space matters too: French doors opening outwards need clear paving and no pot, planter or table in the arc, and French doors opening inwards need floor space that a small kitchen may not have.

Then there is the maintenance profile, which differs more than the brochures admit. Sliding and bi-fold doors depend on rollers, guides and a track that has to be kept clear; hinged French doors depend on hinges, keeps and a weatherseal. A track full of grit from a British garden is the single most common reason a sliding door becomes hard to move, and it is a cleaning problem before it is a hardware problem.

A patio door is a critical location almost from end to end. The Planning Portal identifies the areas needing safety glazing as any panel up to 800mm from floor level, within any glazed door up to 1500mm from floor level, and any side panel to a door within 300mm of the door edge up to 1500mm from floor level. Since a patio door leaf is glazed from close to the floor upwards, the whole lower two-thirds of every panel sits inside the rule, and the fixed screens beside French doors usually do too.

Approved Document K sets out what satisfies requirement K4. In a critical location you comply by ensuring glazing breaks safely, by choosing glazing that is robust or in small panes, or by permanently protecting it. Safe breakage is defined by test in section 4 of BS EN 12600 and clause 5.3 of BS 6206, and a glazing material suits a critical location if it meets Class 3 of BS EN 12600 or Class C of BS 6206 — relaxed to Class 2 or Class B where the pane is in a door or door side panel and its width exceeds 900mm, which most patio door panes do. The document explains the reasoning in terms anyone with children will recognise: an initial impact between waist and shoulder level can be followed by a fall through the glazing.

On planning, the default is permissive. The Planning Portal states that you do not usually need to apply for planning permission for the insertion of new windows and doors of a similar appearance to those used in the construction of the house, and notes separately that a new bay window will be treated as an extension and may require permission. The exceptions are the ones to check before ordering: a council may have made an Article 4 Direction withdrawing permitted development rights, a leaseholder may need permission from a landlord or management company, a listed building needs listed building consent for any significant works internal or external, and a conservation area, national park or area of outstanding natural beauty may carry additional restrictions.

On building regulations, a patio door is controlled work. GOV.UK lists replacing windows and doors among alteration projects that might need approval, and its exemption for external doors is limited to those where less than half of the door is glazed — which excludes every patio door. The straightforward route is an installer registered with a competent person scheme: GOV.UK's authorised list covers replacement windows, doors, roof windows or rooflights in existing dwellings through Blue Flame Certification, CERTASS, Certsure, Fensa, NAPIT and ASSURE. The alternative is an application to a building control body, either your local authority's building control department or a private registered building control approver.

Three Approved Documents then apply at once. Approved Document L treats the entire unit including the frame as a controlled fitting, expecting it to be draught-proofed and to meet the limiting standards in Table 4.2, where a door with more than 60% of its internal face glazed is held to 1.4 W/(m²K) or a Doorset Energy Rating of Band C minimum. Approved Document K covers the glazing and any guarding. Approved Document F requires that where building work such as replacing a window or door affects ventilation, the dwelling's ventilation either meets the standards or is not less satisfactory than before the work was carried out.

The threshold is where a patio door succeeds or fails. A high weathered cill sheds water well and trips people; a flat threshold is easy to cross and asks much more of the drainage detail beneath it. British driving rain makes this a real trade-off rather than a styling choice, particularly on an exposed elevation or where a patio slopes back towards the house.

Approved Document M is the reference point for what a level threshold should achieve, even though its provisions bite on new dwellings rather than on a replacement in an existing one. For the principal private entrance to a dwelling it expects a minimum clear opening width of 775mm, any threshold to be an accessible threshold, and, where a step into the dwelling is unavoidable, a rise of no more than 150mm aligned with the outside face of the door threshold. If someone in your household uses a wheelchair or a walking frame, those numbers give you something concrete to specify rather than a vague request for a low threshold.

A glazed door at an upper floor, or above any change of level, engages requirement K2 as well as K4. K2 asks that stairs, ramps, floors and balconies, and any roof to which people have access, be provided with barriers where it is necessary to protect people from falling. Approved Document K's guarding table for single family dwellings sets 900mm for stairs, landings, ramps and the edges of internal floors, and 1100mm for external balconies including Juliette balconies and the edges of a roof. That 1100mm figure is the one that governs the Juliette arrangement people fit behind French doors on a first floor.

Where the glazing itself is doing the containing, the same table gives a height below 800mm for glazing at changes of level provided to give containment, and 800mm at opening windows other than roof windows in loft extensions. In other words a glazed panel can be part of the guarding solution, but only if it is designed for that job — it is not something to assume because the glass looks substantial.

Children get a specific rule. In a building that may be used by children under five during normal use, Approved Document K expects guarding to be built so that a 100mm sphere cannot pass through any openings in it, and so that children cannot readily climb it, which means avoiding horizontal rails. If you are fitting a Juliette balcony or any guarding behind a patio door in a family home, raise both points with the installer at quotation stage, because a design that fails either one is difficult to correct after installation.