A supply-only aluminium door can be an excellent route to a premium extension or renovation – but only when the specification, survey and installation responsibilities are clear from the outset. Knowing how to order supply only doors means more than choosing a frame colour and panel count. You are commissioning a made-to-measure glazed product that must fit the structural opening, meet the needs of the room and arrive ready for a competent installation.
Supply only suits experienced builders, installers, self-builders and homeowners who already have a trusted fitting team. It gives you greater control over the product choice and can simplify a wider building programme. The trade-off is that the installer is normally responsible for checking site dimensions, preparing the opening and fitting the system correctly. A manufacturing issue and a site-measurement issue are very different things, so getting the order information right protects your programme and budget.
Start With the Right Door System
The first decision is whether bifold or sliding doors best suit the opening and the way you plan to use it. Bifold doors fold back to create a wide, open connection to the garden or terrace. They are a strong choice where the ability to open most of the aperture matters more than the narrowest possible sightlines.
Sliding patio doors keep fixed and moving panels within the opening, providing broad glass areas and clean views even when closed. They are often preferred for larger openings, contemporary extensions and rooms where everyday light is the priority. The amount of opening available depends on the panel layout, so this should be considered early rather than after the structure is built.
System choice affects appearance, performance, maximum panel sizes and cost. For example, Smarts Visofold 1000 Bifold Doors offer a proven aluminium bifold option, while Schuco ASFD75 Bifold Doors and Cortizo Bifold Plus may be selected for particular sightline, thermal or design requirements. For sliding applications, the Smarts Visoglide Plus sliding door, Schuco ASE80 Sliding Door and Cortizo COR Vision Plus Sliding Door each serve different project briefs.
Do not select by brand name alone. Ask for a comparison based on your exact width, height, configuration, glass specification and desired finish. A system that is ideal for a modest three-panel opening may not be the best value or best-performing choice for a wide, multi-panel garden elevation.
How to Order Supply Only Doors: Measure the Opening Properly
Made-to-measure doors are manufactured from the dimensions approved at order stage. That makes the survey the most important part of a supply-only purchase. Ideally, the final measurement should be taken after the structural opening is complete, lintels and steels are in place, and the finished floor level is known.
Measure the structural opening in at least three places across the width and height. Check that the aperture is square by measuring diagonals, and identify any bowing in blockwork, steelwork or timber. The smallest relevant dimensions, rather than the most generous, usually govern what can safely be accommodated. Your fabricator or supplier will apply the necessary fitting tolerances, but those tolerances are not there to correct a poorly formed opening.
Finished floor level deserves particular attention. The threshold position affects step height, weathering and accessibility, as well as the internal and external floor build-ups. Tell the supplier whether the measurement is from the structural slab, screed, finished tiles, engineered timber or another final floor finish. If external paving will be laid later, confirm its intended level too. Incorrect threshold information can leave a door sitting too high, too low or without adequate weather protection.
For complex openings, including structural steel above the frame, corner configurations or large sliding panels, a professional site survey is a sensible investment. An installer who will carry out the work should normally sign off the dimensions and build-up details before the order is released.
Confirm the Opening Direction and Configuration
A door can be correctly sized yet still be wrong for the room if the opening arrangement has not been agreed. With bifolds, establish which panel is the traffic door, where the doors stack when open and whether they fold internally or externally. Consider furniture, kitchen islands, garden paths and the natural route from the house to the outside.
For sliding doors, confirm which panels move and where they stack. A two-panel slider may open on the left or right, while a three-panel design can have one moving panel, two moving panels or a central opening arrangement. Look at the drawing from both inside and outside before approving it. Terms such as left-hand opening can be interpreted differently unless the viewing direction is clearly stated.
Include the following information in the order discussion: overall opening size, frame depth where relevant, configuration, internal and external views, threshold type, finish, glazing and handle location. A clear order drawing is not paperwork for paperwork’s sake. It is the final check that the intended product is being manufactured.
Specify Glass for Thermal Comfort and Safety
The glass area of an aluminium door is substantial, so glazing specification has a major influence on warmth, solar control, privacy and safety. Thermally broken aluminium frames combined with energy-efficient sealed units can deliver strong thermal performance, but the final result depends on the whole door specification rather than the frame alone.
Standard low-emissivity double glazing is suitable for many projects. Triple glazing may improve thermal performance in the right system, although it adds weight and can affect panel-size limits, hardware choices and cost. It is not automatically the best option for every opening. A south- or west-facing extension with large areas of glass may also benefit from solar-control glass to reduce excessive heat gain and glare.
Safety glazing should be specified where required, particularly in critical locations near floor level, doors and low-level side panels. Obscure glass, laminated glass and acoustic upgrades may be appropriate depending on the room and location. If the property is exposed, discuss whether enhanced security glazing or hardware options are suitable for the project.
Ask for the overall thermal figures and the glazing build-up rather than relying on general statements about a product range. This is particularly valuable where Building Regulations calculations, a planning condition or an architect’s specification set a defined performance target.
Choose Thresholds, Colours and Hardware Early
The threshold is a practical decision with visual consequences. A standard weathered threshold generally provides the most dependable protection against wind-driven rain. A low threshold can improve accessibility and create a neater transition to a patio, but it needs careful detailing of drainage, external levels and exposure. Coastal sites and very exposed elevations may require a more cautious approach than a sheltered garden extension.
Aluminium doors offer far more than basic white, anthracite grey or black. Many systems are available in a broad choice of RAL colours, with different internal and external finishes where required. Dual-colour frames are useful when a dark external elevation is paired with a lighter interior scheme. Check whether your chosen finish is a standard stock colour or a special order, as this can influence lead time and price.
Handles, trickle vents, cills, add-on profiles and mullion positions should also be agreed before manufacture. Small omissions can create avoidable delays on site. If ventilation requirements apply, establish whether trickle vents are needed and how they will affect the head detail and appearance of the finished frame.
Check Compliance and Site Readiness
A quality product still needs a suitable opening and correct installation. Make sure the chosen door is appropriate for the property’s location, exposure and intended use, and that the installation plan addresses fixing, packing, sealing and drainage. The frame must be installed plumb, level and square, with proper support beneath it. Expanding foam alone is not a fixing method.
For replacement work and new extensions, confirm who is responsible for Building Regulations compliance and certification. This may sit with the main contractor, installer, building control route or a competent-person scheme, depending on the project. The supplier can provide relevant product information, but supply only does not transfer the installation responsibility back to the manufacturer.
Before delivery, ensure there is safe access for unloading and moving the frames and sealed units into the property. Large sliding panels are heavy and may require mechanical handling or a planned lifting team. Check access widths, stairs, turning points, parking restrictions and the storage area. Doors should be kept dry, protected from damage and stored in line with the supplier’s handling guidance.
Review the Order Before It Goes Into Production
Once aluminium frames and glass have entered manufacture, changes can be costly or impossible. Take time to review the final quotation and drawings line by line. Confirm dimensions, opening direction, panel arrangement, colour on each side, glass type, threshold, handles, cills and delivery address. Check whether prices include VAT, delivery, unloading arrangements and any required ancillary profiles.
This final review is where a specialist supplier earns its place. Bifolding Door Factory can help customers compare named systems and turn a project brief into a clear product specification, but the person fitting a supply-only door should always be involved before production approval. That shared check reduces the chance of a beautifully made door arriving for the wrong opening.
A supply-only order works best when it is treated as part of the build, not a last-minute purchase. Give the survey, drawings and threshold detail the same attention as the steelwork and roof build-up, and the finished doors will look considered, operate smoothly and perform as intended for years to come.