A folding door can make a wide opening more usable by gathering its panels at one or both sides. That benefit depends on decisions made before fabrication: the opening must be measured in the right condition, the panels need somewhere to stack, and the selected frame, glass, hardware, and sill detail must work as one system. This guide helps architects, builders, and owners prepare a clearer request for a custom folding door package.
Begin With the Operating Plan
“Folding door” describes the movement, not a single layout. A two-panel unit may fold to one side; a larger opening can divide its panels between both sides. The preferred arrangement is determined by circulation, furniture, views, the available wall beside the opening, and which panel should provide everyday access.
Mark the intended stack location on an elevation before comparing quotes. A folded set still occupies part of the opening or adjacent wall zone. It can affect curtains, exterior screens, railings, switches, furniture, and the route people use to reach a terrace or garden. Ask the supplier to show the parked-panel position and the clear passage on the shop drawing rather than relying on a render.
Do not treat the visible opening width as the final order size. The order dimensions, finished opening, rough opening, and clear opening can all be different. The project team should define which one appears on the drawing and obtain the manufacturer’s required tolerances for the selected system.
Survey the Opening Before Selecting Panels
For a replacement project, measure the prepared opening at the top, middle, and bottom, then measure the height at both sides and the center. Record both diagonals, the sill level, and the jamb plumb. These readings reveal taper, twist, or settlement that a single width-and-height measurement can hide.
For new construction, coordinate the door with the structural opening and the completed wall build-up. Head support, jamb backing, cladding depth, waterproofing, interior finishes, and threshold height all influence the interface. A folding door should be configured around that interface, not inserted after the wall detail is complete.
| Item to record | What to show | Why it changes the order |
|---|---|---|
| Opening condition | Rough opening or finished reveal, plus wall layers. | Keeps frame sizing and perimeter clearances aligned with the actual construction stage. |
| Configuration | Panel count, fold direction, daily access panel, and viewing side. | Determines handing, hardware position, stack location, and usable passage. |
| Exposure | Floor level, orientation, wind exposure, and weather protection. | Guides the engineering review of frame, glass, seals, drainage, and anchors. |
| Sill and drainage | Interior and exterior finish heights, slope, flashing, and water path. | Prevents a low-threshold choice from conflicting with water management at the wall. |
Specify the System as a Whole
Frame and glass
Ask for the proposed profile, thermal-break approach, glass build-up, finish, and color arrangement in writing. Thermal and solar decisions should reflect the project location, orientation, shading, and energy requirements. Safety glazing, laminated glass, acoustic needs, and privacy treatments also need to be identified by location instead of added generically at the end of a quotation.
Hardware and panel loads
The track, rollers, pivots, hinges, locks, handles, and guides carry out the design intent. Their suitability depends on the actual panel dimensions, glass weight, opening direction, and expected use. Request a drawing that identifies the active panel, locking points, handle location, and any hold-open or child-safety requirement. Hardware selection should be checked with the door system, not chosen as a separate decorative item.
Weather and wall connection
A door frame cannot compensate for a missing water-management detail. Coordinate the sill pan or flashing, exterior drainage path, perimeter seals, and anchor zones with the wall assembly. Where a project also uses a 24 inch entry door or other exterior door type, keep each opening’s performance requirements distinct while coordinating finish, glass appearance, and threshold transitions across the elevation.
Use a Drawing Review That Catches Costly Changes Early
Before releasing a custom unit, compare the shop drawing against the architectural opening schedule and site measurements. Review the frame outside dimensions, panel arrangement, active leaf, swing or fold direction, visible sightlines, glass description, threshold, drainage, hardware, and wall fixing method. Confirm the stated view direction for every handing note; left and right can reverse when a drawing is viewed from the opposite side.
For broad façade packages, include the folding unit in a single coordinated review with nearby windows and doors. A supplier experienced with integrated aluminum systems can help align repeated details, but the project professional remains responsible for the site-specific structural, weather, and code decisions. When comparing swing door manufacturers and folding-system suppliers, ask each bidder to respond to the same drawing and performance brief so differences are visible.
A Practical Request-for-Quote Checklist
- Project location, building type, floor level, and opening reference.
- Measured opening dimensions, diagonals, sill level, jamb condition, and whether the figures are rough or finished.
- Elevation showing panel count, fold direction, active panel, stack zone, and viewing side.
- Required clear passage, accessibility needs, and any local life-safety requirements to be verified by the project team.
- Frame finish, interior and exterior color arrangement, glass build-up, safety treatment, and screen requirements.
- Project performance criteria for thermal behavior, air and water control, structural loading, acoustic control, or impact resistance where applicable.
- Threshold detail, flashing concept, drainage path, perimeter sealing responsibility, and anchor interface.
- Required submittals: sections, hardware schedule, samples, shop drawings, packaging plan, delivery sequence, and spare parts.
Include photos of the opening and adjacent conditions with the request. They often reveal obstructions and finish transitions that a plan dimension does not show. A complete brief gives the supplier a sound basis for a custom proposal and gives the buyer a practical way to compare it.
Prepare the Brief Before You Request a Custom Quote
ALPES manufactures custom aluminum window and door systems for international residential and commercial projects. Share the opening information, intended configuration, finish, glass, and wall details through the ALPES contact page to begin a specification review.
