concertina door installed in a doorway in a school in Melbourne that previously had no door installed - before and after collage

Can You Install a Folding Door in an Existing Doorway?

Yes, in many cases, you can install a folding door in an existing doorway without rebuilding the entire opening. The key is determining whether the opening has suitable dimensions, adequate structural support and enough clearance for the door to operate and stack neatly when open.

For many commercial renovations, office fit-outs, classrooms, meeting rooms and internal residential applications, installing a folding door can be a practical way to change how a space is used without undertaking a major renovation.

However, not every existing doorway is automatically suitable. The frame, floor, overhead fixing points and available parking space for the folded panels all need to be considered before selecting a door system.

At Australian Folding Doors, we manufacture folding doors in Melbourne to suit project requirements and supply them to customers across Australia, even to Darwin, NT.

Whether you are dividing a commercial room, replacing an old concertina door or making better use of an existing space, understanding a few important details can help you plan the project with confidence.

1. Can a Folding Door Fit an Existing Doorway?

In many situations, yes. An existing doorway can often accommodate a folding door if its dimensions, configuration and supporting structure are suitable for the proposed system.

For example, a business might want to divide an office meeting room, separate a treatment room, close off a staff area or create more flexible space in a community facility. Rather than constructing a new permanent wall, a folding door may allow the opening to be closed when privacy or separation is needed and opened when a larger space is required.

The same principle applies when replacing an older folding or concertina door. The existing opening may be reusable, although the dimensions, frame condition, fixing points and requirements of the replacement system should be checked rather than assumed.

The important starting point is not whether the opening was originally designed for a folding door. It is whether the existing conditions can accommodate the new system safely and practically.

A custom-manufactured door may provide more flexibility than trying to find a standard product that happens to match the opening. Nevertheless, custom manufacturing cannot compensate for inadequate structural support or insufficient clearance.

2. What Should You Check Before Installing a Folding Door?

Before choosing a folding door for an existing doorway, there are several practical considerations worth assessing.

Opening width and height

Accurate measurements are essential. The width and height of the opening help determine the door configuration, panel arrangement and overall suitability of the proposed system.

Do not assume the opening is perfectly square or that the width and height are identical at every measurement point. Older buildings, renovated spaces and commercial premises can have variations that affect the final fit.

It is helpful to record the width at the top, middle and bottom, along with the height at both sides and in the centre. Any significant differences should be communicated to the door supplier before manufacturing begins.

These measurements are a starting point for assessing the opening, not a substitute for confirming the final manufacturing dimensions and installation requirements

The existing frame and jambs

The jambs are the vertical sides of the opening. Depending on the folding door configuration, they may be needed for starter brackets, fixing points, latching components or the parking position of the folded panels.

An existing timber or steel frame may be suitable, but its condition and fixing arrangements need to be considered. A frame that is loose, damaged or unsuitable for the proposed fixings may require attention before installation.

It is also important to establish whether the opening has a frame at all. Some commercial openings are formed using structural elements, while others may have plasterboard finishes around the opening.

The appearance of a finished wall does not necessarily reveal what is behind it. Where the fixing arrangement is unclear, the builder or another appropriately qualified professional should assess the existing construction.

Floor level and variation

Floor conditions can influence how a folding door operates and how effectively it meets the floor when closed.

Existing buildings may have sloping floors, uneven surfaces, thresholds or changes in floor height. These details should be identified early rather than discovered after the door has been manufactured.

Some folding door systems use flexible sweep seals that can accommodate a degree of floor variation. Australian Folding Doors offers systems designed to accommodate certain uneven-floor conditions, depending on the product and installation requirements.

However, the amount of variation that can be accommodated depends on the system selected and the actual site conditions. A floor assessment is therefore an important part of planning the installation.

Head clearance and overhead support

The top of the opening is particularly important because the folding door operates on a track.

The track must be fixed to suitable supporting structure capable of carrying the door system's weight. A finished ceiling or plasterboard lining should not automatically be treated as adequate structural support.

In an existing doorway, the necessary support may already be present. In other cases, the builder may need to assess the opening and determine whether changes are required.

The correct solution depends on the building and the proposed door arrangement. Australian Folding Doors can advise on the weight and requirements of its door system, but structural adequacy and any required modifications must be determined by the builder, engineer or other appropriately qualified professional.

For further information, see our guide to structural support for folding door tracks.

3. Do You Need to Remove the Existing Door Frame?

Not necessarily. Whether the existing frame can remain depends on its condition, dimensions, construction and compatibility with the proposed folding door.

If the frame is sound, suitably positioned and capable of providing the required fixing points, it may be possible to use the existing arrangement. This can help reduce unnecessary demolition and disruption.

However, retaining a frame simply because it is already there is not always the best approach. An unsuitable frame, inadequate fixing points or an opening that does not provide the required clearances may mean changes are needed.

For example, a doorway originally built for a conventional hinged door may have a different arrangement from one intended for a full-width folding partition. The existing frame may also interfere with the folding panels, starter brackets or the amount of opening available when the door is stacked back.

The correct approach is to assess the actual opening and proposed door configuration before deciding whether any part of the existing frame should be retained, altered or replaced.

This is particularly important in commercial renovations, where minimising disruption is desirable but the finished installation still needs to function correctly.

4. How Much Space Does a Folding Door Need When Open?

One detail that is easy to overlook is the space occupied by the door panels when they are folded back.

A folding door does not disappear into the wall. The panels gather together at one or both sides of the opening, creating what is commonly called the door stack.

The amount of space required depends on the opening width, panel configuration and the particular door system. It also affects how much clear passage remains when the door is open.

For Australian Folding Doors' configurations, the typical stack allowances we use as a planning guide are:

Single-door configuration: approximately 13–14% of the opening width, plus 70 mm, for the stack at the jamb.
Bi-parting configuration: approximately 7–8% of the opening width, plus 70 mm at each jamb, with the panels stacking at both ends.

These are useful preliminary allowances for our systems, not universal measurements for every folding door on the market. The final arrangement should be confirmed for the specific project.

Consider where people will walk, where furniture or equipment will sit, and whether the folded panels could obstruct nearby doors, cupboards or access routes. In commercial settings, these practical details can make a substantial difference to the usefulness of the finished space.

If you are planning an opening with limited clearance, read our guide to concertina door stack width and opening sizes.

5. Can You Install a Folding Door Without Major Renovations?

Often, the attraction of installing a folding door in an existing doorway is the opportunity to improve a space without undertaking a major building project.

A suitable existing opening may allow the new door to be installed with relatively limited changes. This can be particularly valuable in offices, schools, community facilities and commercial premises where downtime and disruption need to be managed carefully.

For example, a business might want to divide one large meeting room into two smaller spaces, create a private consultation area or separate a staff room from a shared facility. If the opening and supporting structure are already suitable, a folding door may provide a flexible alternative to building a permanent wall.

Nevertheless, it is important not to assume that every installation will be straightforward. Some openings may require frame alterations, additional structural support, changes to finishes or other work by the building contractor.

The best way to avoid unnecessary surprises is to assess the opening before the door is ordered.

Confirming measurements, fixing conditions, floor levels and panel parking space early can help the supplier and project team identify potential issues before they affect the installation schedule.

Read about our work with Home of The Arts, in Surfers Paradise, and how we worked closely to create up to 4 changing rooms out of a large floor space, using our custom made concertina folding doors.

6. Can You Replace an Old Concertina Door Using the Existing Opening?

Yes, an existing opening can often be considered for a replacement folding or concertina door.

In some projects, the opening and supporting structure remain suitable even though the original door is worn, difficult to operate or no longer meets the needs of the space.

This can be particularly relevant in schools, sports clubs, community halls, offices and other commercial buildings with older folding door systems.

However, a replacement should not be treated as a simple like-for-like swap until the existing conditions have been assessed. The replacement system may have different panel dimensions, track requirements, fixing positions, stack allowances or performance characteristics.

It is worth checking:

The current opening width and height.
The condition and suitability of the existing frame and supporting structure.
The location and condition of the current track and fixings.
Whether the existing parking arrangement still suits the way the room is used.
Whether improved visual separation, thermal performance or acoustic separation is required.
Whether the proposed replacement can be installed without interfering with other building elements.

A replacement project is also an opportunity to reconsider whether the original door configuration remains the best option.

For a more detailed explanation, read our article on our work replacing heavy timber acoustic accordion doors in schools, and how the Subiaco Football Club in Perth replaced their old concertina doors with our robust folding door system.

7. What If the Existing Doorway Is Not Perfectly Square?

Not every existing opening is perfectly plumb, level or square. This is common enough in renovations and older buildings that it should be considered during the planning stage.

The important question is how much variation exists and whether the proposed folding door system can accommodate it.

For example, a floor that slopes slightly across an opening may affect the clearance beneath the door panels. A head that is not level can also complicate the installation because the track needs to be positioned correctly.

Some systems incorporate flexible seals that help manage certain floor variations. However, seals do not eliminate every problem associated with an uneven opening, and significant variations may require the builder to address the underlying conditions.

Accurate measurements and clear communication between the door supplier, installer and building contractor help determine the most appropriate solution.

If the opening is irregular, provide the supplier with the measured dimensions and details of the site conditions as early as possible. This allows the proposed configuration to be assessed before manufacturing begins.

8. Which Folding Door Is Best for an Existing Opening?

The right folding door depends on what the room needs to achieve. An existing doorway used for occasional visual separation may have very different requirements from a school room that needs improved acoustic separation or a space where retaining heating and cooling is important.

At Australian Folding Doors, our systems are designed for different applications.

LINEAflo — practical visual separation

LINEAflo is worth considering when the main objective is to separate spaces visually or provide everyday privacy. Potential applications include treatment rooms, fitting rooms, serveries, staff areas and other internal spaces.

COMFORTflo — helping manage drafts and thermal separation

COMFORTflo incorporates top and bottom sweep seals designed to help close gaps around the door. It can be worth considering where reducing drafts and helping retain conditioned air within a room are important priorities.

ACOUSTICflo — sound separation between rooms

ACOUSTICflo is designed for applications where sound separation matters, including education facilities, meeting rooms and other commercial environments. The appropriate system should be selected according to the project's acoustic requirements and any applicable performance evidence.

The key is to start with the purpose of the door, rather than choosing a product based on appearance alone. The opening dimensions, supporting structure, available space and required performance should all be considered together.

9. What Information Should You Provide When Requesting a Quote?

Providing useful information at the beginning can make it easier to determine whether a folding door will suit an existing doorway.

You do not need to know all the technical answers before contacting a supplier. However, a few details can help establish the requirements of the project.

Useful information includes:

The approximate opening width and height.
Whether the opening is existing or part of a new renovation.
Whether there is a timber frame, steel frame or another construction arrangement.
Any known details about the overhead support and track fixing points.
The floor type and whether there are noticeable changes in floor level.
Whether the door should fold to one side or split into two stacks.
The main reason for installing the door: privacy, visual separation, thermal separation or sound reduction.
Your location and whether installation assistance is required.

Photographs of the opening can also be useful, particularly if they show the full doorway, both jambs, the head above the opening and the surrounding space where the folded panels will sit.

For more detailed preparation, our folding door measuring guide explains the measurements to consider.

The final manufacturing dimensions and installation requirements should still be confirmed before the door is made.

10. Why Consider a Custom-Made Folding Door?

Existing openings are not always standard sizes, particularly in older buildings and commercial spaces that have been modified over time.

A custom-manufactured folding door can offer flexibility in selecting the configuration and system to suit the project, subject to the opening, support and operating requirements.

Australian Folding Doors manufactures folding door systems in Melbourne and supplies projects nationally - read about how our concertina accordion doors helped customers in various states - Brisbane, Hobart, Sydney and more. We work with customers who need internal folding doors for commercial and selected larger residential applications, including new projects and replacement installations.

For customers outside Melbourne, national supply means you can enquire about a project without needing a local Australian Folding Doors office in your state.

Installation arrangements depend on the project location and scope.

The aim is to help customers identify a suitable door system for the opening and intended use, rather than assuming one standard arrangement will suit every building.