Fibre Reinforced Facade Encyclopedia: Manufacturing
A mock-up is a full size assembly of part of the facade, built either in a testing laboratory or on site, used to settle appearance and to prove performance before the rest of the facade is manufactured. There are two distinct kinds and they answer different questions. A visual mock-up settles what the facade will look like. A performance mock-up, tested to AS 4284, settles whether the assembled system keeps water and wind out and survives the structural loads it will see in service.
A performance mock-up is typically two bays wide and two storeys high and includes at least one vertical joint, one horizontal joint, one corner and one window or penetration, because those are the places facades actually leak.
At a glance
| Property | Typical value | Note |
|---|---|---|
| Visual mock-up purpose | Appearance approval | Colour, finish, texture, joint width, panel flatness |
| Performance mock-up purpose | System performance to AS 4284 | Air, water, structural and movement behaviour |
| Typical performance mock-up size | 2 bays wide by 2 storeys high | Must include joints, a corner and a penetration |
| Test pressures | Derived from the AS/NZS 1170.2 design wind pressure | Serviceability and ultimate cases both applied |
| Water test pressure | Commonly 30 percent of serviceability design pressure | Project specific; nominate the figure in the specification |
| Lead time | 8 to 16 weeks from award | Fabricate, erect, book the laboratory, test, report |
| Position in programme | Hold point before bulk manufacture | Stated in the specification, not assumed |
| Control sample | Signed and retained physical sample | The benchmark every delivered panel is judged against |
| Retention period | Until practical completion | Stored out of weather and daylight |
Visual mock-up
A visual mock-up is about appearance and nothing else. It is normally built on site, in daylight, at the orientation the facade will actually face, because colour and texture read differently in direct sun, in shade and in raking light. It is where a design team settles the finish, the colour and its acceptable variation, the joint width and the joint shadow, panel flatness and the treatment of corners, reveals and returns.
The important output is not the mock-up itself but the decision it produces. Once the appearance is agreed, a signed control sample is taken, usually a panel section or a set of sample plates, signed and dated by the architect and the contractor, and retained. Every delivered panel is then judged against that sample rather than against an opinion. Without a control sample, a dispute about colour consistency has no reference point and cannot be resolved.
Performance mock-up and the AS 4284 sequence
AS 4284 sets out the testing of building facades and is the Australian reference for performance mock-ups. The tests are run in a defined order, because each one is intended to be performed on a specimen that has already survived the previous one. A representative sequence is:
- Preliminary air infiltration, establishing a baseline leakage rate
- Static pressure water penetration at the nominated test pressure
- Cyclic or dynamic water penetration, which reproduces the gusting that drives water into joints
- Structural test at serviceability pressure, measuring deflection of members and panels
- Repeat air and water tests, to confirm nothing has been opened up by the structural loading
- Inter-storey movement or racking, where the building will impose frame movement on the facade
- Structural test at ultimate pressure, a safety check in which permanent set is permitted but failure is not
What this proves is the system, not the panel. Panels rarely leak through the middle. Water gets in at joints, at the interface with windows, at corners, at flashings, at the head and sill, and around penetrations, all of which are assemblies of several trades’ work. That is why a mock-up that omits a corner or a window junction has tested the easy part.
Using a mock-up as a hold point
A mock-up only protects the project if the specification says production cannot start until it is approved. Written as a hold point, it gives the design team an opportunity to correct a detail while the correction is cheap. Written as a deliverable with no consequence, it is often built after production has begun, at which point the only realistic options are to accept what has been made or to argue about it.
The clause needs to name four things: which mock-up is required and of what extent, what it must demonstrate and against which test standard, who witnesses and who approves, and what happens on a failure. A failed performance mock-up normally means rectify, retest and bear the cost of both, so the allocation of that cost should be explicit rather than implied.
What a mock-up cannot do
A mock-up is a snapshot of one carefully built assembly. It proves the design works when built correctly; it does not prove the rest of the facade will be built the same way. Site workmanship, sealant application, packing and setting out still have to be controlled through inspection and through the installation regime, and site water testing of completed areas is a useful complement rather than a duplication.
Nor does it substitute for the product evidence behind the panel. Fire classification, structural properties, durability and finish performance come from product testing and from production records. The mock-up tests how those components behave once assembled into a wall.
Standards and references
- AS 4284, testing of building facades
- AS/NZS 1170.2 wind actions, for deriving serviceability and ultimate test pressures
- AAMA 501 and ASTM E283, E331 and E1105, the equivalent North American facade test methods
- EN 12152, EN 12154 and EN 13116, air permeability, watertightness and wind resistance of curtain walling
- CWCT Standard for systemised building envelopes, used in the United Kingdom
- AS 5113 and AS 5637.1, where fire performance evidence is required for the external wall (check the edition of the NCC adopted in your jurisdiction)
Related terms
Questions specifiers ask
What is the difference between a visual and a performance mock-up?
A visual mock-up settles appearance, usually on site in daylight, and produces a signed control sample. A performance mock-up is tested to AS 4284 for air leakage, water penetration, structural behaviour and movement, and proves the assembled system.
What does AS 4284 testing actually prove?
That the assembled facade, including its joints, corners, flashings and window interfaces, resists air leakage and water penetration at the nominated pressures and carries serviceability and ultimate wind loads without failure. It does not test fire performance.
How big does a performance mock-up need to be?
Large enough to include representative joints, at least one corner and at least one window or penetration. Two bays by two storeys is a common arrangement, but the extent should be specified for the particular facade.
When should a mock-up be built?
Before bulk manufacture, written into the specification as a hold point. Building it after production has started removes the only useful thing it does, which is to let a detail be corrected cheaply.
What is a control sample for?
It is the physical benchmark for finish and colour. Signed and dated by the architect and contractor and kept until practical completion, it gives any argument about colour consistency an agreed reference instead of an opinion.
Planning a mock-up programme? We build visual and performance mock-ups for glass fibre reinforced concrete, glass fibre reinforced gypsum and FRP facades and can advise on extent and sequencing. Talk to our project team
Reviewed by Richard Halvorsen, General Manager, ShapeShift Technologies. Last updated September 2026.