Fibre Reinforced Facade Encyclopedia: Design and detailing
Public art fabrication is the engineering and manufacture of sculptural works for permanent outdoor installation, translating an artist’s form into an object that carries wind, resists impact, stands safely in a public place and survives decades of weather. It is distinct from facade work in that the geometry is not negotiable and there is no repetition to amortise tooling against, and distinct from studio sculpture in that the result is a piece of public infrastructure subject to structural certification, safety review and a maintenance regime. Fibre reinforced polymer dominates the field because it gives high strength at low weight in any shape a mould can take.
A 10 metre sculptural FRP shell can weigh less than a tonne, which is what allows a large public artwork to sit on a modest footing rather than on a piled foundation.
At a glance
| Property | Typical value | Note |
|---|---|---|
| Typical material | FRP (fibre reinforced polymer), sometimes with glass fibre reinforced concrete (GRC) elements | Strength to weight, and no limit on form |
| Skin laminate | 3 to 8 mm, locally thicker at connections | ShapeShell-RT published single skin range |
| Weight in service | 5 to 32 kg/m2 of surface | ShapeShell-RT published range |
| Wind design | AS/NZS 1170.2, with shape factors from testing or CFD | Sculptural forms are not in the code’s shape tables |
| Impact design, public zone | Assessed to the height a person can reach | Low level surfaces take deliberate and accidental impact |
| Anchorage | Base plates, embedded frames or cast-in starter bars | Overturning and torsion usually govern, not bearing |
| Finish | Gel coat, or automotive grade or PVDF topcoat | Colour, gloss and UV resistance specified as one system |
| Anti-graffiti | Sacrificial or permanent coating | Sacrificial is recoated after each clean |
| Inspection interval | Annually, with a detailed inspection every 5 years | Set in the maintenance manual handed to the asset owner |
Working with the artist
The fabricator’s first job is to acquire the form accurately and without reinterpreting it. That usually means scanning a physical maquette, or taking a digital model from the artist, then rebuilding it as a fabrication model that is watertight, correctly scaled and resolved into buildable parts. Scaling a maquette is not a neutral operation: surfaces that read well at 300 mm can flatten or distort at 10 metres, and the artist has to see and approve the scaled form before tooling is cut.
The conversations that follow are about where the work can change and where it cannot. Panel split lines, the position of a joint on a visible surface, the minimum radius a laminate can take, the depth of a return, the location of access hatches and the treatment of a base all affect how the piece reads. Settling them explicitly, with the artist signing the surface model and a sample of the finish, avoids the far worse conversation in which a fabrication decision is discovered after installation. A visual mock-up of a representative area, and a signed control sample for colour and gloss, serve exactly the same purpose here as on a facade.
Structural design of a sculptural form
A sculpture is a structure with none of the conveniences of a building. There is no grid, no obvious load path and no code table giving pressure coefficients for its shape. Wind actions are derived from AS/NZS 1170.2 for the site, but the shape factors for an irregular body have to come from wind tunnel testing, from computational fluid dynamics, or from a conservative envelope agreed with the engineer. Slender or plate-like forms also need checking for dynamic response, including vortex shedding, because a light stiff shell can have a low damping ratio.
The shell itself is analysed by finite element methods, with the laminate schedule modelled rather than an isotropic approximation, since a composite shell is only as good as the plies actually specified. Attention concentrates at three places: the connection to the foundation, where all load is collected; any internal steel armature and the interface between armature and laminate, which must accommodate different thermal movement; and the local areas around fixings, hatches and penetrations, where load is introduced into a thin laminate.
Anchorage and foundations
Most public artworks fail conceptually at the base, not in the body. Overturning moment and torsion from asymmetric wind, not bearing pressure, are usually what size the footing. Standard arrangements are a steel base plate on cast-in bolts or chemical anchors, a steel armature embedded into the footing with the laminate built around it, or starter bars cast into a concrete plinth that also serves as a plinth against vehicle and mower impact.
The details that matter are corrosion protection where steel meets concrete and where dissimilar metals meet, drainage so that water cannot pond inside a hollow form or at the base, an inspection hatch so the anchorage can actually be looked at in later years, and an allowance for differential thermal movement between a composite shell and a steel armature. Fixings and internal steelwork are specified for the design life of the work, which is normally longer than that of a building facade.
Public safety, vandalism and maintenance
- Impact: surfaces within reach are designed for deliberate and accidental impact, including people leaning, climbing and striking the work, and for mowers, trolleys and vehicles where the setting allows them close
- Climbability: if a form can be climbed it will be, so either it is designed to be climbed safely or the geometry and setting are arranged to discourage it; fall heights and landing surfaces are assessed with the client
- Edges and pinch points: no sharp arrises, no trapping gaps and no protruding fixings within reach
- Damage exposure: a punctured composite can expose glass fibre, so laminates in the public zone are built up and the repair procedure is documented before handover
- Graffiti: an anti-graffiti coating is specified as part of the finish system, sacrificial coatings being recoated after each clean and permanent coatings cleaned with approved solvents only
- Water and drainage: hollow forms are drained and ventilated so water cannot collect, freeze or breed
Handover should include a maintenance manual naming the finish system and its repair procedure, the cleaning products that are and are not permitted, the inspection interval and what each inspection covers, and the contact for structural repair. A public artwork without a maintenance manual becomes an orphan asset, and orphan assets are the ones that get removed.
Standards and references
- AS/NZS 1170.0 structural design actions, AS/NZS 1170.1 permanent and imposed actions, and AS/NZS 1170.2 wind actions
- AS 3600 concrete structures and AS 5216, design of fastenings in concrete, for base connections
- AS 4100 steel structures and AS/NZS 2312 for corrosion protection of internal armatures
- ISO 14125 and ISO 527 for laminate properties; ISO 1172 for glass content verification
- AS 1428 series, design for access and mobility, where the work sits on or beside a path of travel
- AS 4685 series, playground equipment, referenced for entrapment and impact criteria where a work is climbable
Where this matters on a ShapeShift project
Spanda, Perth: A large outdoor sculptural work in composite, where the form is the structure and the engineering sits behind a surface that has to read as a single continuous object.
Related terms
Questions specifiers ask
Why is FRP the usual material for public art?
Because it gives high strength at low weight in any shape a mould can take. A large sculptural shell can weigh under a tonne, which keeps foundations modest, makes transport and lifting practical, and allows double curvature that would be impossible to cast.
How is wind load calculated for a sculpture?
Site wind speed comes from AS/NZS 1170.2, but the shape factors for an irregular body are not in the code. They are derived from wind tunnel testing, from computational fluid dynamics, or from a conservative envelope agreed with the structural engineer.
How does the artist stay in control of the form?
By approving the scaled surface model before tooling is cut, by agreeing panel split lines and joint positions on visible surfaces, and by signing a control sample for colour, gloss and texture that every delivered element is judged against.
What is done about graffiti?
An anti-graffiti coating is specified as part of the finish system. Sacrificial coatings are removed with the graffiti and recoated; permanent coatings allow repeated cleaning with approved solvents. The permitted products belong in the maintenance manual.
What maintenance does a composite artwork need?
Periodic washing, an annual visual inspection and a more detailed inspection every few years covering the anchorage, the finish and any impact damage, plus a documented repair procedure for the gel coat or topcoat. All of it belongs in a handover manual.
Fabricating a public artwork? We engineer and manufacture sculptural composites and work from the artist’s maquette or model through to installation. Talk to our public art team
Reviewed by Richard Halvorsen, General Manager, ShapeShift Technologies. Last updated September 2026.