Structural steel frames, façade steelwork and internal structures — engineered, fabricated and installed for offices, retail spaces, education and public facilities across Melbourne, from our Keysborough workshop.
A.C. Steel provides structural steel solutions for offices, retail spaces, education facilities and public buildings across Melbourne and regional Victoria — multi-storey frames, architectural and façade steelwork, commercial roofing, internal steel systems and carpark structures. Below: how we approach each commercial building type, what drives the cost of a commercial steel package, the standards to check a fabricator against, and our typical delivery timeline from drawings to handover.
Different commercial building types carry different spans, loads and compliance requirements. Here's how each is typically approached.
Full steel skeletons — columns, floor beams and lateral bracing — for buildings needing large open spaces, high ceilings and minimal internal columns.
Usually CC2Structural steel for shopfronts, mezzanine retail floors and internal bracing that opens up floor plates, plus fit-out steel for partitions and tenant works.
Usually CC2Trusses and purlins for long-span roofs, plus canopies, awnings, exposed beams and decorative façade framing — engineered structure with a design-led finish.
Usually CC2Fire-rated stairs, balconies with balustrade connections, and structural framing for lift shafts, atriums and mezzanines.
Fastest turnaround packageHeavy-duty columns, beams and transfer slabs for basement carparks and podium levels, with corrosion-protected finishes for damp environments.
Usually CC2Steel structures for classrooms, halls and institutional additions, where fire rating, acoustic separation and staged construction around an operating site add complexity.
CC2–CC3 dependent on useWe supply and install multi-level structural steel frames, ideal for commercial buildings requiring large open spaces, high ceilings and minimal internal columns.
For projects with a strong visual focus, we work closely with architects to deliver architectural steel elements that are both functional and eye-catching.
We fabricate and install complete structural steel roof framing, suited to various commercial building types.
A wide range of internal structural steel components for vertical circulation and structural support.
Heavy-duty steel structures for basement carparks, podium levels and commercial parking areas, built to handle vehicle loadings and fire safety requirements.
| Grade | Standard | Typical Use |
|---|---|---|
| Grade 300 / 300PLUS | AS/NZS 3679.1 | The most common structural steel grade in Australia (min. 300MPa yield). 300PLUS is the quality-assured Grade 300 product most Australian structural sections are supplied as. |
| Grade 350 | AS/NZS 3679.1 | Higher yield strength, used where a longer span or heavier load makes a lighter Grade 350 section more efficient than a heavier Grade 300 one. |
AS 4100 is the structural design standard for steel buildings in Australia — the NCC references it as the standard for structural steel design. It governs how your structural engineer sizes members and connections against axial, bending and shear loads, and checks for buckling and stability. AS 4100 is a design standard, not a fabrication or installation standard — so "AS 4100 compliant" describes the engineering behind a structure, not the workshop that built it. What governs fabrication and installation quality is AS/NZS 5131. Read our full AS 4100 guide →
AS/NZS 5131 sets the execution — fabrication and installation — requirements for steel structures, and assigns every project a Construction Category based on a risk assessment your structural engineer carries out. As a general guide (industry interpretation — your engineer's classification governs):
| Category | Typical Scope |
|---|---|
| CC1 | Light commercial work — basic documentation. |
| CC2 | Where most standard commercial projects sit — offices, retail buildings, multi-storey fit-outs — with enhanced QA. |
| CC3 | Critical commercial or public buildings — full material traceability and NDT testing. |
| CC4 | Highest category — critical infrastructure, comprehensive QA system. |
The higher the category, the more the standard requires in welding procedure qualification, inspection/testing coverage, and documentation at handover. When briefing a fabricator, the useful question isn't "are you AS 5131 certified" — the standard doesn't work as a company-wide certificate. Ask instead: "Can you show me how your welding procedures, inspection records and documentation meet CC2 for this project?" — ask for evidence, not a badge. See our full CC1–CC3 breakdown →
AS/NZS 1554.1 is the structural steel welding standard, covering steels up to 500MPa yield strength — it sets welding procedures, welder qualification and quality categories. Any commercial fabricator should be able to show welder qualifications and Welding Procedure Specifications (WPS) aligned to this standard for your project's Construction Category.
NATA accredits testing laboratories and inspection bodies — not individual companies. If your project requires non-destructive testing (more common at CC2 and above), check that the testing itself is carried out by a NATA-accredited lab, not just requested by the fabricator.
For most Victorian commercial builds, your structural engineer issues a Certificate of Compliance – Design (Regulation 126) under the Building Act 1993 and Building Regulations 2018, confirming the structural design — including the steel — meets the NCC and relevant Australian Standards, for your Building Surveyor's permit file. As your fabricator, we work directly from your engineer's drawings and coordinate with your surveyor's documentation needs — the Regulation 126 certificate itself is issued by your structural engineer.
Every commercial steel quote is built from the drawings. We don't publish fixed prices — no two commercial projects price the same way — but here's context to sanity-check a quote against.
| Item | Reference Range |
|---|---|
| Structural steel — fabrication only (material + workshop) | approx. $2,300–$2,800 / tonne |
| Structural steel — fabrication, supply & installation | approx. $3,000–$4,000 / tonne installed |
| Portal frame warehouse — steel frame only | approx. $120–$200 / m² |
| Portal frame warehouse — turnkey (frame, slab, cladding, basic fit-out) | approx. $1,500–$2,800 / m² |
| Mezzanine floor — steelwork supply only | approx. $250–$350 / m² |
| Mezzanine floor — supply & install, storage-grade | approx. $300–$500 / m² |
| Mezzanine floor — office-fit or complex/custom | approx. $400–$800+ / m² |
We review your drawings (or help you get to drawings if you don't have them yet), confirm scope, and where useful, visit site to check access, existing structure and staging constraints. Typically 1–3 days to turn around an initial scoped estimate once we have drawings.
Our in-house drafting team produces shop drawings and connection details from your engineer's structural design using AutoCAD/3D modelling. Typically 1–3 weeks for a standard commercial package; highly custom or multi-stage projects take longer. More on our shop drawing process →
We order certified 300PLUS/Grade 350 steel to specification, with mill certificates for traceability. Lead time depends on section availability and current market supply.
Cutting, welding (to AS/NZS 1554.1) and assembly in our Keysborough workshop. Standard-span commercial packages typically take 3–4 weeks in the shop; larger or highly custom jobs can take up to 6 weeks.
Steel is delivered and installed on your program, coordinated with your builder or site manager, including crane bookings and temporary works where needed.
Final checks against approved drawings, with mill certificates, welding records and as-built documentation handed over — the paperwork your Building Surveyor and structural engineer will want on file.
Typical overall timeframe: for a straightforward single-storey commercial steel package, allow 3–6 months from approved drawings to installed steel. The biggest scheduling factor is usually shop drawing approval and material lead time — not cutting and welding.
Full written project case studies (scope, span, tonnage, timeline) are in development — see our Projects page.
We handle design coordination, CAD/shop drawings, fabrication and on-site installation, working directly with your structural engineer and builder.
Yes. AS/NZS 5131 Construction Categories set the level of quality assurance a project requires: CC1 covers light commercial work with basic documentation; CC2 is where most standard commercial and multi-storey projects sit, with enhanced QA; CC3 covers critical commercial or public buildings, with full material traceability and NDT testing; CC4 is the highest category, for critical infrastructure, with a comprehensive QA system. We provide documentation appropriate to whichever CC level your structural engineer specifies — for CC3/CC4 that typically includes welding procedure specifications (WPS), welder qualifications and NDT reports. Your engineer makes the classification; we deliver the paperwork that matches it.
AS 4100 is a design standard applied by your structural engineer, not a certification a fabrication company holds. Our fabrication and welding processes are built to meet the AS/NZS 5131 and AS/NZS 1554.1 requirements that flow from your engineer's AS 4100 design.
Yes — we regularly tender for commercial steel packages of varying scope. A tender response typically includes a detailed scope of work, bill of materials with mill specifications, tonnage and labour breakdown, a program aligned with your construction timeline, compliance documentation (AS 4100, AS/NZS 5131, AS/NZS 1554.1), insurance certificates, and references from comparable projects. Send your tender package (drawings, spec and tender form) to info@acsteelconstruction.com.au — pre-tender site visits are available on request.
Maximum height, span and component weight depend on your specific design — your structural engineer specifies the configuration, and we fabricate to AS 4100 and AS/NZS 5131. For larger spans or taller structures, steel can be modularised and assembled on site, with mobile crane coordination for components exceeding our standard lifting capacity. Send us your concept drawings and we'll confirm what's achievable in our workshop and what would need additional logistics.
Commercial steel requires fire-resistance levels (FRLs) specified per NCC Section C. Common approaches include intumescent paint (expands when heated to form an insulating char, suited to visible steel), cementitious spray coating (cost-effective for concealed steel), box-encasement in plasterboard (common for exposed office fit-out beams), and galvanised steel combined with fire-rated cladding. The FRL required depends on building class, height and occupant load. A.C. Steel supplies the steel — fire-protective coating is typically a separate trade, which we can coordinate with or recommend specialists for.
Yes — we regularly accommodate projects with operating tenants: staged delivery so components arrive in installation sequence rather than sitting in storage, after-hours or weekend installation to minimise business disruption, coordination with your building manager on access and noise restrictions, loading-dock-only delivery where street loading is restricted, and temporary floor protection or dust barriers where needed. After-hours premiums apply — discuss your site constraints with us when getting a quote.
Yes — fit-out steel is a regular part of our work, including structural steel supports and headers for partition and bulkhead framing, steel mezzanines for storage or break-out areas, structural steel backing for acoustic wall systems, support steel for demountable partition layouts, and feature staircases for multi-level office fit-outs. We work with shopfitting companies and tenant rep firms across Melbourne — for tight fit-out deadlines, contact us early to discuss lead times.
Yes — send us the structural drawings and we'll produce shop drawings and a scoped quote from them.
Yes — mill certificates for steel traceability and welding records aligned with AS/NZS 1554.1 are provided as part of project handover.
It depends on tonnage, span and height, finish (raw, painted or galvanised), connection complexity, fire protection requirements, site access and Construction Category — see the cost driver section above for reference ranges. We can provide tonnage estimates from concept drawings, and tender-ready pricing once we have full structural drawings.
For a straightforward single-storey package, typically 3–6 months from approved drawings to installed steel. Shop drawing approval and material lead time are usually the biggest factors, not fabrication itself.
Yes — supply and install of mezzanine steelwork including bearers, joists, columns, stairs and balustrades, for storage, office or light industrial fit-outs.
We're based in Keysborough and service Melbourne metro and surrounding regions, with particular strength across the south-east corridor.
Yes — multi-trade coordination is standard for commercial projects. Typical workflow: a single point of contact for your project, progress updates during fabrication, shop drawings circulated for engineer/PM sign-off before fabrication starts, installation sequenced with your concreter, electrician and other trades, and site meetings attended on request, with snag-list resolution included at handover.
Practical answers for commercial developers, builders, and project managers planning structural steel packages in Melbourne.
At A.C. Steel, we specialise in structural steel solutions tailored for residential, commercial, and industrial builds. We help builders and architects deliver structurally durable, cost-effective, and on-time projects.