Steel Frames
A detailed 2026 guide for developers and builders delivering townhouse and multi dwelling projects across Melbourne and Victoria.
Light gauge steel framing has become a preferred structural system for townhouse and multi unit developments in Melbourne because it is repeatable to identical dimensions, non combustible, immune to termites and fast to erect across many units at once. Those qualities directly support the fire and acoustic separation that the National Construction Code requires between dwellings, while protecting the program on tight infill sites. This guide covers Melbourne’s medium density boom, the separation rules your build must meet, the engineering standards behind a compliant frame, and real projects we have delivered across the state.
Medium density is now the centre of gravity in Melbourne housing. Analysis drawing on KPMG forecasts reports that Victoria’s medium density approvals have risen by about 109.5 per cent over five years to roughly 23,390 approvals a year, and that attached dwelling values in Melbourne are forecast to grow 7.1 per cent in 2026, outpacing detached houses. By the end of 2025, Melbourne unit values had reached a three year high of around $656,500.
Policy is pushing hard in the same direction. Victoria has committed to 800,000 new homes over ten years, coordinated through Homes Victoria, against a federal target of 240,000 new homes a year. The state’s new Mid-Rise Code is streamlining approvals for four to six storey developments in well serviced middle ring suburbs. For developers and builders, that means a large and growing pipeline of townhouses and apartments to deliver, often on constrained infill sites and to tight feasibility margins, which puts a premium on a structural system that is fast, consistent and compliant.
A townhouse development is a repetition exercise. The same wall frames, spans and details are produced again and again across the site. Steel frames are manufactured to precise, identical dimensions, so every unit comes out the same. That consistency removes the small variations that creep into hand built framing and keeps the later trades, the cladding, lining and fit out, running smoothly across the whole development.
This is where medium density gets technical. Under the National Construction Code, townhouses that do not have one dwelling above another are generally Class 1a and are separated by a fire resisting separating wall, while stacked apartments are Class 2 with their own provisions. A separating wall has to achieve a defined fire resistance level covering structural adequacy, integrity and insulation, and it must run continuously from the footings to the underside of the roof, with eaves and roof spaces common to more than one dwelling separated by non combustible vertical lining so a fire in one home does not spread to the next.
On acoustics, the Code requires sound insulation of Rw plus Ctr of at least 50 between dwellings. Steel is non combustible, which gives a strong base for the fire requirement, and steel framed party walls are readily detailed with the insulation and resilient lining systems needed to hit both the fire and the acoustic targets. The NASH design handbook for fire resistance and sound insulation sets out tested steel framed solutions for exactly these separating wall conditions.
Infill development often means narrow access, neighbours close by and little room to store materials. Steel frames are light, arrive ready to assemble and generate far less on site waste than traditional framing, which suits constrained urban sites. The reduced weight can also simplify footings and handling on difficult blocks. Our prefabricated steel frame approach is built around this kind of fast, low waste delivery.
On a multi unit job, every day saved is multiplied across the number of dwellings. Precise, factory made frames go up quickly and predictably, which compresses the framing stage and protects the program. For developers working to tight feasibility, that means earlier completion, earlier settlement or rental income, and less exposure to holding costs and cost escalation.
Steel does not shrink, warp or twist, and it is not attacked by termites. Across a development that will be sold or tenanted, that dimensional stability means straight walls, square openings and fewer defects or callbacks after handover, which protects both reputation and warranty exposure. Engineered steel wall framing and lightweight steel roof trusses carry the loads of two and three storey townhouses efficiently.
Understanding which class your dwellings fall under, and the separation that goes with it, is the first step in getting a medium density build right. The table below summarises the key distinctions under the National Construction Code.
Item | What it means for your build |
Class 1a | Townhouses, row houses, terraces and villa units where no dwelling sits above another, separated by a fire resisting wall |
Class 2 | Apartment style buildings where dwellings are stacked vertically, with their own fire and life safety provisions |
Separating wall fire resistance | Must cover structural adequacy, integrity and insulation, and run continuously from the footings to the underside of the roof |
Acoustic separation | Sound insulation of Rw plus Ctr of at least 50 is required between dwellings |
Roof and eaves | Spaces common to more than one dwelling must be separated with non combustible vertical lining |
Source: National Construction Code 2022 Housing Provisions, Parts 9.2 and 9.3, and ABCB NCC fire separation provisions. Confirm the class and ratings for your project with your building surveyor and engineer.
Light gauge steel framing for medium density is a fully engineered, certified system. A compliant multi unit frame is designed against a defined suite of Australian Standards, which is exactly why the National Construction Code recognises it with clear compliance pathways.
Standard | What it covers |
AS/NZS 4600:2018 | Cold formed steel structures, the core design standard for light gauge steel framing |
NASH Standard | Residential and Low-Rise Steel Framing, recognised by the NCC for design, bracing and tie down |
NASH fire and acoustic handbook | Tested steel framed separating wall solutions for Class 1 and Class 2 dwellings |
AS 1170 series | Structural design actions, the loads engineers design the frame to resist |
AS 1530.4 and AS 4072.1 | Fire resistance testing and service penetration sealing for separating walls |
AS 1397 | The coated steel sheet standard governing the base material, including TRUECORE steel |
Source: NCC compliance pathways, the NASH Standard for Residential and Low-Rise Steel Framing and AS/NZS 4600:2018.
We build using Australian made TRUECORE steel, a BlueScope product manufactured to AS 1397, with section thickness specified by the engineer for the loads in each dwelling. Consistent, certified material across every unit is part of what makes steel so reliable for repeated medium density work.
Completed work is the clearest proof. CMC Steel Solutions has supplied and installed steel framing for townhouse and multi dwelling developments from inner Melbourne through to the Mornington Peninsula and the growth corridors. Full galleries are on our projects page.
Project | Scope |
Supply and install of steel framing for a townhouse development in Melbourne’s north | |
Steel framing supply and installation for a multi unit townhouse project in the west | |
Structural and light gauge steel framing for a townhouse development in the south east | |
Light gauge steel framing for a townhouse development in inner Melbourne | |
Light gauge steel framing for a townhouse development on the Mornington Peninsula |
Source: CMC Steel Solutions project records and project pages, linked above.
These developments sit within our broader residential steel frame and commercial steel framing experience, so our team can handle the structural, compliance and program demands of medium density work.
On a multi unit development, the framing decision compounds. Steel’s speed and dimensional consistency reduce on site time, waste and rework across every dwelling, and its termite immunity and stability lower warranty and maintenance exposure after handover. Set against that, steel requires correct engineering, separating wall detailing and thermal design to perform, so the right comparison is total delivered cost and risk across the development, not the framing line on a single unit. A project specific quote, accounting for the number of units, storeys and site conditions, is the most reliable guide to cost.
Yes. Steel framing carries multi level loads efficiently because of its high strength to weight ratio, and it is widely used for two and three storey townhouse and apartment construction. Each frame is engineered to the loads and layout of the specific project.
Under the National Construction Code, townhouses, row houses and villa units where no dwelling sits above another are generally Class 1a and are separated by a fire resisting wall. Apartment style buildings where dwellings are stacked vertically are Class 2 and have their own fire and life safety provisions.
Steel is non combustible, which helps with fire performance, and steel framed party walls are detailed with the insulation and resilient lining systems needed to achieve a fire resisting separating wall and sound insulation of Rw plus Ctr of at least 50 between dwellings, as required by the Code.
Generally yes. Frames are manufactured to precise dimensions off site and arrive ready to assemble, so the framing stage is faster and more predictable. On a development with many identical units, that time saving is multiplied across the site.
Yes. Steel frames are light, generate little on site waste and arrive ready to assemble, which suits narrow access, close neighbours and limited storage on urban infill blocks, and the reduced weight can simplify footings.
It is engineered to AS/NZS 4600:2018 and the NASH Standard for Residential and Low-Rise Steel Framing, with separating wall fire performance verified to AS 1530.4 and service penetrations sealed to AS 4072.1. The base material is coated steel made to AS 1397, such as TRUECORE steel.
We supply and install steel framing for townhouse and multi unit developments across metropolitan Melbourne and regional Victoria, including completed projects in Doreen, Hoppers Crossing, Narre Warren, Toorak and Sorrento.
If you are delivering a townhouse or multi dwelling development across Melbourne or Victoria, our team can frame it consistently, compliantly and on program. We supply and install structural and light gauge steel framing built with Australian TRUECORE steel, engineered to AS/NZS 4600 and the NASH Standard and backed by a portfolio of completed medium density projects.
Call us on 1300 285 566, email info@cmcsteelsolutions.com.au, or request a free quote to discuss your project.
Are you looking for steel framing solutions? We at CMC Steel Solutions offer wide range of products for construction projects.
Connect with our team at 1300 285 566 or email us your doubts on info@cmcsteelsolutions.com.au for better response.
