The short answer
Check four things before you commit: whether you need council approval, whether the roof frame and pitch suit metal, what goes under the sheets to manage condensation and noise, and which steel suits your distance from the sea. A roofer should look at the frame before you commit.
This is general information, not legal or insurance advice. Check your own strata plan, by-laws and policy, and ask a qualified adviser about your situation.
Check approvals first
Some work around the home is exempt development, which means it can go ahead without planning approval. The NSW Government says exempt work has to meet the building standards in the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008. Its guide to exempt development says the work must comply 100% with every relevant standard, or you need approval. Exempt work must also comply with the Building Code of Australia.
Heritage changes the picture:
- Exempt development can’t be carried out on land listed on the State Heritage Register or under an interim heritage order (NSW Government).
- The NSW Government says the standards may also limit work in heritage conservation areas.
- Councils set their own rules. The City of Sydney, for example, requires an exemption request when works affect a local heritage item or a building in a heritage conservation area. It describes the minor works it can exempt as typically like-for-like replacement or repair.
- Inner West Council’s heritage controls ask owners to keep original roof cladding, and to base replacement materials on the originals where repair isn’t possible.
Changing from tiles to metal isn’t like-for-like. So if your home is a heritage item or in a heritage conservation area, ask your council before you sign anything. The NSW Government’s advice is to check with your local council early.
Will your roof frame and pitch suit metal?
Monier, a roof tile maker, says a home’s roof pitch and structure were designed for a specific material. It says lightweight roofing may not have been factored into the home’s structural performance and could need engineering advice.
Two things a roofer will check:
- Pitch. Each metal profile has a minimum pitch. Lysaght’s installation manual lists 5 degrees for its Custom Orb corrugated sheet. It lists 2 degrees for Klip-Lok 700 Hi-Strength, and 1 degree for the thicker sheet on enquiry.
- Battens and fixings. The same manual says the strongest wind forces on a roof pull it outwards, and the fasteners have to resist them. It says the battens and roof framing must be properly fixed to the rafters and walls. Metal sheets also have maximum support spacings, set out in the maker’s tables.
Tiles are heavier and need stronger framing, Lysaght says.
What goes under the sheets
Condensation. YourHome says significant condensation can form on the underside of metal roofing. It recommends a correctly specified and installed membrane that drains condensation clear of the building without leaking. It says best-practice roofing uses vapour-permeable membranes. See our guide to roof leaks and condensation.
Insulation. YourHome’s insulation guide says to use sarking or foil-backed insulation under metal roofs, and recommends a vapour barrier there to reduce the chance of condensation and corrosion. Reflective foil needs an air space of at least 25mm to work.
Rain noise. Lysaght says rain on a steel roof can sound louder than on tiles, and that insulation, sarking and ceiling treatments manage this. Its manual says an insulation blanket held hard against the underside of the roofing dampens rain-induced vibration.
Wiring. If insulation is going in, YourHome says wiring must be sized so it won’t overheat when covered, and suggests having it checked by a licensed electrician. Foil must be kept clear of wiring and fittings.
Choosing the steel
Distance from the sea matters. Colorbond recommends Colorbond steel for roofs more than 200m from breaking surf, and Colorbond Ultra steel between 100m and 200m. It suggests contacting BlueScope for severe or heavy industrial conditions.
Some metals don’t mix. BlueScope says lead flashings shouldn’t touch Colorbond or Zincalume steel, and should be painted if water runs off them onto the steel. Copper pipes shouldn’t touch the steel or drain onto it. Old flashings left from a tiled roof need checking for this.
How JSJ can help
Inspections are free for home owners, with no obligation. We look at the roof and send you photos of what we find. We’ll contact you by the next business day to arrange an inspection. After the inspection you get a written quote with photos within 24 hours.
See roof replacement. Not sure yet whether you need a new roof at all? Read repair or replace?
Common questions
Do I need council approval to change a tiled roof to metal?
It depends on your property. The NSW Government says exempt work must meet every relevant standard, can’t be done on land on the State Heritage Register, and may be limited in heritage conservation areas. The City of Sydney requires an exemption request for works affecting a heritage item or a building in a heritage conservation area. Check with your council before you start.
Can any tiled roof be changed to metal?
Not always without changes. Monier, a roof tile maker, says a roof’s pitch and structure were designed for a specific material, and switching to lightweight roofing could need engineering advice. Each metal profile also has a minimum pitch, Lysaght says.
Is a metal roof noisier in the rain?
It can be. Lysaght says rain on a steel roof can sound louder than on tiles, and that insulation, sarking and ceiling treatments manage this.
What goes under a metal roof?
YourHome says to use sarking or foil-backed insulation under metal roofs, and recommends a vapour barrier there to reduce condensation and corrosion. It says best-practice roofing uses vapour-permeable membranes.
I live near the beach. Which steel should I use?
Colorbond recommends Colorbond steel more than 200m from breaking surf, and Colorbond Ultra steel between 100m and 200m. For closer or harsher sites, it suggests contacting BlueScope for advice.
Is the inspection free?
Inspections are free for home owners, with no obligation. You don’t need to be home.
Sources
Checked 1 November 2026. Rules and policies change, so check the source for the current position.
- Exempt development (NSW Government (Department of Planning))
- Understanding exempt development (fact sheet, 2022) (NSW Department of Planning and Environment)
- Gain exemption from requiring development consent for heritage works (City of Sydney)
- Inner West Development Control Plan, Part 2.12 Heritage (Inner West Council)
- Roof restoration (Monier (CSR))
- Roofing and walling installation manual (Lysaght (BlueScope))
- Why Colorbond steel delivers smarter value for roof replacements (19 November 2025) (Lysaght (BlueScope))
- Condensation (YourHome (Australian Government))
- Insulation installation (YourHome (Australian Government))
- Why choose metal roofing? Benefits and key considerations (25 September 2025) (Lysaght (BlueScope))
- Colorbond steel roofing (Colorbond (BlueScope))
- Avoid incompatible metals (BlueScope Steel)