Anyone who has applied for a building permit in Victoria since May 2024 has run into the state’s 7-star energy efficiency requirement, and window treatment is where a lot of the compliance headache actually lands. The rule itself sounds simple. Meeting it on a real block of land with real orientation constraints is a different story.
The Department of Energy, Environment and Climate Action is explicit that double glazing is not mandatory under the new standard, but notes that most homes will require high performance glazing to some degree to hit the required thermal rating. Builders are left to make up the shortfall through a combination of insulation, orientation, and external shading, and shading is often the cheapest lever available once a design is already locked in.
That last point is where a lot of renovators and self-builders end up, sometimes later than they should. Draftspeople have started flagging external window coverings during the design phase specifically because retrofitting shading after a NatHERS assessment has already been submitted creates unnecessary rework. Homeowners who want to compare options before that assessment is locked in often shop Northern Shutters ranges alongside two or three other Melbourne suppliers to see which products are already NatHERS-friendly.
Why External Shading Outperforms Glazing Upgrades on a Cost Basis
Upgrading an entire home from single to double or triple glazing is expensive, often running into tens of thousands of dollars once frames and installation are factored in. External shutters achieve a meaningful chunk of the same thermal benefit for a fraction of the cost, and that’s why energy assessors keep recommending them as a first move rather than a last resort.
The logic holds up under scrutiny. Glazing manages heat transfer through the glass itself, but shading stops solar radiation from reaching the glass in the first place, and preventing heat gain is consistently cheaper than managing it after the fact. For homes with large west or north-facing window expanses, that difference compounds quickly across a Melbourne summer.
Energy assessors working through NatHERS software have started running comparative scenarios for clients showing exactly how much star-rating improvement shading contributes versus glazing alone, and the numbers tend to surprise people who assumed double glazing was the only real lever available.
What Homeowners Are Actually Installing to Hit the Rating
On the ground, the practical response has been a mix of retrofits and new-build specifications, with aluminium roller shutters showing up more often in energy assessment reports than they did even two years ago. They are relatively simple to model in NatHERS software, which makes them an attractive option for assessors trying to close a small ratings gap without redesigning a whole facade.
Homeowners planning a renovation this year have also started requesting quotes earlier in the process, aware that shading needs to be locked in before a final energy assessment rather than bolted on afterward. Suppliers report longer lead times as a result, particularly for custom sizing on older housing stock where standard shutter dimensions do not fit cleanly.
The Compliance Trap Renovators Keep Falling Into
The most common mistake, according to assessors, is treating window coverings as a cosmetic decision made after the energy rating has already passed, rather than a compliance tool used to help it pass in the first place. Once a permit is submitted, changing the thermal strategy becomes a paperwork exercise nobody wants to repeat.
Builders who get this right tend to loop shading suppliers into the design conversation early, well before slab is poured. It is a small procedural change that saves weeks of back-and-forth later, and it is becoming standard practice across renovation projects in Melbourne’s growth corridors as the 7-star requirement beds in.