IC-4 downlights: what the mark on the fitting means, and why it decides your insulation

The classification is printed on the fitting itself, usually on the body or the trim ring, and sometimes only on the label inside the box. It comes from the Australian and New Zealand standard for recessed light fittings, and each mark answers one question: what can the insulation do near this light?

IC-4. Insulation may touch the sides and cover the top, and the fitting is sealed so air cannot move between the room and the roof space. It is tested with a fine probe to make sure nothing can reach a hot part. This is the fitting for any home that has, or will have, ceiling insulation.

IC. Insulation may touch and cover it, but the fitting is not sealed. Some air still moves through it, which means some of the heat you paid for still leaves through the ceiling. It qualifies as a fitting that can be covered; it is simply not as good as IC-4.

CA90 (and CA80). Insulation may abut the sides but must not cover the top. In practice that leaves a hole in the blanket above every fitting.

Non-IC. Made for commercial ceilings. Insulation must be kept clear on every side. The standard says these do not belong in a home where insulation may be installed now or in the future.

No mark at all. Treated as a fitting that cannot be covered. An insulation installer keeps the default clearance around it, and the standard says an unmarked recessed light should not be installed in the first place.

Plenty of downlight pages in Melbourne describe IC-4 as 'insulation contact, fire rated'. It is not. The rating is defined by a fine-probe test and by whether air can pass through the fitting; fire resistance is not part of the test at all. What IC-4 tells you is that the fitting runs cool enough to be buried in insulation and that it is sealed against airflow. A fire-resistant ceiling is a separate matter altogether and is not something a downlight rating claims to deliver.

IC-F is the other term that gets mixed in. It comes from a New Zealand amendment to the same standard and describes a closed fitting with added resistance to heat, fire and tracking. It is not the Australian classification, you will not find it on a fitting sold for an Australian ceiling, and anyone asking you to source IC-F downlights in Melbourne is using a New Zealand term for an Australian job.

Why does the wording matter? Because a homeowner who has been told their new fittings are 'fire rated' may assume more than the fitting can do, and because an insulation crew reads the mark, not the sales pitch. When we specify IC-4, we mean exactly what the standard means: the batts can lie against it and over it, and the roof space stays sealed from the room. Nothing more, and nothing less.

Ceiling insulation works as a continuous blanket. Every fitting that cannot be covered forces the installer to cut a hole in that blanket and keep insulation clear around it. In a living room with a dozen halogens, that is a dozen chimneys of bare plaster, each one leaking warm air into the roof in July and letting roof heat pour into the room in January. The room feels under-insulated because it is.

Swap those fittings for IC-4 LEDs and the holes disappear. The insulation runs edge to edge, the fittings are sealed so the room air stays in the room, and the old transformers, which needed their own clearance, are gone. This is why we treat downlights as the first half of an insulation job rather than a separate trade: if you insulate first and change the fittings later, the crew has to come back and fill in the gaps.

One detail that most pages skip: the IC-4 mark covers the light fitting, not always the small driver box that powers it. The instructions for many fittings ask for the driver to sit above the insulation with a clearance around it, and our electricians follow the instructions for the fitting they install. If you are checking a ceiling someone else has done, look at where the drivers are, not just the lights.

Our downlights and insulation safety guide goes deeper on the clearances for fittings that cannot be covered.

From 1 October 2026 the Victorian Energy Upgrades ceiling-insulation discount opens to every home in the state. A home whose ceiling contains fittings that are not IC or IC-4 rated is not eligible. In practice, a ceiling of old halogens or unmarked fittings has to have them changed before the discounted insulation can go in. Our home insulation page explains the rest of the program, and the office arranges the discount through our accredited installation partners.

Checking a fitting from the room. Look up at it with the light off. A halogen shows a small glass lamp with a visible reflector sitting inside a metal can, with a transformer on a lead behind it in the roof; that fitting cannot be covered. An integrated LED shows a flat diffused face with no separate lamp, and its classification is printed on the body, which is only readable from the roof side. Do not pull the fitting down yourself; a photo from below is enough for the office to tell you what you have.

Checking from the roof space. If it is safe to look, you will see the story at a glance: batts cut back in a circle around each fitting means the installer treated them as non-IC; batts lying over the fittings means someone decided they were IC or IC-4, which is worth confirming.

Or let us look. Tell the office how many fittings and what they look like, and we give you a free estimate over the phone for the swap. If you are also insulating, the two jobs are booked together, and every job ends with photos of the ceiling and the roof space so you can see the batts running over the new fittings.