LED downlight buying guide: what actually matters

LED downlights are now the default lighting in most Australian homes, and there are hundreds of options on the shelves. Some are excellent. Some look fine in the box and disappointing on the ceiling. The difference usually comes down to a handful of specifications that are easy to understand once someone explains them.

Here’s what we look at when choosing downlights for a client, and the mistakes we most often get called in to fix.

Colour temperature: warm, natural or cool

Colour temperature is measured in kelvin (K) and describes how warm or cool the light looks.

• Around 3000K (warm white) gives a soft, yellowish light similar to old halogens. It suits living rooms, bedrooms and anywhere you want a relaxed feel.
• Around 4000K (natural or neutral white) is crisper without being clinical. It suits kitchens, laundries, bathrooms and home offices.
• 5000K and above (cool white or daylight) is bright and blue-ish. It suits garages and workshops, but can feel harsh in living spaces.

Many downlights now have a switch on the driver to select the colour temperature (often called tri-colour or CCT selectable). They’re a sensible choice if you’re unsure, because you can change your mind after installation. The key is consistency: mixing colour temperatures in one open-plan space looks patchy.

Colour rendering (CRI)

CRI measures how accurately a light shows colours, on a scale up to 100. Cheap LEDs with a low CRI can make skin tones look grey, timber look flat and food look unappetising. For living areas and kitchens, we suggest a CRI of 90 or above. It’s one of the most noticeable quality differences, and it’s often not printed on budget packaging.

Brightness and beam angle

Brightness is measured in lumens, not watts. A higher lumen figure means more light, but more isn’t always better. Too many bright downlights make a room feel like a shop. It’s usually better to use a sensible number of good-quality lights, spaced evenly, with dimming where you want mood lighting.

Beam angle affects how the light spreads. A wide beam gives even, general lighting. A narrower beam creates pools of light, useful for highlighting benches, artwork or a feature wall. Most general-purpose residential downlights have a wide beam.

IC-4 rating and ceiling insulation

This one is about safety, not looks. Downlights generate heat, and older halogen fittings were a known fire risk when covered by ceiling insulation. Modern LED downlights with an IC-4 rating are designed so they can be in contact with and covered by building insulation.

We recommend IC-4 rated downlights for any ceiling with insulation, which in South East Queensland is most of them. It keeps the insulation working as designed and removes the need for clearance gaps that let heat into the house. If you’re replacing old halogens, it’s also a good time to check the roof space for disturbed or missing insulation.

Dimmers and compatibility

Not every LED is dimmable, and not every dimmer works with every LED. Mismatched combinations cause flicker, buzzing, lights that won’t dim smoothly or lights that won’t turn fully off. When dimming matters:

• Choose downlights marked as dimmable
• Use a dimmer the manufacturer lists as compatible, usually a trailing edge type for LEDs
• Check the minimum load, because some dimmers struggle with only one or two LEDs on the circuit

Smart switches and dimmers add another compatibility layer. If you’re planning smart lighting, it’s worth reading our article on smart home wiring before buying.

Cutout size and replacements

The cutout is the hole in the ceiling. A common size is around 90mm, but it varies. If you’re replacing existing downlights, matching the cutout avoids patching or enlarging holes. Some ranges include adaptor rings for different sizes. We measure before recommending anything.

Old halogen downlights often have a separate transformer sitting in the ceiling. When we swap to LED, we remove the old transformer and fit the correct driver, rather than leaving the old one in place. Leaving an unsuitable transformer connected is a common cause of flicker and early failure.

Bathrooms, outdoors and coastal homes

Downlights in bathrooms, under eaves and in outdoor areas need an IP rating suited to the location. The Wiring Rules set zones around baths and showers, and fittings within those zones must meet specific requirements. Outdoors on the coast, salt air shortens the life of lower-grade fittings. Our article on salt air corrosion covers this in more detail.

Can I install downlights myself?

No. Downlights connect to fixed wiring, and installing them is electrical work that must be done by a licensed electrician in Queensland and NSW. Even plug-base downlights, which connect with a small plug, rely on a socket wired into the fixed wiring, so fitting them is licensed work. It’s also worth knowing that many ceiling spaces in older homes contain old wiring, pests or other hazards.

Common mistakes we fix

• Mixed colour temperatures in the same room
• Low CRI lights that make a new kitchen look dull
• Too many downlights in a row, creating glare
• Non-compatible dimmers causing flicker and buzz
• Non-IC-rated fittings with insulation pulled back, leaving cold and hot spots

Getting it right first time

Good lighting is one of the cheapest ways to make a home feel better. We’re happy to recommend fittings, plan a layout and install them properly. See our lighting installation page for what we do, or have a look at new homes and renovations if you’re planning a bigger project.