Why This Matters to You
If your house was built or renovated between roughly 1995 and 2010, you very likely have halogen downlights, and there's a good chance nobody has ever told you what they're costing you.
A single halogen downlight draws around 50 watts. Thirty of them, which isn't unusual in a family home across Golden Grove, Greenwith or Gulfview Heights, is 1,500 watts. That's more than a decent air conditioner, running every evening.
But the power bill is only half of it. The bigger issue is heat, and what that heat has done to your insulation.
The Insulation Problem Nobody Mentions
Halogen downlights run hot. Genuinely hot, hot enough that older fittings needed a physical clearance from insulation to avoid becoming a fire risk.
So when the insulation was installed, it was pulled back in a ring around every single light. Go into your roof space and look. In a house with thirty downlights you have thirty holes in the insulation layer, each one a direct path for heat to escape in winter and pour in during summer.
You paid for insulation, and then cut holes in it. The heating and cooling cost of that's real, and it's quietly larger than the lighting bill it came with.
It's also a live fire risk in houses where somebody has since topped up the insulation without knowing about the clearance requirement, and simply laid it over the top. That does happen, and it's one of the things we look for when we're in a roof space.
What Changes With LED
An LED downlight producing similar light draws somewhere between 7 and 12 watts. That's roughly an 80 per cent reduction in your lighting load.
More importantly, LED fittings rated and marked for insulation contact can be covered directly. That means the insulation can be laid as a continuous layer instead of thirty separate cut-outs, which restores the thermal performance you originally paid for.
Modern LED downlights also last far longer, typically tens of thousands of hours against a couple of thousand for halogen, so the constant ladder work to replace blown globes stops as well.
Why Swapping the Globe doesn't Work
You can buy an LED lamp that fits into an existing halogen can. We don't recommend it, and here's the honest reason.
The original can is still in your ceiling, so the insulation clearance requirement is still there. You haven't solved the insulation problem at all. The original transformer is also still there, and halogen transformers were designed for a much higher load than an LED draws. That mismatch is where flickering, buzzing and premature failure come from.
So you spend money, keep two of the three problems, and often introduce a new one. Replacing the complete fitting costs more up front and is the version that actually delivers the outcome.
Do the Layout Properly While You're There
Most downlight layouts we come across were done as a grid. Evenly spaced across the ceiling, which gives flat light and puts bright spots in the middle of rooms where nobody stands.
Since we're replacing every fitting anyway, it's worth thinking about where the light should actually go. Over benches rather than centred on the kitchen ceiling, so you aren't standing in your own shadow while chopping. In front of wardrobes rather than behind you. Washing walls rather than lighting floors.
It costs very little extra to move a fitting while the ceiling is already open, and the difference in how a room feels is much larger than the difference in the bill.
Get the Colour Temperature Right
Around 3000K reads as warm and suits living areas and bedrooms. Around 4000K reads neutral and works better in kitchens, laundries, bathrooms and garages where you want to see detail.
The one thing worth avoiding is mixing temperatures within a single open-plan space. It reads as a mistake rather than a choice, and it's very obvious once you notice it. Some fittings are switchable, so the decision can be made on site.
If You Want Dimming, Say So Before We Quote
LED dimming is where these jobs most often go wrong. Not every LED downlight is dimmable, and among those that are, not every one works with every dimmer. The wrong combination gives you flicker, buzzing, a narrow dimming range, or lights that refuse to go below half.
There's also a specific trap: replacing halogens with LEDs on an existing dimmer usually won't work, because old dimmers were built for a much higher minimum load than LEDs draw. That dimmer needs replacing along with the lights.
None of this is difficult if it's planned. It's only a problem when dimming gets mentioned after the fittings are already chosen.
Is It Worth Doing
If you have more than about fifteen halogen downlights and you're still living in the house in three years, yes, comfortably. The lighting saving alone is meaningful, and the insulation improvement is the part most people underestimate.
If you have a handful of halogens in a room you rarely use, it's less compelling on economics alone, though it's still worth doing when you're having other work done and someone is already in the roof space.
