After nearly two decades in commercial lighting, I’ve seen projects go wrong in predictable ways. The good news is these mistakes are avoidable. Here are the five I encounter most often.

Mistake 1: Choosing LEDs Based on Wattage Alone

This one drives me crazy. A client will say “we’re replacing 400W metal halides, so let’s get 400W LEDs.”

No. Stop. That’s not how this works.

LED efficiency has improved dramatically. A modern 150W LED highbay can match or exceed the light output of a 400W metal halide. Going watt-for-watt means you’re massively over-lighting the space and wasting money on both fixtures and electricity.

What to do instead: Focus on lumens, not watts. Work out how much light you actually need for the space (lux levels for the task), then specify fittings that deliver that output efficiently.

For a warehouse storing goods? 200 lux at floor level is probably plenty. For detailed assembly work? You might need 400-500 lux. The Australian Standard AS/NZS 1680 gives guidance on illumination levels for different applications.

A competent lighting supplier should provide a basic lighting design showing predicted lux levels. If they’re just selling you boxes without checking the application, find a different supplier.

Mistake 2: Ignoring Colour Temperature

Metal halides have a warm white colour (around 3000-4000K typically). Some old fluorescents are quite warm too. Then someone installs 6500K “daylight” LEDs because they’re marginally cheaper or more efficient on paper.

The result? Complaints. Lots of complaints. The space looks harsh and clinical. Staff don’t like it. Sometimes clients even ask to remove the new LEDs—after the project is finished and paid for.

What to do instead: Match or intentionally improve on the existing colour temperature. For most commercial applications:

• Warehouses and industrial: 4000K or 5000K works well
• Offices: 4000K is standard, 3500K if you want warmer
• Retail: Depends heavily on what you’re selling (warm for furniture and fashion, cooler for tech)
• Healthcare: Usually 4000K, but specific areas have specific requirements

Get a sample fitting before committing to a large order. Install it in the actual space and look at it. Five minutes of testing beats weeks of regret.

Mistake 3: Forgetting About Glare

Some LED fittings are uncomfortable to look at. This matters more than people realise.

In an office, glare causes eye strain and headaches. In a warehouse, workers looking up at blinding points of light is a safety issue. In retail, glare can ruin the shopping experience.

What to do instead: Check the fitting’s UGR (Unified Glare Rating) for offices and similar environments. AS/NZS 1680.1 specifies maximum UGR values for different tasks. For industrial highbays, look for fittings with proper diffusers or optical designs that spread light evenly.

Again, seeing samples in place before committing is invaluable. Technical specifications only tell part of the story.

Mistake 4: DIY Rebate Claims

“How hard can it be? We’ll just fill out the forms ourselves.”

Famous last words. I’ve watched clients attempt to navigate the ESS or VEET paperwork without an experienced Accredited Certificate Provider, and it rarely ends well.

The calculation methodologies are specific and technical. The evidence requirements are precise. The scheme administrators reject applications for seemingly minor discrepancies. And if you make mistakes, you might miss the deadline windows for claiming certificates on your installation.

What to do instead: Work with an ACP from the start. Yes, they take a margin on the certificates. But they know exactly what evidence to collect, how to structure the application, and how to handle queries. The certificates they secure almost always exceed what a DIY attempt would achieve.

I’ve seen clients “save” a few thousand in ACP fees and lose tens of thousands in certificates that should have been eligible but weren’t properly documented.

Mistake 5: Treating All Spaces the Same

A warehouse isn’t an office isn’t a car park isn’t a retail floor. But I’ve seen projects where someone ordered one type of LED fitting and installed it everywhere because it was simpler.

Different spaces have different needs:

• Warehouses: Highbays with appropriate beam angles for the racking layout
• Offices: Panels or troffers with good UGR ratings
• Car parks: Vandal-resistant fittings with appropriate IP ratings
• External areas: Weatherproof, often with specific colour temperatures for safety
• Emergency exits: Must meet AS 2293 requirements

What to do instead: Zone your project by space type. It might mean ordering from multiple product lines or even multiple suppliers. The small additional complexity is worth it for a fit-for-purpose result.

A Bonus Mistake: Skipping the Post-Installation Check

Project finished. Rebate claimed. Invoice paid. Done, right?

Not quite. Schedule a walkthrough 2-4 weeks after installation. Look for:

• Any fittings flickering or failed
• Areas that are too bright or too dim
• Complaints from occupants you haven’t heard about
• Control systems actually being used correctly

Address issues while they’re under warranty and while your contractor is still engaged with the project. Discovering problems six months later is much harder to resolve.

The Common Thread

These mistakes share a common cause: rushing into the procurement phase without proper upfront planning.

A good LED retrofit project starts with understanding the existing situation, defining what success looks like, and then selecting products and partners that will deliver that outcome.

It’s not complicated. But it does require slowing down at the beginning to save time, money, and frustration later.

If you’re planning a significant retrofit and want an independent review before committing, that’s a service many lighting consultants offer. Sometimes a few hundred dollars in professional advice prevents tens of thousands in poor decisions.

Or just remember these five points and learn from other people’s expensive lessons. Your choice.