If you’re weighing up an LED lighting upgrade for a warehouse, factory, shop, or office in Auckland, one of the first questions is usually the same: do you retrofit your existing fittings, or replace them outright? The right answer depends on the condition of what you’ve already got, your budget, how much downtime you can tolerate, and how long you’re planning to stay in the building. This guide walks through how that decision actually gets made, what genuinely affects your savings, and what to check before committing either way.
This is a companion guide to our lighting service pages — for the practical detail on each type of space, see LED Lighting and Upgrades, Building, Factory, and Warehouse Lighting, and Lighting Installation, Maintenance, and Upgrades.
Retrofit or full replacement: what’s the actual difference?
Retrofitting means keeping your existing fixture housing — the part bolted to the ceiling or wall — and replacing what’s inside it: the lamp, and often the driver or ballast, with an LED equivalent. It’s generally the faster, lower-disruption, lower-cost option, and it makes sense when the housings themselves are in good physical condition and correctly positioned for how the space is used.
Full replacement means taking out the entire fixture and installing a new LED luminaire in its place. This is the better option when the existing housings are old, damaged, corroded, or simply the wrong type or layout for the space — for example if you’re changing from widely spaced high-output fittings to a different distribution pattern, or the wiring and mounting points need to be redone anyway.
How to decide which one you need
- Condition of existing fittings. If housings are sound, retrofit is usually the more cost-effective route. If they’re damaged, rusted, or near end of life, replacement avoids paying twice.
- Fit and layout. As we note on our LED page, a key question is whether new LED components will fit into the existing fitting holes, or whether they’ll need separate mounting — this alone can tip the decision toward replacement.
- Downtime tolerance. Retrofits are typically faster to install fitting-by-fitting, which matters if the space needs to stay operational.
- Length of tenancy. If you’re on a short lease, a lower-cost retrofit with a shorter payback horizon may make more sense than a full fit-out.
- Warranty and product quality. A retrofit is only as good as the driver and lamp going into an old housing — it’s worth asking what warranty applies to the LED components themselves, separate from the (unchanged) housing.
What actually determines your savings
You’ll see energy-saving percentages quoted all over the lighting industry, and they vary a lot — because the real number depends entirely on what you’re replacing. LED lighting can use around 85% less electricity than old incandescent or halogen bulbs, which is where the highest commonly-quoted figures come from. But most Auckland commercial and industrial buildings aren’t running incandescent lighting any more — they’re running older fluorescent tubes or metal halide high-bay fittings, where the realistic reduction is typically in the 40–70% range, depending on the age and type of the existing system and how the new fittings are specified.
Rather than relying on a generic percentage, the most reliable way to know your actual savings is to measure your real before-and-after consumption. If a lighting upgrade is part of a broader look at your electrical load, our power logging service can establish a genuine baseline before work starts, so any improvement after the upgrade is a measured number for your building, not an industry-wide estimate.
Lighting levels and standards
Workplace lighting design in New Zealand is generally guided by the AS/NZS 1680 series of interior and workplace lighting standards (jointly published with Australia), which covers general principles as well as specific applications including industrial tasks. Separately, under the Health and Safety at Work Act 2015, businesses have a general duty to provide a safe working environment, which WorkSafe New Zealand’s own guidance on workplace facilities identifies as including adequate lighting for the tasks being carried out.
What this means in practice: the right lighting level isn’t one-size-fits-all. A rarely-used storage area, a busy picking aisle, and a fine-detail workbench all call for different amounts of light. Rather than assuming a single fitting or wattage suits your whole building, it’s worth having the specific zones in your space assessed against the task being performed in each one.
Warehouse and factory-specific considerations
High-ceiling spaces bring their own set of decisions on top of the retrofit-vs-replace question — see our dedicated page on Building, Factory, and Warehouse Lighting for the detail. In brief, high-bay fittings need to be specified for mounting height and beam spread so light actually reaches the working plane evenly, rather than just being bright directly underneath each fitting. Areas that are only occasionally occupied — the back of a warehouse aisle, for example — are also often good candidates for motion or daylight sensors, which can reduce running hours independently of the fitting itself.
Don’t forget maintenance planning
LED lamps last a long time — often quoted at up to 50,000 hours, which works out to roughly a decade under typical daily use — but “long life” isn’t “no maintenance”. Drivers can fail independently of the lamp, fittings still need cleaning to maintain output, and a mixed-age installation (some LED, some legacy) is worth tracking so you’re not caught out replacing fittings piecemeal at inconvenient times. See Relamping of Auckland Facilities for how a planned relamping programme keeps this predictable rather than reactive.
Frequently asked questions
Is retrofitting always cheaper than full replacement?
Usually, but not always. If your existing housings are damaged or the wrong layout for how the space is used now, a retrofit can end up costing more in the long run than doing the job properly with new fittings once. It’s worth having both options costed before deciding.
How much will I actually save by switching to LED?
It depends on what you’re replacing. Savings compared with old incandescent or halogen lighting can be as high as 85%; compared with fluorescent or metal halide high-bay fittings, which is what most Auckland commercial and industrial buildings are actually running, a realistic range is closer to 40–70%. Measuring your own before-and-after consumption is the only way to get an exact figure for your building.
What standard covers workplace lighting levels in New Zealand?
The AS/NZS 1680 series covers interior and workplace lighting design, including a part specific to industrial tasks. Businesses also have a general duty under the Health and Safety at Work Act 2015 to provide adequate lighting for the work being carried out.
Do LED fittings need any maintenance?
Yes. While LED lamps last far longer than older technology, drivers can still fail independently of the lamp, and fittings need periodic cleaning to maintain their output. A planned relamping schedule keeps this predictable.
Get a straight answer for your building
Every building is different, and the retrofit-vs-replacement decision really does come down to the condition of what you’ve already got. Legacy Electrical can assess your existing fittings and give you a straightforward recommendation, whether that’s a retrofit, a full replacement, or a mix across different areas of your site. Email service@legacyelectrical.co.nz or contact Alex on 022 108 1177 to talk through your space.