opinion3 min read

The growing role of retrofit in exterior lighting upgrades

Across the UK, Local Authorities are starting to reassess whether full lantern replacement is always necessary during lighting upgrade programmes.

For years, full lantern replacement was seen as the standard route to LED upgrades, whether replacing legacy HID lanterns or earlier generations of LED lighting. But as councils review ageing lighting assets, many are starting to ask a different question:

Do we actually need to replace the whole fitting?

The exterior lighting market is changing

While some Local Authorities still operate legacy HID lanterns, others moved to LED during the first major wave of upgrade programmes. Many of those early LED installations are now out of warranty, suffering from driver or CMS obsolescence, becoming harder to maintain, or no longer delivering the performance expected from modern lighting systems.

At the same time, many HID lanterns and early LED housings remain in good structural condition despite relying on ageing or outdated internal technology.

That creates a growing middle ground where the lantern itself remains serviceable, but the lighting technology inside no longer meets modern expectations.

Historically, the answer would have been straightforward: replace the lantern.

Now, the conversation is becoming more nuanced.

In many cases, Local Authorities are weighing up not just energy performance, but installation disruption, programme cost, material reuse and long-term maintainability.

Sustainability is changing the conversation

For years, most lighting discussions focused mainly on operational energy. Now, embodied carbon, material waste and asset life are becoming part of procurement and infrastructure conversations too.

Retrofit fits naturally into that thinking. If a quality cast aluminium lantern body still has significant structural life remaining, replacing the entire fitting may not always be the most responsible option.

Budget pressure is also playing a role. Many Local Authorities are balancing ageing outdoor lighting infrastructure, constrained funding and increasing maintenance demands. Retrofit can offer a practical way to improve performance and reduce energy consumption while minimising installation time, traffic management and disruption.

Preserving streetscape character

In many cases, it is not simply about cost. It is also about preserving the character of existing streets and public spaces.

This is particularly true in heritage areas, conservation settings and public realm projects where the lantern itself has become part of the visual identity of the location. In the London Borough of Waltham Forest, for example, existing architectural lanterns were retained as part of a borough-wide retrofit programme because replacing them with standard alternatives would have changed the appearance of the streetscape significantly.

At the same time, the industry’s wider conversation around circular economy principles is starting to reach lighting. Concepts such as reuse, upgradeability, repairability and life extension are becoming more relevant as Local Authorities look for more sustainable approaches to infrastructure management.

Assessing retrofit suitability

Determining whether retrofit is appropriate is not always straightforward.

Factors such as housing condition, ingress protection, optical performance, maintenance history and long-term asset strategy all need to be considered before deciding whether retrofit or full replacement is the most appropriate route.

That is why engineering assessment is becoming an increasingly important part of retrofit programmes, particularly for older decorative or legacy lantern stock.

Retrofit where retrofit makes sense

But retrofit is not always the right answer.

Some lanterns are structurally poor, suffer from significant water ingress, have degraded optics or are simply not suitable for modern performance requirements. In those cases, full replacement remains the better long-term option.

That is why the strongest retrofit approach is not “retrofit everything”. It is retrofit where retrofit makes sense.

As retrofit gains momentum, the market is also likely to become more discerning. Clients will start looking beyond basic gear tray swaps and focus on factors such as photometric performance, IP improvements, ease of installation, long-term reliability and proven application experience.

Retrofit will not replace full lantern replacement programmes. Nor should it.

But it is becoming an increasingly important part of how Local Authorities approach exterior lighting upgrades, particularly where structurally sound assets can continue delivering value for years to come.