Renewed Lamps for Old: The Circular Economy is business as usual for heritage lighting

November 16th, 2023

Renewed Lamps for Old: The Circular Economy is business as usual for heritage lighting

In May 2023, the SLL held a well-attended CPD at Coco Lighting in Essex, giving members a practical look at how light fittings can be re-engineered to TM66 Circular Economy principles, rather than scrapped. One striking example on the bench was a 2m diameter cylindrical opal diffuser, one of several feature lights from the atrium of a large office. Formerly populated with T5 fluorescent lamps, transformation was underway to replace these with bespoke LED linear modules. It wasn’t straightforward; our hosts explained the positions for the T5 lamps had been carefully defined to ensure a uniform wash around the sides and face of the cylinder. An LED source is very different to a fluorescent tube, posing a particular challenge where an omnidirectional light spread is wanted. The proposed solution had to be engineered to ensure the desired effect was achieved.

As we stood around the bench looking at this huge piece of engineering, it seemed not only obvious it should be refurbished, but perverse that it might not have been. The quality of the original fitting stood out. After many years of use, the diffuser material showed no signs of heat or UV damage. The client had no desire to change the lighting or aesthetics of the entrance. If you were to scrap it, something new would be needed, to fit just the right space on the ceiling, not require new structural support behind, and give a similar light level. The original lighting was just right for the space, and now benefits from a much-reduced energy bill and no need for difficult lamp changes.

Whilst a late 20th Century office is unlikely to be considered a heritage building, it may become one in time if it is good enough. What stands out with historic buildings is often the quality of the original build. And this often includes ironmongery, furniture, and the lighting.

Ely Cathedral dominates the skyline of the Fens, and later this century will celebrate 1000 years existence. It remains serving its purpose as a place of worship, yet just like our T5 lighting diffusers needs updating and repair from time to time, to ensure it best meets the demands of our world today. Gas lighting was installed in the mid-19th Century, lasting through to the 1930s[1]. Little remains of the scheme, other than two huge gasoliers, standing either side of the High Altar. First converted to electric lighting in the 1930s scheme, these fittings have seen several alterations to their light sources in the past. They are now being upgraded from tungsten capsule lamps to miniature LEDs in the workshops of Great British Lighting, as part of the current scheme to re-light the cathedral.

TM66 has a good checklist in Section 9.4 for use when looking at the re-manufacture of light fittings. When considering refitting a historic light fixture, heritage conservation principles then also need to be applied. Or in medical terminology, “first, do no harm”. We have to pose the following further questions:

  1. What is wrong with retaining the status quo?
  2. What is the objective of the renewing the fitting? Is it electrically unsafe, too bright, too dim, hard to maintain?
  3. Is it technically achievable, at an economic cost?
  4. What are the risks of transporting it off site? Could it be worked on in-situ instead?
  5. Is the intention to replicate the current lighting effect, or do something different?
  6. Will the refurbished fitting retain sufficient original character? New technology may offer energy efficiency, but so too would adding double glazing to stained glass windows.
  7. Could new technology introduce new risks to the building, say through the heat from drivers where there previously were none?
  8. If a previous intrusive modification has disrupted the original design, can it be re-used, minimising the need for further such modifications?
  9. What consents will be needed for any modifications?
  10. If the fitting is not re-used, what will happen to it? Few clients will want a relic non-functional light fitting on display.

When considering an old light fixture, what are we trying to replicate? If it once had gas mantles, the light would have been a slightly different colour tone, perhaps at odds with modern expectations. Glass diffusers with GLS lamps in would usually have intensity hot-spots close to the bulbs. Does one replicate this with LEDs or go for a uniform wash? Imperfections can make for charm.

Historic England offers some guidance here[2]. Many early electric light fittings were adaptations of gas fixtures, with pipes used for wiring right back through the building. Lighting designers in the 1930s lacked precedent for how to make use of this new technology. One early innovation was just to invert the arms of chandeliers for better light distribution, since an upward burning flame no longer needed to be accommodated. So a degree of adaptation of the fitting can be justifiable in a historic context, to get the best result from the technology.

Back to the Ely gasoliers. Once the principle of re-use was agreed, the next step was to have them carefully dismantled and transported for refurbishment. Here, detailed record-keeping by the Cathedral Archivist was invaluable, with photos on file of the previous disassembly for transport and refurbishment undertaken for the 1990s scheme. Once stripped down and cleaned, a design could be developed to integrate new light sources. Following the principles of previous adaptations, rather than place lights on the old gas spigots themselves, small LED capsules, using magnetic fixings, will be placed around the circular band beneath, to illuminate glass crystals fixed onto the gas outlets in the past. At present the work is underway and the gasoliers will be ready to return to the Cathedral later this year.

Heritage projects come in all sizes and budgets. Retaining elements of lighting can be a cost-effective way to keep character. The Norris Museum in St Ives, Cambridgeshire, was one such example. Totally inadequate for the museum, rows of small glass shade pendant lights hung above dark wooden display cases bathed also in uncontrolled daylight. Nevertheless, it had a quaint charm. Following a successful Heritage Lottery Bid, a full refurbishment was carried out, with new and far superior lighting installed. But we found a home for a few of the salvaged glass pendants, lighting the replica study of the museum’s founder Herbert Norris.

We picture working with traditional materials such as wood and metal when thinking of worthy historic light fixtures. But what if the building is from the mid-20th Century and the material palette includes concrete and asbestos? This was the challenge presented at Grade II* Listed Guildford Cathedral, an interwar design completed in 1965. Light fittings, along with most of the interior surfaces were finished with an asbestos coating but integral to the appearance of the space. So following careful consideration, the wall sconces, pendants and external bulkheads were removed from site by appropriate licensed contractors and stripped of asbestos. Only then could they be properly examined and disassembled, and their refurbishment planned.

In looking back at these examples, we can see that re-engineering of light fittings is nothing new, and that quality design of a product generally leaves us with something worth saving. TM66 provides a poignant new emphasis on this, with a focus on the embodied carbon and other climate costs associated with constantly manufacturing from fresh raw materials. By some estimates World copper reserves could run out within the next 30 years[3]. As for the medieval villagers pulling down redundant castles to use the stones for their houses, it will soon simply be too extravagant to use new metal where existing is readily to hand.

But is it enough? As TM66 recognises, daylight is our most efficient light source. For the first 800 years of its existence, beyond its glorious windows Ely Cathedral had just a few candles or pitch-torches, and these would have only been for task lighting. Even the 1930s electric scheme sought only to light specific areas, emphasising the lighting of people and not the building. Yet as slimmer profile light fittings and other technology have become available, there is a temptation to light every last niche and archway, far beyond what could have been imagined for the original build. For meaningful energy savings, we must not slash the consumption of converted halogen fixtures only to treble the amount of new lighting in the building. Just as the extensive outdoor lighting schemes of the past decades are being critically re-appraised now for their effect on the night sky and ecology, so too indoor schemes must be carefully considered in terms of what we are lighting, and why. We should recognise there can be beauty in darkness and what we choose not to light too.

[1] A brief history of artificial lighting at Ely Cathedral (

[2] Internal Lighting in Historic Buildings | Historic England

[3] TM66 Section 9.3


To view the full published article online, please visit SLL Light Lines Magazine

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Published Article in Society of Light and Lighting's Magazine 'Light Lines'.

Authored by Bruce Kirk and Chris Dicks