LED-retrofit in 2026: wat het per vierkante meter kost en wanneer het zichzelf terugverdient

Als je kantoor zichzelf nog steeds verlicht met tl-buizen, Het debat over de retrofit is voorbij. De vraag die nog rest, is alleen het geld: what does the conversion cost per square metre, and how many months until the electricity savings have paid for it? In 2026 the honest answer for most EU offices is €10–18 per square metre for a like-for-like lamp swap and €16–38 for new luminaires — with typical payback between five and nine years at EU-average electricity prices, inside two years in high-hours rooms like storerooms and basements, and three to six years for whole floors in the high-price member states. There are offices where it lands under two years, and heated, daylit, lightly-used storage where it never will. This article shows the math so you can tell which one you’re in.

The retrofit menu: tubes, kits, or new luminaires

Three options, three price brackets.

Option A — plug-and-play LED tubes. You keep the existing fluorescent fixtures and swap the tubes for LED equivalents, either ballast-bypass or plug-in. This is the “lumen retrofit” in its purest form: same luminaire, same light output class, a fraction of the watts. It’s labour you barely notice — a plumber-electrician swaps a whole open-plan floor in a weekend.

Option B — LED retrofit kits. You keep the luminaire shell, gut the ballast, install an LED module and driver. Cleaner electrically than tubes, similar labour (manufacturers price the swap at about €15 per housing versus €10 for a tube retrofit).

Option C — new LED luminaires. Full replacement panels or linear luminaires, typically priced by installers at €15–20 per point on top of the fixture itself. More expensive, but you get better uniformity, the option of integrated sensors, and a fresh warranty clock.

As reference unit prices: a classic T8 58 W lamp costs around €5.50; LED tube replacements run €19–37 each depending on output class, and LED panels are in the same bracket. Those numbers are from manufacturer comparison sheets with illustrative pricing — your quote will differ — but the ratio between options holds. Swap labour is booked by the same sheets at roughly €10–15 per housing, so each refurbished light point lands at €30–55 all-in, and a full luminaire replacement at €50–90. That density drives the project cost: a T8 office typically carries one light point per 2–3 square metres, or one twin-tube luminaire per 5–8.

And the regulatory clock is on your side for doing nothing only so long: aangezien 1 September 2023, linear fluorescent T8 tubes of 2, 4 and 5-foot lengths must meet a minimum useful efficacy of 120 lm/W under the EU’s ecodesign regulation — a bar the classic 36 W and 58 W tubes fail, which is why they are disappearing from shelves. The socket will outlive the lamp.

How big is the prize? What lighting actually consumes

Two anchors come from published EU-level work. Eerste, the IEA’s Task 50 literature review puts electric lighting at anything between 15% en 60% of final energy use in non-residential buildings, averaging around 35%, and cites measurements of Swedish offices at an average of 21 kWh/m²/year for lighting, met 10 kWh/m²/year as a realistic target for efficient practice. Tweede, the European Commission’s JRC solid-state lighting report shows offices are the single largest lighting consumer in the non-residential sector — around 20% of that sector’s lighting electricity — and documents measured LED retrofits cutting school lighting consumption from roughly 31 kWh/m²/year to under 5.

For payback math we use a realistic middle: an existing EU office at a lighting intensity of 20 kWh/m²/year. That’s below the 21 kWh/m² average measured in Swedish offices but typical of installed T8 practice — and below it the retrofit simply takes longer. Note this figure is dominated by how long the lights burn: 10 W/m² of legacy fluorescent gear running 2,000 hours a year is exactly 20 kWh/m².

The efficiency claim itself is not serious science any more. Gemeten, a simple LED upgrade of an existing fluorescent installation cuts lighting energy by about 63% (LBNL), and the EU ecodesign benchmark for linear LED tubes is 140–160 lm/W — three to four times the efficacy of the tubes it replaces.

What one square metre costs, and what it saves

We price three realistic scopes for a standard open-plan office, using a legacy load of 10 W/m² running 2,000 hours a year — the 20 kWh/m² baseline — at the 2026 EU average business electricity price of €0.18/kWh (Eurostat, companies buying 500–2,000 MWh/year, excluding recoverable VAT; smaller offices on lower consumption bands pay noticeably more, which only shortens payback).

Retrofit scope	Installed cost per m²	Annual saving per m² (€0.18/kWh)	Simple payback
LED tube swap in existing fittings (lumen retrofit)	€10–18	€1.80–2.16	5–8 years at EU-average prices; 3–6 years at €0.25–0.35/kWh
New LED luminaires, no controls	€16–28	€2.52–2.88	6–9 years at EU-average prices
New LED luminaires + presence and daylight control	€22–38	€2.52–3.60	6–10 years open-plan, best case — but under 2 years in high-hours rooms

The saving column comes from 10 kWh/m²/year (a 50% cut of our 20 kWh/m² baseline) for tube swaps and 14–18 kWh/m²/year (70–90%) for luminaires with controls — the controls uplift is what the LBNL systems study measured: simple LED gets 63%, integrated systems with daylight and occupancy control reach 81–93%.

Example, because per-square-metre numbers go numb. A 500 m² office on tube retrofit: investment roughly €5,000–9,000, saving €900–1,080 per year (5,000–6,000 kWh). Full luminaires with sensors: €11,000–19,000, saving €1,260–1,800 a year. A 24/7 storeroom of 80 m² on tubes — 8,760 hours at full intensity — invests about €1,200 and pays itself back inside two years, then throws off over €600 a year: that’s the room to do first.

A degree of honesty about “instant payback”

Sales decks quote 1–2 year paybacks because they pick the best room in the building: a 24/7 storeroom or a windowless basement meeting room with lights on 4,000 hours a year saves three times what a daylit open area does, at the same install cost. The variables that decide where you land:

Operating hours. Payback is almost entirely hours × price. The same 500 m² floor used 1,000 hours a year saves about €450–540; used 3,000 hours it saves over €1,350 — identical bill, one-third the payback.
Legacy power density. The table assumes 10 W/m². Decorative halogen downlights — 35–50 W each, many points per square metre — repay two to three times what a T8 tube swap does at the same LED cost. Those jobs genuinely do pay back inside two years; an efficient-by-accident drop-ceiling grid takes longer.
Daylight. Daylight-linked dimming is where the extra 20 saving-points live. Presence control comes first in rooms that are empty half the day — without it, the luminaires you just paid for still burn at full power.
Electricity price. Use your real €/kWh, not the EU average. Offices paying over €0.25/kWh (Ierland, Germany and Cyprus all reported above €0.22 in H2 2025) cut the payback column by a third or more.
Maintenance you don’t count. LED runs L80/B10 — 80% of initial output at 50,000+ hours — versus re-lamping and ballast calls on fluorescents. Group re-lamping contracts shrink to nothing. It’s real money that never shows in an energy-saving quote.

What to do, in which order

1. Meter the baseline. One month of sub-metered lighting, or a lux meter plus a luminaire count. Every quote you accept should predict your current kWh/m² — if it can’t, it’s guessing. 2. Tube-swap the hours, replace the visible. Put Option A money into rooms with long hours and no daylight value; put full luminaires where ceilings are being redone anyway or where sensors want to live. 3. Do controls on the cellular and common areas, not the open floor. Presence switching pays where rooms are small; daylight dimming pays on perimeter zones. 4. Retire ballast inventory before it retires you. T8 stock is thinning on EU shelves. Lock lamps or run the retrofit while replacement parts are still cheap.

The rule of thumb that survives contact with the data: any room running lights more than 4,000 hours a year, or any floor paying over €0.30/kWh, is a three-to-five-year return you should take this quarter; the rest of the building is a five-to-nine-year return you plan into the next refit. Sequence the rooms, quote the hours, and the audit answers itself.

Bronnen

Eurostat, “Non-household electricity prices fall further in 2026” (H1 2026 EU average €0.18/kWh, band 500–2,000 MWh), 4 Nov 2026: https://ec.europa.eu/eurostat/en/web/products-eurostat-news/w/ddn-20261104-1
Eurostat, Elektriciteitsprijsstatistieken (non-household prices by country and band, H2 2025 €18.37/100 kWh): https://ec.europa.eu/eurostat/statistics-explained/index.php?titel=Electricity_price_statistics
JRC, “Update on Status of Solid-State Lighting & Smart Lighting in the EU” (offices ≈20% of non-residential lighting electricity; measured LED retrofit 31.2 → 4.94 kWh/m² in Greek schools): https://publications.jrc.ec.europa.eu/repository/bitstream/JRC135597/JRC135597_01.pdf
IEA SHC Task 50, “Daylighting and lighting retrofit to reduce energy use in non-residential buildings: A literature review” (lighting 15–60% of final energy use, mean 35%; offices 21 kWh/m²/yr, Doel 10 kWh/m²/yr): https://task50.iea-shc.org/Data/Sites/1/publications/Technical_Report_T50_D2_final.pdf
LBNL, “Energy Cost Savings of Systems-Based Building Retrofits” (simple LED upgrade 63% lighting energy savings; integrated systems 81–93%): https://bies.lbl.gov/sites/default/files/Regnier%20system_vs_compoent_energy_cost_saving_10.2018_0_1.pdf
Commission Regulation (EU) 2019/2020 on ecodesign requirements for light sources (T8 2/4/5-foot minimum 120 lm/W from 1 Sep 2023; LED linear tubes benchmarked at 140–160 lm/W): https://eur-lex.europa.eu/eli/reg/2019/2020/oj/eng
Ledvance, “Alternative lighting options for industrial applications” (illustrative pricing: T8 58 W €5.45, LED tube €21.90–37.30, swap labour €10–15 per housing, L80/B10 ratings): https://www.ledvance.com/00_Free_To_Use/asset-13078150_lamp_ban_applicationflyer_industry_2024_10_-en-.pdf

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Carla Lavigne is Green Ops Editor bij mycompanyisgreen.org en de collega die de rekenmachine meeneemt naar de audit.

LED-retrofit in 2026: wat het per vierkante meter kost en wanneer het zichzelf terugverdient