Team Retrofit

Commercial energy retrofit: compliance, ROI and the Kytom method

Your commercial asset held for less than 5 years risks losing value if you launch a global -40% retrofit without trade-offs: the IRR exceeds the disposal horizon and the CAPEX becomes a dead-weight cost. Yet the regulatory framework mandates -40% by 2030 for any building larger than 1,000 sqm. Across our recent portfolio, Kytom observes a retrofit budget, net of energy savings certificates (CEE), of between 180 and 420 EUR/sqm depending on the technical scope selected, an IRR of 3.5 to 5.5 years on the LED lighting + BMS combination, and a green premium of 7 to 11% on assets certified BREEAM Very Good.

Since 2006, our teams have orchestrated these programmes across more than 1,200 commercial projects, in line with your holding period. Here is our retrofit offer, our 12-week method for the upstream phase and the gains measured in both asset value and cash flow.

Our retrofit offer

From a standardised energy audit to the year N+1 review: what a Kytom assignment covers

A Kytom retrofit assignment covers the entire chain, from the standardised energy audit to the post-works review at 12 months. We deliver three costed scenarios (low cost, median, 2040 ambition) with CAPEX, OPEX, 10-year IRR and a documented kWh/sqm/year trajectory, followed by a complete works package (preliminary design, detailed design, tender documents) covering HVAC, DALI LED lighting, BMS, insulation and joinery. The CEE structuring is managed in-house via the BAT-EQ-127, BAT-TH-116 and BAT-EN-101 sheets; multi-lot execution is framed by our qualifications. Across our recent portfolio, the retrofit budget net of CEE generally falls between 180 and 420 EUR/sqm depending on the technical scope selected. Our reading by holding period determines the scope: a global programme beyond 8 years, a targeted LED + BMS retrofit over 4 to 8 years, a clean data room file under 4 years. No assignment begins without a contradictory validation of the reference year.

The Kytom method

Four stages anchored on a standardised energy audit locked upstream according to the applicable European framework

Our sequence, proven across more than 1,200 commercial projects since 2006, links four phases. Energy audit compliant with the European audit framework (weeks 1-4): 24-month readings, dynamic thermal modelling, mapping of the 12 items, securing of the reference year. Costed scenarios (weeks 5-8): three variants with 10-year IRR and CEE mobilisation. Design and works package (weeks 9-18): preliminary design, detailed design, tender documents, CEE file locked before contract signature. Execution and commissioning (weeks 19-26): just-in-time management, commissioning, operator training, post-works review at 12 months.

We refuse to start the design before the reference year has been fixed: common practice compresses this phase to save a few weeks, but it is one of the main sources of disputes during the operating phase. Below 400 sqm or in a single lot, a short 10 to 14-week design-build cycle is more relevant; beyond 8,000 sqm, the schedule extends to 36-44 weeks.

Your benefits

IRR of 3.5 to 5.5 years, green premium of 7 to 11% and -4 points of rental vacancy

Our operations delivered with a year N+1 review converge on three measurable effects. Energy bill: savings of 32 to 45% on kWh/sqm/year from year N+1. LED + BMS combination IRR: 3.5 to 5.5 years including CEE, i.e. 60% of the regulatory gain for 30% of the CAPEX. Asset value: green premium of 7 to 11% on premium certified offices, vacancy gap of -4 points vs non-certified comparables.

Cash-flow reading on a 3,000 sqm asset let at 320 EUR/sqm/year: median retrofit at 265 EUR/sqm net of CEE, i.e. 795 k EUR of CAPEX. Energy OPEX gain of 18 to 24 k EUR/year (38% saving on 280 kWh/sqm/year at the 2024 green tariff). Major effect via rent: green premium and lower vacancy secure 70 to 110 k EUR/year of additional rental income. IRR at 5.5 years on OPEX alone, 3.5 years with the rent effect (Kytom 2024 model, to be validated by your broker). Ranges valid for a building initially rated EPC D or worse, operating more than 50 hours/week.

Method

Energy audit compliant with the applicable European framework.
Weeks 1 to 4. Consumption readings over 24 months, dynamic thermal modelling, mapping of the 12 items and securing of the reference year by cross-checking invoices and BMS sub-metering. A deliberately separate phase to guarantee a defensible baseline during regulatory inspections.
Costed scenarios
Weeks 5 to 8. Three variants (low cost, median, 2040 ambition) with CAPEX, OPEX, 10-year IRR and kWh/sqm/year trajectory. CEE mobilisation via BAT-EQ-127, BAT-TH-116 and BAT-EN-101 sheets, holding-period trade-off aligned with your asset management horizon.
Design and works package
Weeks 9 to 18. Preliminary design, detailed design and tender documents covering HVAC, DALI LED lighting, BMS, insulation and joinery. The CEE file is locked in parallel with the detailed design, before any contract signature. Traceability on each deliverable.
Execution and commissioning
Weeks 19 to 26. Multi-lot just-in-time management, phasing by floor plates on occupied sites (off-peak hours 6 pm – 6 am, NF S 31-080 acoustic insulation). Commissioning, operator training and post-works review at 12 months on kWh/sqm/year and the achievement of the 80 kWh/sqm.year primary energy threshold targeted by the Effinergie+ renovation label, variable by climate zone and altitude.

Frequently asked questions

From what floor area is a global retrofit economically justified?

A practical threshold of around 600 sqm. Below this, the fixed cost of the standardised energy audit and CEE structuring crushes the IRR beyond 8 years: a short single-lot design-build cycle of 10 to 14 weeks becomes more relevant. Beyond 1,000 sqm, the energy declaration is mandatory.

How is the 3.5 to 5.5-year IRR on the LED + BMS combination calculated?

On medium-sized operations, the IRR of an LED + BMS combination generally falls between 3.5 and 5.5 years depending on whether the rent effect (green premium, reduced vacancy) is included in the calculation, in addition to energy savings alone. The combination captures around 60% of the regulatory gain for 30% of the CAPEX.

What is the real penalty incurred for non-compliance with the energy consumption reduction obligations applicable to commercial buildings?

The fine is capped at 7,500 EUR per building, marginal for an Asset Manager. The real risk is priced in by brokers and AAA tenants. On Kytom assets flagged as non-compliant, the prime rent gap reaches 4 to 7% vs compliant comparables. The trade-off is played out on rental value and liquidity, not on the administrative penalty.

Do CEE really cover 15 to 25% of the CAPEX?

Yes, the standardised BAT-EQ-127, BAT-TH-116 and BAT-EN-101 sheets generally cover a significant share of the works CAPEX (insulation, LED lighting, BMS); the exact amount depends on the eligible volume and the filing timing, which must take place before contract signature. Our CEE unit locks the file in parallel with the detailed design.

05 — Inspirations