Commercial energy retrofit: compliance, ROI and the Kytom method

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.

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.

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.

1. 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.
2. 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.
3. 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.
4. 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.