High-voltage power in ERP/IGH buildings: compliance and halogen-free FRN1 cables
ERP framework: articles EL.4 to EL.16, NF C 15-100 §560, decree of 25 June 1980
The FRN1 cable is not a premium option: it is the only enforceable standard for ERP/IGH buildings under the decree of 25 June 1980 (category C2). Any high-voltage power quote that proposes standard PVC on an ERP/IGH floor plate is legally non-compliant, regardless of the 15 to 25% material premium sometimes cited to justify deviating from it. On a 500 to 1,000 m² office floor plate hosting sixty to one hundred workstations, the subscribed power generally ranges between 50 and 100 kVA, with a projected load of around 60 to 70% that must factor in ERP selectivity, IGH safety power sources and FRN1 cables right from the single-line diagram. Kytom coordinates the electrical engineering office, the technical inspector and the SDIS from the initial audit through to the issuance of the Consuel certificate.
The ERP safety regulation sets out three structuring high-voltage power obligations: normal and safety power sources (EL.4 to EL.7), selectivity of protections (EL.10), fire-rated isolation of electrical conduits (EL.16). NF C 15-100 §560 specifies the requirements applicable to safety lighting, electrical smoke extraction and safety installations.
Obligations to factor in from the design stage:
- Category 1 to 4 ERP buildings (types R, U, J, L): selectivity demonstrated through Icc calculations and a backup power source tested monthly.
- Amended decree of 25 June 1980: cables with improved fire behaviour (category C2) on safety lighting, mechanical smoke extraction and priority lifts.
- 2026 site single-line diagram: standardised identification, insulation testing by batch, FRN1 material traceability.
| Standard | Scope | Kytom deliverable |
|---|---|---|
| NF C 15-100 §560 | Safety lighting, smoke extraction | Calculation note |
| EL.4 to EL.16 | Power sources and selectivity | Single-line diagram |
| Decree 25/06/1980 | C2 LSZH cables | Material schedule |
The Kytom team documents compliance line by line in the DOE handed over to the project owner. Application limit: the category 1 to 4 ERP framework is not relevant below 300 m² or for occupancy of fewer than 19 people (5th-category ERP without sleeping accommodation). Total selectivity and monthly-tested backup power sources become disproportionate to the risk. At these sizes, Kytom recommends a standard NF C 15-100 compliance upgrade with FRN1 on safety lighting only, for a material premium that is generally limited on the electrical package.
IGH framework: article GH 36, technical instruction IT 246, total selectivity at the main LV switchboard
The amended decree of 30 December 2011, article GH 36, tightens requirements on three fronts: redundancy of safety power sources, fire-rated isolation of vertical service shafts, signage for safety equipment. Technical instruction IT 246 frames mechanical smoke extraction with its high-voltage power implications, notably dedicated supplies and fail-safe operation.
Requirements specific to class A to Z IGH buildings:
- Total selectivity between the main LV switchboard and the distribution boards, verified through Icc calculations and coordination tests.
- Fire-resistant CR1 cables on priority circuits (smoke extraction, priority lifts, EAS).
- Halogen-free FRN1 cables across the entire high-voltage power distribution, including the 16A sockets per floor and their backed-up equivalents.
The operations technical teams validate the general shutdown and switchover-to-safety-source tests before commissioning. Kytom coordinates the electrical engineering office, the approved technical inspector and the SDIS, and schedules acceptance tests to prevent any schedule slippage.
Contrary to an extensive reading of the IGH standard sometimes promoted by certain engineering offices, applying the GH 36 standard to a non-IGH R+6 building (top-floor slab height < 28 m for offices or < 50 m for housing) does not strengthen safety, it inflates the bill. Over-sizing the main LV switchboard can represent a significant share of the electrical package cost, with no measurable safety benefit in return. The right standard then remains category 1 to 4 ERP.
For the Asset Manager: what high-voltage power non-compliance really costs on the balance sheet
The FRN1 issue is not just a technical trade-off between cable types. For an Asset Manager who owns an ERP or IGH office asset, three lines of the operating account are exposed by non-compliant high-voltage power distribution.
1. Asset value and liquidity. An unfavourable safety committee opinion or an undelivered Consuel certificate blocks commissioning, delays lease take-up and weakens valuation at resale. On a mid-sized office asset, a few weeks of administrative delay can represent significant lost rental income, to be compared with the FRN1 material premium, which remains marginal in the overall works cost of the electrical package.
2. Civil and criminal liability of the project owner. Articles EL.4 to EL.16 are enforceable. In the event of an incident, the absence of compliant C2 cables engages the owner’s liability under article R143-2 of the construction and housing code, regardless of the installer’s quality of work.
3. Insurability. Several construction defects and multi-risk building insurers now require the FRN1 material schedule on ERP/IGH buildings at the underwriting stage. Standard PVC distribution not identified in time triggers a premium revision or a partial exclusion.
The Kytom view: systematic FRN1 in ERP/IGH buildings is not an expense, it is a risk cover whose marginal cost pays for itself in the first month of secured rent.
FRN1 versus PVC: smoke density divided by 5 to 10, material premium of 15 to 25%
Traditional PVC releases hydrogen chloride (HCl) as it burns. This toxic gas reduces visibility along evacuation routes and corrodes metal structures, slowing down the evacuation of occupants and hampering emergency response. FRN1 cables (Low Smoke Zero Halogen) meet the C2 classification of NF C 32-070: flame-retardant, low-opacity smoke, no toxic halogenated gas.
Measured operational gains:
- Smoke density reduced by a factor of 5 to 10 in the event of fire, in accordance with the NF EN 61034-2 tests adopted in NF C 32-070 category C2.
- Extended evacuation time along protected routes.
- Protection of sensitive electronic equipment (server racks, BMS, access control).
| Criterion | Standard PVC | FRN1 LSZH |
|---|---|---|
| Halogen | Present (HCl) | Absent |
| Smoke density | High | Divided by 5 to 10 |
| Material premium | Reference | +15 to 25% |
| ERP/IGH C2 compliance | No | Yes |
The FRN1 material premium compared to standard PVC generally sits between 15 and 25% depending on the sections (1.5 to 25 mm²), a gap offset by the reduction in insurance risk and alignment with enforceable ERP/IGH requirements. Kytom specification standard: systematic FRN1 on all ERP/IGH high-voltage power delivered since 2026.
Non-application condition: in an enclosed technical room that is not an ERP (waste room, non-IGH landing shaft), standard PVC remains acceptable under NF C 15-100 and the FRN1 premium is not justified.
Frequently asked questions
Is FRN1 mandatory on all circuits of an ERP building?
The order of 25 June 1980 requires category C2 (FRN1) on safety circuits: emergency lighting, mechanical smoke extraction and priority lifts. Since 2026, Kytom has extended this requirement to all ERP/IGH high-voltage wiring to standardise the bill of materials: conventional PVC releases toxic fumes and is not C2-compliant on these floors. The 15–25% material premium remains marginal relative to secured rent.
