Fire-rated frames for commercial offices
EI 30 to EI 120: four fire-resistance ratings governed by the harmonised European classification of construction products
EI 30 covers the majority of linear metres in commercial buildings: over-specifying to EI 60 adds 180 to 240 EUR/m² without any regulatory benefit. In category 5 public-access buildings (ERP), NF EN 13501-2 and the order of 25 June 1980 set EI 30 for standard partitioning between enclosed offices. EI 60 becomes the rule in category W high-rise buildings (IGH) for separations between functional compartments. EI 120 remains reserved for strategic walls in high-rise buildings and main service shafts. These ratings are certified by a test report valid for 5 years (order of 22 March 2004 as amended, article 5). On operations delivered by Kytom since 2006, our commercial projects consistently obtain approval at the first visit of the safety commission.
The fire safety regulations applicable to public-access buildings (ERP, order of 25 June 1980) and to high-rise buildings (IGH, order of 30 December 2011) impose fire-resistance ratings for separating walls. Performance breaks down into three standardised criteria: R (mechanical resistance), E (integrity against gases and smoke), I (thermal insulation). A glazed fire-rated office frame typically falls under the EI criterion, expressed in minutes.
Common ratings in commercial real estate:
- EI 30: category 5 public-access buildings, standard partitioning between enclosed offices.
- EI 60: category W high-rise buildings, separations between functional compartments.
- EI 90: areas with particular risk, archives, technical rooms.
- EI 120: walls between high-rise building compartments, main service shafts.
The test report, issued by an accredited laboratory (CSTB, Efectis), remains valid for 5 years (order of 22 March 2004 as amended, article 5). In addition, enhanced requirements apply to premises accommodating employees (articles R4216-1 to R4216-31). On our recent projects, EI 30 remains the most frequently selected rating, with EI 60 covering the majority of the remaining cases.
Kytom’s position, at odds with part of the profession. The prevailing wisdom among safety project managers tends to push for the higher rating « as a precaution » during the preliminary design phases. Our reading differs: no safety commission has ever rejected an EI 30 frame compliant with the 1980 order in a category 5 public-access building. Over-specifying to EI 60 outside high-rise buildings brings no regulatory benefit and locks the layout into frames with a 50 to 70 mm visible section, to the detriment of the slim profile sought by the architect.
Correspondence table: building category and required rating
The fire rating of a frame is not chosen from a catalogue: it follows from the category of the establishment and the applicable regulations. The table below summarises the configurations encountered across the French commercial building stock.
| Configuration | Category | Frame rating | Regulatory reference |
|---|---|---|---|
| Standard enclosed office | Category 5 ERP | EI 30 | Order 25/06/1980 |
| Confidential meeting room | Category 5 ERP | EI 30 + Rw 38 dB | Commercial acoustic requirement |
| Functional compartment | IGH W | EI 60 | Order 30/12/2011 |
| Server room or archives | High-risk premises | EI 90 | Labour Code R4216 |
| Wall between IGH compartments | IGH | EI 120 | Order 30/12/2011 |
| Main service shaft | IGH | EI 120 | Order 30/12/2011 |
Consistency is verified during the audit phase, on plan and on site. An EI 60 frame installed in an EI 30 partition does not raise the whole assembly to the higher rating: the weakest link prevails. This cross-check avoids the late reclassifications required by safety commissions during refurbishment operations, a pitfall frequently encountered when the stated rating does not match the actual rating after verification of the test reports.
For the architect: incorporating transparency without bulking up the profile
The acoustic aspect is handled jointly: joinery between enclosed offices or meeting rooms must achieve a sound insulation of Rw = 32 dB for standard confidentiality and Rw ≥ 38 dB for management offices. A well-designed fire-rated frame combines the required EI rating with acoustic performance, without a solid partition as a substitute. Each frame is the subject of a named inspection sheet archived for 10 years.
Measured benefits on delivered floor plates
Using glazed fire-rated frames rather than solid partitions preserves a significant supply of natural light, a parameter built into environmental certification approaches and workplace quality standards. This joinery reduces operating costs and offers a lifespan of more than 25 years with minimal maintenance, while lightening the documentary burden on technical departments during annual audits.
Frequently asked questions
What fire rating for a glazed frame between enclosed offices in a category 5 public-access building?
EI 30 according to the order of 25 June 1980, based on a fire test report valid for 5 years. EI 30 is the most frequently used fire rating in commercial buildings for glazed frames between enclosed offices.
Does an EI 60 frame installed in an EI 30 partition raise the whole assembly to EI 60?
No, the weakest link prevails: the assembly remains classified EI 30. The overall rating of a separating wall corresponds to that of its least performing component, including the frame, partition or joint. During our preliminary audits, KYTOM frequently identifies discrepancies between the rating shown on drawings and the actual rating confirmed after reviewing the test reports issued by CSTB or Efectis.
